1
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Zhao ET, Hull JM, Mintz Hemed N, Uluşan H, Bartram J, Zhang A, Wang P, Pham A, Ronchi S, Huguenard JR, Hierlemann A, Melosh NA. A CMOS-based highly scalable flexible neural electrode interface. Sci Adv 2023; 9:eadf9524. [PMID: 37285436 PMCID: PMC10246892 DOI: 10.1126/sciadv.adf9524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/03/2023] [Indexed: 06/09/2023]
Abstract
Perception, thoughts, and actions are encoded by the coordinated activity of large neuronal populations spread over large areas. However, existing electrophysiological devices are limited by their scalability in capturing this cortex-wide activity. Here, we developed an electrode connector based on an ultra-conformable thin-film electrode array that self-assembles onto silicon microelectrode arrays enabling multithousand channel counts at a millimeter scale. The interconnects are formed using microfabricated electrode pads suspended by thin support arms, termed Flex2Chip. Capillary-assisted assembly drives the pads to deform toward the chip surface, and van der Waals forces maintain this deformation, establishing Ohmic contact. Flex2Chip arrays successfully measured extracellular action potentials ex vivo and resolved micrometer scale seizure propagation trajectories in epileptic mice. We find that seizure dynamics in absence epilepsy in the Scn8a+/- model do not have constant propagation trajectories.
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Affiliation(s)
- Eric T. Zhao
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
| | - Jacob M. Hull
- Department of Neurology, Stanford University, Stanford, CA, USA
| | - Nofar Mintz Hemed
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Hasan Uluşan
- Department of Biosystems Engineering, ETH Zürich, Basel, Switzerland
| | - Julian Bartram
- Department of Biosystems Engineering, ETH Zürich, Basel, Switzerland
| | - Anqi Zhang
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
| | - Pingyu Wang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Albert Pham
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Silvia Ronchi
- Department of Biosystems Engineering, ETH Zürich, Basel, Switzerland
| | | | | | - Nicholas A. Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
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2
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Wang P, Wu EG, Uluşan H, Phillips A, Rose Hays M, Kling A, Zhao ET, Madugula S, Vilkhu RS, Vasireddy PK, Hier- lemann A, Hong G, Chichilnisky E, Melosh NA. Direct-print three-dimensional electrodes for large- scale, high-density, and customizable neural inter- faces. bioRxiv 2023:2023.05.30.542925. [PMID: 37398164 PMCID: PMC10312573 DOI: 10.1101/2023.05.30.542925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Silicon-based planar microelectronics is a powerful tool for scalably recording and modulating neural activity at high spatiotemporal resolution, but it remains challenging to target neural structures in three dimensions (3D). We present a method for directly fabricating 3D arrays of tissue-penetrating microelectrodes onto silicon microelectronics. Leveraging a high-resolution 3D printing technology based on 2-photon polymerization and scalable microfabrication processes, we fabricated arrays of 6,600 microelectrodes 10-130 μm tall and at 35-μm pitch onto a planar silicon-based microelectrode array. The process enables customizable electrode shape, height and positioning for precise targeting of neuron populations distributed in 3D. As a proof of concept, we addressed the challenge of specifically targeting retinal ganglion cell (RGC) somas when interfacing with the retina. The array was customized for insertion into the retina and recording from somas while avoiding the axon layer. We verified locations of the microelectrodes with confocal microscopy and recorded high-resolution spontaneous RGC activity at cellular resolution. This revealed strong somatic and dendritic components with little axon contribution, unlike recordings with planar microelectrode arrays. The technology could be a versatile solution for interfacing silicon microelectronics with neural structures and modulating neural activity at large scale with single-cell resolution.
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Affiliation(s)
- Pingyu Wang
- Department of Materials Science and Engineering, Stanford University
| | - Eric G. Wu
- Department of Electrical Engineering, Stanford University, Stanford University
| | - Hasan Uluşan
- Department of Biosystems Science and Engineering in Basel, ETH Zürich
| | - A.J. Phillips
- Department of Electrical Engineering, Stanford University, Stanford University
| | | | | | - Eric T. Zhao
- Department of Chemical Engineering, Stanford University
| | | | - Ramandeep S. Vilkhu
- Department of Electrical Engineering, Stanford University, Stanford University
| | | | | | - Guosong Hong
- Department of Materials Science and Engineering, Stanford University
| | - E.J. Chichilnisky
- Department of Neurosurgery, Stanford University
- Hansen Experimental Physics Laboratory, Stanford University
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3
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Mintz Hemed N, Leal-Ortiz S, Zhao ET, Melosh NA. On-Demand, Reversible, Ultrasensitive Polymer Membrane Based on Molecular Imprinting Polymer. ACS Nano 2023; 17:5632-5643. [PMID: 36913954 PMCID: PMC10062346 DOI: 10.1021/acsnano.2c11618] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
The development of in vivo, longitudinal, real-time monitoring devices is an essential step toward continuous, precision health monitoring. Molecularly imprinted polymers (MIPs) are popular sensor capture agents that are more robust than antibodies and have been used for sensors, drug delivery, affinity separations, assays, and solid-phase extraction. However, MIP sensors are typically limited to one-time use due to their high binding affinity (>107 M-1) and slow-release kinetics (<10-4 μM/sec). To overcome this challenge, current research has focused on stimuli-responsive MIPs (SR-MIPs), which undergo a conformational change induced by external stimuli to reverse molecular binding, requiring additional chemicals or outside stimuli. Here, we demonstrate fully reversible MIP sensors based on electrostatic repulsion. Once the target analyte is bound within a thin film MIP on an electrode, a small electrical potential successfully releases the bound molecules, enabling repeated, accurate measurements. We demonstrate an electrostatically refreshed dopamine sensor with a 760 pM limit of detection, linear response profile, and accuracy even after 30 sensing-release cycles. These sensors could repeatedly detect <1 nM dopamine released from PC-12 cells in vitro, demonstrating they can longitudinally measure low concentrations in complex biological environments without clogging. Our work provides a simple and effective strategy for enhancing the use of MIPs-based biosensors for all charged molecules in continuous, real-time health monitoring and other sensing applications.
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Affiliation(s)
- Nofar Mintz Hemed
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
| | - Sergio Leal-Ortiz
- Department
of Psychiatry and Behavioral Sciences, Stanford
University, Stanford, California 94304, United States
| | - Eric T. Zhao
- Department
of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Nicholas A. Melosh
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
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4
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Mintz Hemed N, Melosh NA. An integrated perspective for the diagnosis and therapy of neurodevelopmental disorders - From an engineering point of view. Adv Drug Deliv Rev 2023; 194:114723. [PMID: 36746077 DOI: 10.1016/j.addr.2023.114723] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/14/2022] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
Neurodevelopmental disorders (NDDs) are complex conditions with largely unknown pathophysiology. While many NDD symptoms are familiar, the cause of these disorders remains unclear and may involve a combination of genetic, biological, psychosocial, and environmental risk factors. Current diagnosis relies heavily on behaviorally defined criteria, which may be biased by the clinical team's professional and cultural expectations, thus a push for new biological-based biomarkers for NDDs diagnosis is underway. Emerging new research technologies offer an unprecedented view into the electrical, chemical, and physiological activity in the brain and with further development in humans may provide clinically relevant diagnoses. These could also be extended to new treatment options, which can start to address the underlying physiological issues. When combined with current speech, language, occupational therapy, and pharmacological treatment these could greatly improve patient outcomes. The current review will discuss the latest technologies that are being used or may be used for NDDs diagnosis and treatment. The aim is to provide an inspiring and forward-looking view for future research in the field.
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Affiliation(s)
- Nofar Mintz Hemed
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
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5
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Hall RN, Weill U, Drees L, Leal-Ortiz S, Li H, Khariton M, Chai C, Xue Y, Rosental B, Quake SR, Sánchez Alvarado A, Melosh NA, Fire AZ, Rink JC, Wang B. Heterologous reporter expression in the planarian Schmidtea mediterranea through somatic mRNA transfection. Cell Rep Methods 2022; 2:100298. [PMID: 36313809 PMCID: PMC9606109 DOI: 10.1016/j.crmeth.2022.100298] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/11/2022] [Accepted: 08/25/2022] [Indexed: 06/16/2023]
Abstract
Planarians have long been studied for their regenerative abilities. Moving forward, tools for ectopic expression of non-native proteins will be of substantial value. Using a luminescent reporter to overcome the strong autofluorescence of planarian tissues, we demonstrate heterologous protein expression in planarian cells and live animals. Our approach is based on the introduction of mRNA through several nanotechnological and chemical transfection methods. We improve reporter expression by altering untranslated region (UTR) sequences and codon bias, facilitating the measurement of expression kinetics in both isolated cells and whole planarians using luminescence imaging. We also examine protein expression as a function of variations in the UTRs of delivered mRNA, demonstrating a framework to investigate gene regulation at the post-transcriptional level. Together, these advances expand the toolbox for the mechanistic analysis of planarian biology and establish a foundation for the development and expansion of transgenic techniques in this unique model system.
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Affiliation(s)
| | - Uri Weill
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Leonard Drees
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Sergio Leal-Ortiz
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Hongquan Li
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Margarita Khariton
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Benyamin Rosental
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Center for Regenerative Medicine and Stem Cells, Ben Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Stephen R. Quake
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
- Howard Hughes Medical Institute, Kansas City, MO 64110, USA
| | - Nicholas A. Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Andrew Z. Fire
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jochen C. Rink
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
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6
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Li S, Francaviglia L, Kohler DD, Jones ZR, Zhao ET, Ogletree DF, Weber-Bargioni A, Melosh NA, Hamers RJ. Ag-Diamond Core-Shell Nanostructures Incorporated with Silicon-Vacancy Centers. ACS Mater Au 2021; 2:85-93. [PMID: 36855764 PMCID: PMC9888652 DOI: 10.1021/acsmaterialsau.1c00027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Silicon-vacancy (SiV) centers in diamond have attracted attention as highly stable fluorophores for sensing and as possible candidates for quantum information science. While prior studies have shown that the formation of hybrid diamond-metal structures can increase the rates of optical absorption and emission, many practical applications require diamond plasmonic structures that are stable in harsh chemical and thermal environments. Here, we demonstrate that Ag nanospheres, produced both in quasi-random arrays by thermal dewetting and in ordered arrays using electron-beam lithography, can be completely encapsulated with a thin diamond coating containing SiV centers, leading to hybrid core-shell nanostructures exhibiting extraordinary chemical and thermal stability as well as enhanced optical properties. Diamond shells with a thickness on the order of 20-100 nm are sufficient to encapsulate and protect the Ag nanostructures with different sizes ranging from 20 nm to hundreds of nanometers, allowing them to withstand heating to temperatures of 1000 °C and immersion in harsh boiling acid for 24 h. Ultrafast photoluminescence lifetime and super-resolution optical imaging experiments were used to study the SiV properties on and off the core-shell structures, which show that the SiV on core-shell structures have higher brightness and faster decay rate. The stability and optical properties of the hybrid Ag-diamond core-shell structures make them attractive candidates for high-efficiency imaging and quantum-based sensing applications.
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Affiliation(s)
- Shuo Li
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States,Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States,Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
| | - Luca Francaviglia
- Molecular
Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel D. Kohler
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Zachary R. Jones
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Eric T. Zhao
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
| | - D. Frank Ogletree
- Molecular
Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alexander Weber-Bargioni
- Molecular
Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nicholas A. Melosh
- Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States,Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States,
| | - Robert J. Hamers
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States,
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7
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Kollo M, Racz R, Hanna ME, Obaid A, Angle MR, Wray W, Kong Y, Müller J, Hierlemann A, Melosh NA, Schaefer AT. CHIME: CMOS-Hosted in vivo Microelectrodes for Massively Scalable Neuronal Recordings. Front Neurosci 2020; 14:834. [PMID: 32848584 PMCID: PMC7432274 DOI: 10.3389/fnins.2020.00834] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/16/2020] [Indexed: 01/20/2023] Open
Abstract
Mammalian brains consist of 10s of millions to 100s of billions of neurons operating at millisecond time scales, of which current recording techniques only capture a tiny fraction. Recording techniques capable of sampling neural activity at high spatiotemporal resolution have been difficult to scale. The most intensively studied mammalian neuronal networks, such as the neocortex, show a layered architecture, where the optimal recording technology samples densely over large areas. However, the need for application-specific designs as well as the mismatch between the three-dimensional architecture of the brain and largely two-dimensional microfabrication techniques profoundly limits both neurophysiological research and neural prosthetics. Here, we discuss a novel strategy for scalable neuronal recording by combining bundles of glass-ensheathed microwires with large-scale amplifier arrays derived from high-density CMOS in vitro MEA systems or high-speed infrared cameras. High signal-to-noise ratio (<25 μV RMS noise floor, SNR up to 25) is achieved due to the high conductivity of core metals in glass-ensheathed microwires allowing for ultrathin metal cores (down to <1 μm) and negligible stray capacitance. Multi-step electrochemical modification of the tip enables ultra-low access impedance with minimal geometric area, which is largely independent of the core diameter. We show that the microwire size can be reduced to virtually eliminate damage to the blood-brain-barrier upon insertion and we demonstrate that microwire arrays can stably record single-unit activity. Combining microwire bundles and CMOS arrays allows for a highly scalable neuronal recording approach, linking the progress in electrical neuronal recordings to the rapid progress in silicon microfabrication. The modular design of the system allows for custom arrangement of recording sites. Our approach of employing bundles of minimally invasive, highly insulated and functionalized microwires to extend a two-dimensional CMOS architecture into the 3rd dimension can be translated to other CMOS arrays, such as electrical stimulation devices.
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Affiliation(s)
- Mihaly Kollo
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, United Kingdom
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Romeo Racz
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, United Kingdom
| | - Mina-Elraheb Hanna
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, United States
- Paradromics, Inc., Austin, TX, United States
| | - Abdulmalik Obaid
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, United States
| | | | - William Wray
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, United Kingdom
| | - Yifan Kong
- Paradromics, Inc., Austin, TX, United States
| | - Jan Müller
- ETH Zürich, Department of Biosystems Science and Engineering, Basel, Switzerland
- MaxWell Biosystems AG, Zurich, Switzerland
| | - Andreas Hierlemann
- ETH Zürich, Department of Biosystems Science and Engineering, Basel, Switzerland
| | - Nicholas A. Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, United States
| | - Andreas T. Schaefer
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, United Kingdom
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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8
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Rugar AE, Lu H, Dory C, Sun S, McQuade PJ, Shen ZX, Melosh NA, Vučković J. Generation of Tin-Vacancy Centers in Diamond via Shallow Ion Implantation and Subsequent Diamond Overgrowth. Nano Lett 2020; 20:1614-1619. [PMID: 32031821 DOI: 10.1021/acs.nanolett.9b04495] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Group IV color centers in diamond have garnered great interest for their potential as optically active solid-state spin qubits. The future utilization of such emitters requires the development of precise site-controlled emitter generation techniques that are compatible with high-quality nanophotonic devices. This task is more challenging for color centers with large group IV impurity atoms, which are otherwise promising because of their predicted long spin coherence times without a dilution refrigerator. For example, when applied to the negatively charged tin-vacancy (SnV-) center, conventional site-controlled color center generation methods either damage the diamond surface or yield bulk spectra with unexplained features. Here we demonstrate a novel method to generate site-controlled SnV- centers with clean bulk spectra. We shallowly implant Sn ions through a thin implantation mask and subsequently grow a layer of diamond via chemical vapor deposition. This method can be extended to other color centers and integrated with quantum nanophotonic device fabrication.
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Affiliation(s)
| | | | | | | | - Patrick J McQuade
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Zhi-Xun Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Nicholas A Melosh
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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9
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Obaid A, Hanna ME, Wu YW, Kollo M, Racz R, Angle MR, Müller J, Brackbill N, Wray W, Franke F, Chichilnisky EJ, Hierlemann A, Ding JB, Schaefer AT, Melosh NA. Massively parallel microwire arrays integrated with CMOS chips for neural recording. Sci Adv 2020; 6:eaay2789. [PMID: 32219158 PMCID: PMC7083623 DOI: 10.1126/sciadv.aay2789] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 12/26/2019] [Indexed: 05/21/2023]
Abstract
Multi-channel electrical recordings of neural activity in the brain is an increasingly powerful method revealing new aspects of neural communication, computation, and prosthetics. However, while planar silicon-based CMOS devices in conventional electronics scale rapidly, neural interface devices have not kept pace. Here, we present a new strategy to interface silicon-based chips with three-dimensional microwire arrays, providing the link between rapidly-developing electronics and high density neural interfaces. The system consists of a bundle of microwires mated to large-scale microelectrode arrays, such as camera chips. This system has excellent recording performance, demonstrated via single unit and local-field potential recordings in isolated retina and in the motor cortex or striatum of awake moving mice. The modular design enables a variety of microwire types and sizes to be integrated with different types of pixel arrays, connecting the rapid progress of commercial multiplexing, digitisation and data acquisition hardware together with a three-dimensional neural interface.
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Affiliation(s)
- Abdulmalik Obaid
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Mina-Elraheb Hanna
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- Paradromics Inc., Austin, TX, USA
| | - Yu-Wei Wu
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Mihaly Kollo
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Romeo Racz
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
| | | | - Jan Müller
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Nora Brackbill
- Department of Physics, Stanford University, Stanford, CA, USA
| | - William Wray
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
| | - Felix Franke
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - E. J. Chichilnisky
- Departments of Neurosurgery and Ophthalmology, Stanford University, Stanford, CA, USA
| | - Andreas Hierlemann
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Jun B. Ding
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Andreas T. Schaefer
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Nicholas A. Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
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10
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Wang H, Tzeng YK, Ji Y, Li Y, Li J, Zheng X, Yang A, Liu Y, Gong Y, Cai L, Li Y, Zhang X, Chen W, Liu B, Lu H, Melosh NA, Shen ZX, Chan K, Tan T, Chu S, Cui Y. Synergistic enhancement of electrocatalytic CO 2 reduction to C 2 oxygenates at nitrogen-doped nanodiamonds/Cu interface. Nat Nanotechnol 2020; 15:131-137. [PMID: 31907442 DOI: 10.1038/s41565-019-0603-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/24/2019] [Indexed: 05/03/2023]
Abstract
To date, effective control over the electrochemical reduction of CO2 to multicarbon products (C ≥ 2) has been very challenging. Here, we report a design principle for the creation of a selective yet robust catalytic interface for heterogeneous electrocatalysts in the reduction of CO2 to C2 oxygenates, demonstrated by rational tuning of an assembly of nitrogen-doped nanodiamonds and copper nanoparticles. The catalyst exhibits a Faradaic efficiency of ~63% towards C2 oxygenates at applied potentials of only -0.5 V versus reversible hydrogen electrode. Moreover, this catalyst shows an unprecedented persistent catalytic performance up to 120 h, with steady current and only 19% activity decay. Density functional theory calculations show that CO binding is strengthened at the copper/nanodiamond interface, suppressing CO desorption and promoting C2 production by lowering the apparent barrier for CO dimerization. The inherent compositional and electronic tunability of the catalyst assembly offers an unrivalled degree of control over the catalytic interface, and thereby the reaction energetics and kinetics.
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Affiliation(s)
- Hongxia Wang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, China
| | - Yan-Kai Tzeng
- Department of Physics, Stanford University, Stanford, CA, USA
| | - Yongfei Ji
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Yanbin Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Jun Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Xueli Zheng
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Ankun Yang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Yayuan Liu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Yongji Gong
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Lili Cai
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Yuzhang Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Xiaokun Zhang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Wei Chen
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Bofei Liu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Haiyu Lu
- Department of Physics, Stanford University, Stanford, CA, USA
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Zhi-Xun Shen
- Department of Physics, Stanford University, Stanford, CA, USA
- Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Karen Chan
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
| | - Tianwei Tan
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, China.
- National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing, China.
| | - Steven Chu
- Department of Physics, Stanford University, Stanford, CA, USA.
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
| | - Yi Cui
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA.
- Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
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11
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Abstract
Rigid, cage-like molecules, like diamondoids, show unique self-assembly behavior, such as templating 1-D nanomaterial assembly via pathways that are typically blocked for such bulky substituents. We investigate molecular forces between diamondoids to explore why molecules with high structural rigidity exhibit these novel assembly pathways. The rigid nature of diamondoids significantly lowers configurational entropy, and we hypothesize that this influences molecular interaction forces. To test this concept, we calculated the distance-dependent impact of entropy on assembly using molecular dynamics simulations. To isolate pairwise entropic and enthalpic contributions to assembly, we considered pairs of molecules in a thermal bath, fixed at set intermolecular separations but otherwise allowed to freely move. By comparing diamondoids to linear alkanes, we draw out the impact of rigidity on the entropy and enthalpy of pairwise interactions. We find that linear alkanes actually exhibit stronger van der Waals interactions than diamondoids at contact, because the bulky structure of diamondoids induces larger net atomic separations. Yet, we also find that diamondoids pay lower entropic penalties when assembling into contact pairs. Thus, the cage-like shape of diamondoids introduces an enthalpic penalty at contact, but the penalty is counterbalanced by entropic effects. Investigating the distance dependence of entropic forces provides a mechanism to explore how rigidity influences molecular assembly. Our results show that low entropic penalties paid by diamondoids can explain the effectiveness of diamondoids in templating nanomaterial assembly. Hence, tuning molecular rigidity can be an effective strategy for controlling the assembly of functional materials, such as biomimetic surfaces and nanoscale materials.
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Affiliation(s)
- Ella M King
- Geballe Laboratory for Advanced Materials , Stanford University , Stanford , California 94305 , United States
- Department of Physics , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Matthew A Gebbie
- Geballe Laboratory for Advanced Materials , Stanford University , Stanford , California 94305 , United States
- Department of Chemical and Biological Engineering , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Nicholas A Melosh
- Geballe Laboratory for Advanced Materials , Stanford University , Stanford , California 94305 , United States
- Department of Materials Science and Engineering , Stanford University , Stanford , California 94305 , United States
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12
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Affiliation(s)
- Nicholas A Melosh
- Materials Science and Engineering Department, Stanford University, Stanford, CA, USA.
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13
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Schindler P, Riley DC, Bargatin I, Sahasrabuddhe K, Schwede JW, Sun S, Pianetta P, Shen ZX, Howe RT, Melosh NA. Surface Photovoltage-Induced Ultralow Work Function Material for Thermionic Energy Converters. ACS Energy Lett 2019; 4:2436-2443. [PMID: 31633034 PMCID: PMC6792473 DOI: 10.1021/acsenergylett.9b01214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Low work function materials are essential for efficient thermionic energy converters (TECs), electronics, and electron emission devices. Much effort has been put into finding thermally stable material combinations that exhibit low work functions. Submonolayer coatings of alkali metals have proven to significantly reduce the work function; however, a work function less than 1 eV has not been reached. We report a record-low work function of 0.70 eV by inducing a surface photovoltage (SPV) in an n-type semiconductor with an alkali metal coating. Ultraviolet photoelectron spectroscopy indicates a work function of 1.06 eV for cesium/oxygen-activated GaAs consistent with density functional theory model predictions. By illuminating with a 532 nm laser we induce an additional shift down to 0.70 eV due to the SPV. Further, we apply the SPV to the collector of an experimental TEC and demonstrate an I-V curve shift consistent with the collector work function reduction. This method opens an avenue toward efficient TECs and next-generation electron emission devices.
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Affiliation(s)
- Peter Schindler
- Department
of Electrical Engineering, Stanford University, Stanford, California 94305, United States
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
| | - Daniel C. Riley
- Geballe
Laboratory for Advanced Materials, Stanford
University, Stanford, California 94305, United States
- Department
of Applied Physics, Stanford University, Stanford, California 94305, United States
- Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Cyclotron
Road, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Igor Bargatin
- Department
of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, United States
| | - Kunal Sahasrabuddhe
- Geballe
Laboratory for Advanced Materials, Stanford
University, Stanford, California 94305, United States
- Department
of Applied Physics, Stanford University, Stanford, California 94305, United States
- Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jared W. Schwede
- Geballe
Laboratory for Advanced Materials, Stanford
University, Stanford, California 94305, United States
- Department
of Applied Physics, Stanford University, Stanford, California 94305, United States
- Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Steven Sun
- Stanford
Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Piero Pianetta
- Department
of Electrical Engineering, Stanford University, Stanford, California 94305, United States
- Stanford
Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Zhi-Xun Shen
- Geballe
Laboratory for Advanced Materials, Stanford
University, Stanford, California 94305, United States
- Department
of Applied Physics, Stanford University, Stanford, California 94305, United States
- Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Roger T. Howe
- Department
of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Nicholas A. Melosh
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
- Geballe
Laboratory for Advanced Materials, Stanford
University, Stanford, California 94305, United States
- Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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14
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Nicaise SM, Lin C, Azadi M, Bozorg-Grayeli T, Adebayo-Ige P, Lilley DE, Pfitzer Y, Cha W, Van Houten K, Melosh NA, Howe RT, Schwede JW, Bargatin I. Micron-gap spacers with ultrahigh thermal resistance and mechanical robustness for direct energy conversion. Microsyst Nanoeng 2019; 5:31. [PMID: 31636923 PMCID: PMC6799816 DOI: 10.1038/s41378-019-0071-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/28/2019] [Accepted: 04/02/2019] [Indexed: 05/22/2023]
Abstract
In thermionic energy converters, the absolute efficiency can be increased up to 40% if space-charge losses are eliminated by using a sub-10-µm gap between the electrodes. One practical way to achieve such small gaps over large device areas is to use a stiff and thermally insulating spacer between the two electrodes. We report on the design, fabrication and characterization of thin-film alumina-based spacers that provided robust 3-8 μm gaps between planar substrates and had effective thermal conductivities less than those of aerogels. The spacers were fabricated on silicon molds and, after release, could be manually transferred onto any substrate. In large-scale compression testing, they sustained compressive stresses of 0.4-4 MPa without fracture. Experimentally, the thermal conductance was 10-30 mWcm-2K-1 and, surprisingly, independent of film thickness (100-800 nm) and spacer height. To explain this independence, we developed a model that includes the pressure-dependent conductance of locally distributed asperities and sparse contact points throughout the spacer structure, indicating that only 0.1-0.5% of the spacer-electrode interface was conducting heat. Our spacers show remarkable functionality over multiple length scales, providing insulating micrometer gaps over centimeter areas using nanoscale films. These innovations can be applied to other technologies requiring high thermal resistance in small spaces, such as thermophotovoltaic converters, insulation for spacecraft and cryogenic devices.
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Affiliation(s)
- Samuel M. Nicaise
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Chen Lin
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Mohsen Azadi
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Tara Bozorg-Grayeli
- Materials Science & Engineering, Stanford University, Stanford, 94305 CA USA
| | - Promise Adebayo-Ige
- Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA USA
| | - Drew E. Lilley
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Yann Pfitzer
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Wujoon Cha
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
| | | | - Nicholas A. Melosh
- Materials Science & Engineering, Stanford University, Stanford, 94305 CA USA
| | - Roger T. Howe
- Electrical Engineering, Stanford University, Stanford, CA 94305 USA
| | | | - Igor Bargatin
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104 USA
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15
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Sun S, Zhang JL, Fischer KA, Burek MJ, Dory C, Lagoudakis KG, Tzeng YK, Radulaski M, Kelaita Y, Safavi-Naeini A, Shen ZX, Melosh NA, Chu S, Lončar M, Vučković J. Cavity-Enhanced Raman Emission from a Single Color Center in a Solid. Phys Rev Lett 2018; 121:083601. [PMID: 30192607 DOI: 10.1103/physrevlett.121.083601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate cavity-enhanced Raman emission from a single atomic defect in a solid. Our platform is a single silicon-vacancy center in diamond coupled with a monolithic diamond photonic crystal cavity. The cavity enables an unprecedented frequency tuning range of the Raman emission (100 GHz) that significantly exceeds the spectral inhomogeneity of silicon-vacancy centers in diamond nanostructures. We also show that the cavity selectively suppresses the phonon-induced spontaneous emission that degrades the efficiency of Raman photon generation. Our results pave the way towards photon-mediated many-body interactions between solid-state quantum emitters in a nanophotonic platform.
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Affiliation(s)
- Shuo Sun
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | | | - Kevin A Fischer
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | - Michael J Burek
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Constantin Dory
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | | | - Yan-Kai Tzeng
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Marina Radulaski
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | - Yousif Kelaita
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | - Amir Safavi-Naeini
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | - Zhi-Xun Shen
- Department of Physics, Stanford University, Stanford, California 94305, USA
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Nicholas A Melosh
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Steven Chu
- Department of Physics, Stanford University, Stanford, California 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, USA
| | - Marko Lončar
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Jelena Vučković
- E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
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16
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Yan H, Narasimha KT, Denlinger J, Li FH, Mo SK, Hohman JN, Dahl JEP, Carlson RMK, Tkachenko BA, Fokin AA, Schreiner PR, Hussain Z, Shen ZX, Melosh NA. Monochromatic Photocathodes from Graphene-Stabilized Diamondoids. Nano Lett 2018; 18:1099-1103. [PMID: 29286670 DOI: 10.1021/acs.nanolett.7b04645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The monochromatic photoemission from diamondoid monolayers provides a new strategy to create electron sources with low energy dispersion and enables compact electron guns with high brightness and low beam emittance for aberration-free imaging, lithography, and accelerators. However, these potential applications are hindered by degradation of diamondoid monolayers under photon irradiation and electron bombardment. Here, we report a graphene-protected diamondoid monolayer photocathode with 4-fold enhancement of stability compared to the bare diamondoid counterpart. The single-layer graphene overcoating preserves the monochromaticity of the photoelectrons, showing 12.5 meV ful width at half-maximum distribution of kinetic energy. Importantly, the graphene coating effectively suppresses desorption of the diamondoid monolayer, enhancing its thermal stability by at least 100 K. Furthermore, by comparing the decay rate at different photon energies, we identify electron bombardment as the principle decay pathway for diamondoids under graphene protection. This provides a generic approach for stabilizing volatile species on photocathode surfaces, which could greatly improve performance of electron emitters.
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Affiliation(s)
- Hao Yan
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
| | - Karthik T Narasimha
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
| | - Jonathan Denlinger
- Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Fei Hua Li
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
| | - Sung-Kwan Mo
- Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - J Nathan Hohman
- Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Jeremy E P Dahl
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
| | - Robert M K Carlson
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
| | | | - Andrey A Fokin
- Institute of Organic Chemistry, Justus-Liebig University , Giessen, Germany
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University , Giessen, Germany
| | - Zahid Hussain
- Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Zhi-Xun Shen
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
- Department of Applied Physics, Stanford University , Stanford, California 94305, United States
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences , Stanford, California 94305, United States
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17
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Zhang JL, Sun S, Burek MJ, Dory C, Tzeng YK, Fischer KA, Kelaita Y, Lagoudakis KG, Radulaski M, Shen ZX, Melosh NA, Chu S, Lončar M, Vučković J. Strongly Cavity-Enhanced Spontaneous Emission from Silicon-Vacancy Centers in Diamond. Nano Lett 2018; 18:1360-1365. [PMID: 29377701 DOI: 10.1021/acs.nanolett.7b05075] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Quantum emitters are an integral component for a broad range of quantum technologies, including quantum communication, quantum repeaters, and linear optical quantum computation. Solid-state color centers are promising candidates for scalable quantum optics due to their long coherence time and small inhomogeneous broadening. However, once excited, color centers often decay through phonon-assisted processes, limiting the efficiency of single-photon generation and photon-mediated entanglement generation. Herein, we demonstrate strong enhancement of spontaneous emission rate of a single silicon-vacancy center in diamond embedded within a monolithic optical cavity, reaching a regime in which the excited-state lifetime is dominated by spontaneous emission into the cavity mode. We observe 10-fold lifetime reduction and 42-fold enhancement in emission intensity when the cavity is tuned into resonance with the optical transition of a single silicon-vacancy center, corresponding to 90% of the excited-state energy decay occurring through spontaneous emission into the cavity mode. We also demonstrate the largest coupling strength (g/2π = 4.9 ± 0.3 GHz) and cooperativity (C = 1.4) to date for color-center-based cavity quantum electrodynamics systems, bringing the system closer to the strong coupling regime.
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Affiliation(s)
| | | | - Michael J Burek
- School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
| | | | | | | | | | | | | | - Zhi-Xun Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | - Nicholas A Melosh
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | | | - Marko Lončar
- School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
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18
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Sander J, Schmidt SV, Cirovic B, McGovern N, Papantonopoulou O, Hardt AL, Aschenbrenner AC, Kreer C, Quast T, Xu AM, Schmidleithner LM, Theis H, Thi Huong LD, Sumatoh HRB, Lauterbach MAR, Schulte-Schrepping J, Günther P, Xue J, Baßler K, Ulas T, Klee K, Katzmarski N, Herresthal S, Krebs W, Martin B, Latz E, Händler K, Kraut M, Kolanus W, Beyer M, Falk CS, Wiegmann B, Burgdorf S, Melosh NA, Newell EW, Ginhoux F, Schlitzer A, Schultze JL. Cellular Differentiation of Human Monocytes Is Regulated by Time-Dependent Interleukin-4 Signaling and the Transcriptional Regulator NCOR2. Immunity 2017; 47:1051-1066.e12. [PMID: 29262348 PMCID: PMC5772172 DOI: 10.1016/j.immuni.2017.11.024] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 09/15/2017] [Accepted: 11/28/2017] [Indexed: 12/24/2022]
Abstract
Human in vitro generated monocyte-derived dendritic cells (moDCs) and macrophages are used clinically, e.g., to induce immunity against cancer. However, their physiological counterparts, ontogeny, transcriptional regulation, and heterogeneity remains largely unknown, hampering their clinical use. High-dimensional techniques were used to elucidate transcriptional, phenotypic, and functional differences between human in vivo and in vitro generated mononuclear phagocytes to facilitate their full potential in the clinic. We demonstrate that monocytes differentiated by macrophage colony-stimulating factor (M-CSF) or granulocyte macrophage colony-stimulating factor (GM-CSF) resembled in vivo inflammatory macrophages, while moDCs resembled in vivo inflammatory DCs. Moreover, differentiated monocytes presented with profound transcriptomic, phenotypic, and functional differences. Monocytes integrated GM-CSF and IL-4 stimulation combinatorically and temporally, resulting in a mode- and time-dependent differentiation relying on NCOR2. Finally, moDCs are phenotypically heterogeneous and therefore necessitate the use of high-dimensional phenotyping to open new possibilities for better clinical tailoring of these cellular therapies. In vitro monocyte cultures model in vivo inflammatory dendritic cells and macrophages Monocyte-derived dendritic cells integrate interleukin-4 signaling time dependently NCOR2 controls differentiation of in vitro generated monocyte-derived dendritic cells In vitro generated monocyte-derived cells are phenotypically heterogeneous
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Affiliation(s)
- Jil Sander
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Susanne V Schmidt
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany
| | - Branko Cirovic
- Myeloid Cell Biology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Naomi McGovern
- Agency for Science, Technology and Research (A(∗)STAR), Singapore Immunology Network (SIgN), 138648 Singapore, Singapore; Department of Pathology and Center for Trophoblast Research, University of Cambridge, CB2 1QP Cambridge, UK
| | | | - Anna-Lena Hardt
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Anna C Aschenbrenner
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Christoph Kreer
- Cellular Immunology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Thomas Quast
- Molecular Immunology & Cell Biology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Alexander M Xu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Lisa M Schmidleithner
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Heidi Theis
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Lan Do Thi Huong
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Hermi Rizal Bin Sumatoh
- Agency for Science, Technology and Research (A(∗)STAR), Singapore Immunology Network (SIgN), 138648 Singapore, Singapore
| | - Mario A R Lauterbach
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany
| | | | - Patrick Günther
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Jia Xue
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Kevin Baßler
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Thomas Ulas
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Kathrin Klee
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Natalie Katzmarski
- Myeloid Cell Biology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Stefanie Herresthal
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Wolfgang Krebs
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Bianca Martin
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany; Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; German Center for Neurodegenerative Diseases, 53127 Bonn, Germany
| | - Kristian Händler
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Michael Kraut
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Waldemar Kolanus
- Molecular Immunology & Cell Biology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Marc Beyer
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany; Molecular Immunology, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Christine S Falk
- Institute of Transplant Immunology, Integrated Research and Treatment Center Transplantation, Hannover Medical School, 30625 Hannover, Germany
| | - Bettina Wiegmann
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, 30625 Hannover, Germany
| | - Sven Burgdorf
- Cellular Immunology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Evan W Newell
- Agency for Science, Technology and Research (A(∗)STAR), Singapore Immunology Network (SIgN), 138648 Singapore, Singapore
| | - Florent Ginhoux
- Agency for Science, Technology and Research (A(∗)STAR), Singapore Immunology Network (SIgN), 138648 Singapore, Singapore
| | - Andreas Schlitzer
- Myeloid Cell Biology, LIMES-Institute, University of Bonn, 53115 Bonn, Germany; Agency for Science, Technology and Research (A(∗)STAR), Singapore Immunology Network (SIgN), 138648 Singapore, Singapore.
| | - Joachim L Schultze
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn, 53115 Bonn, Germany; Platform for Single Cell Genomics and Epigenomics (PRECISE) at the German Center for Neurodegenerative Diseases and the University of Bonn, 53127 Bonn, Germany
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19
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Abstract
Fluidic control and sampling in complex environments is an important process in biotechnology, materials synthesis, and microfluidics. An elegant solution to this problem has evolved in nature through cellular endocytosis, where the dynamic recruitment, self-assembly, and spherical budding of clathrin proteins allows cells to sample their external environment. Yet despite the importance and utility of endocytosis, artificial systems which can replicate this dynamic behavior have not been developed. Guided by clathrin's unusual structure, we created simplified metallic microparticles that capture the three-legged shape, particle curvature, and interfacial attachment characteristics of clathrin. These artificial clathrin mimics successfully recreate biomimetic analogues of clathrin's recruitment, assembly, and budding, ultimately forming extended networks at fluid interfaces and invaginating immiscible phases into spheres under external fields. Particle curvature was discovered to be a critical structural motif, greatly limiting irreversible aggregation and inducing the legs' selective tip-to-tip attraction. This architecture provides a template for a class of active self-assembly units to drive structural and dimensional transformations of liquid-liquid interfaces and microscale fluidic sampling.
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Affiliation(s)
- Yifan Kong
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
| | - Mina-Elraheb S Hanna
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
| | - Denys Zhuo
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
| | - Katherine G Chang
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
| | - Tara Bozorg-Grayeli
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
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20
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Zhang L, Sun L, Guan Z, Lee S, Li Y, Deng HD, Li Y, Ahlborg NL, Boloor M, Melosh NA, Chueh WC. Quantifying and Elucidating Thermally Enhanced Minority Carrier Diffusion Length Using Radius-Controlled Rutile Nanowires. Nano Lett 2017; 17:5264-5272. [PMID: 28817772 DOI: 10.1021/acs.nanolett.7b01504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The minority carrier diffusion length (LD) is a crucial property that determines the performance of light absorbers in photoelectrochemical (PEC) cells. Many transition-metal oxides are stable photoanodes for solar water splitting but exhibit a small to moderate LD, ranging from a few nanometers (such as α-Fe2O3 and TiO2) to a few tens of nanometers (such as BiVO4). Under operating conditions, the temperature of PEC cells can deviate substantially from ambient, yet the temperature dependence of LD has not been quantified. In this work, we show that measuring the photocurrent as a function of both temperature and absorber dimensions provides a quantitative method for evaluating the temperature-dependent minority carrier transport. By measuring photocurrents of nonstoichiometric rutile TiO2-x nanowires as a function of wire radius (19-75 nm) and temperature (10-70 °C), we extract the minority carrier diffusion length along with its activation energy. The minority carrier diffusion length in TiO2-x increases from 5 nm at 25 °C to 10 nm at 70 °C, implying that enhanced carrier mobility outweighs the increase in the recombination rate with temperature. Additionally, by comparing the temperature-dependent photocurrent in BiVO4, TiO2, and α-Fe2O3, we conclude that the ratio of the minority carrier diffusion length to the depletion layer width determines the extent of temperature enhancement, and reconcile the widespread temperature coefficients, which ranged from 0.6 to 1.7% K-1. This insight provides a general design rule to select light absorbers for large thermally activated photocurrents and to predict PEC cell characteristics at a range of temperatures encountered during realistic device operation.
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Affiliation(s)
- Liming Zhang
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Litianqi Sun
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Zixuan Guan
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Sangchul Lee
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Yingzhou Li
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Haitao D Deng
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Yiyang Li
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Nadia L Ahlborg
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Madhur Boloor
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - Nicholas A Melosh
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
| | - William C Chueh
- Department of Materials Science & Engineering, ‡Department of Applied Physics, §Institute for Computational & Mathematical Engineering (ICME), Stanford University , Stanford, California 94305, United States
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21
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Xu AM, Wang DS, Shieh P, Cao Y, Melosh NA. Direct Intracellular Delivery of Cell-Impermeable Probes of Protein Glycosylation by Using Nanostraws. Chembiochem 2017; 18:623-628. [PMID: 28130882 DOI: 10.1002/cbic.201600689] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Indexed: 12/24/2022]
Abstract
Bioorthogonal chemistry is an effective tool for elucidating metabolic pathways and measuring cellular activity, yet its use is currently limited by the difficulty of getting probes past the cell membrane and into the cytoplasm, especially if more complex probes are desired. Here we present a simple and minimally perturbative technique to deliver functional probes of glycosylation into cells by using a nanostructured "nanostraw" delivery system. Nanostraws provide direct intracellular access to cells through fluid conduits that remain small enough to minimize cell perturbation. First, we demonstrate that our platform can deliver an unmodified azidosugar, N-azidoacetylmannosamine, into cells with similar effectiveness to a chemical modification strategy (peracetylation). We then show that the nanostraw platform enables direct delivery of an azidosugar modified with a charged uridine diphosphate group (UDP) that prevents intracellular penetration, thereby bypassing multiple enzymatic processing steps. By effectively removing the requirement for cell permeability from the probe, the nanostraws expand the toolbox of bioorthogonal probes that can be used to study biological processes on a single, easy-to-use platform.
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Affiliation(s)
- Alexander M Xu
- Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA.,Present address: Chemistry and Chemical Engineering Division, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA, 91106, USA
| | - Derek S Wang
- Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA
| | - Peyton Shieh
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305, USA
| | - Yuhong Cao
- Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA
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22
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Yan H, Hohman JN, Li FH, Jia C, Solis-Ibarra D, Wu B, Dahl JEP, Carlson RMK, Tkachenko BA, Fokin AA, Schreiner PR, Vailionis A, Kim TR, Devereaux TP, Shen ZX, Melosh NA. Hybrid metal-organic chalcogenide nanowires with electrically conductive inorganic core through diamondoid-directed assembly. Nat Mater 2017; 16:349-355. [PMID: 28024157 DOI: 10.1038/nmat4823] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
Controlling inorganic structure and dimensionality through structure-directing agents is a versatile approach for new materials synthesis that has been used extensively for metal-organic frameworks and coordination polymers. However, the lack of 'solid' inorganic cores requires charge transport through single-atom chains and/or organic groups, limiting their electronic properties. Here, we report that strongly interacting diamondoid structure-directing agents guide the growth of hybrid metal-organic chalcogenide nanowires with solid inorganic cores having three-atom cross-sections, representing the smallest possible nanowires. The strong van der Waals attraction between diamondoids overcomes steric repulsion leading to a cis configuration at the active growth front, enabling face-on addition of precursors for nanowire elongation. These nanowires have band-like electronic properties, low effective carrier masses and three orders-of-magnitude conductivity modulation by hole doping. This discovery highlights a previously unexplored regime of structure-directing agents compared with traditional surfactant, block copolymer or metal-organic framework linkers.
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Affiliation(s)
- Hao Yan
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford, California 94305, USA
| | - J Nathan Hohman
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Fei Hua Li
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford, California 94305, USA
| | - Chunjing Jia
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
| | - Diego Solis-Ibarra
- Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Coyoacán, CDMX 04510, México
| | - Bin Wu
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford, California 94305, USA
| | - Jeremy E P Dahl
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
| | - Robert M K Carlson
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
| | - Boryslav A Tkachenko
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany
| | - Andrey A Fokin
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany
| | - Arturas Vailionis
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
| | - Taeho Roy Kim
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford, California 94305, USA
| | - Thomas P Devereaux
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
| | - Zhi-Xun Shen
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
| | - Nicholas A Melosh
- Stanford Institute for Materials and Energy Sciences, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford, California 94305, USA
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23
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Xu AM, Kim SA, Wang DS, Aalipour A, Melosh NA. Temporally resolved direct delivery of second messengers into cells using nanostraws. Lab Chip 2016; 16:2434-2439. [PMID: 27292263 DOI: 10.1039/c6lc00463f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Second messengers are biomolecules with the critical role of conveying information to intracellular targets. They are typically membrane-impermeable and only enter cells through tightly regulated transporters. Current methods for manipulating second messengers in cells require preparation of modified cell lines or significant disruptions in cell function, especially at the cell membrane. Here we demonstrate that 100 nm diameter 'nanostraws' penetrate the cell membrane to directly modulate second messenger concentrations within cells. Nanostraws are hollow vertical nanowires that provide a fluidic conduit into cells to allow time-resolved delivery of the signaling ion Ca(2+) without chemical permeabilization or genetic modification, minimizing cell perturbation. By integrating the nanostraw platform into a microfluidic device, we demonstrate coordinated delivery of Ca(2+) ions into hundreds of cells at the time scale of several seconds with the ability to deliver complex signal patterns, such as oscillations over time. The diffusive nature of nanostraw delivery gives the platform unique versatility, opening the possibility for time-resolved delivery of any freely diffusing molecules.
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Affiliation(s)
- Alexander M Xu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
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24
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Fox CB, Cao Y, Nemeth CL, Chirra HD, Chevalier RW, Xu AM, Melosh NA, Desai TA. Fabrication of Sealed Nanostraw Microdevices for Oral Drug Delivery. ACS Nano 2016; 10:5873-81. [PMID: 27268699 PMCID: PMC5435488 DOI: 10.1021/acsnano.6b00809] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The oral route is preferred for systemic drug administration and provides direct access to diseased tissue of the gastrointestinal (GI) tract. However, many drugs have poor absorption upon oral administration due to damaging enzymatic and pH conditions, mucus and cellular permeation barriers, and limited time for drug dissolution. To overcome these limitations and enhance oral drug absorption, micron-scale devices with planar, asymmetric geometries, termed microdevices, have been designed to adhere to the lining of the GI tract and release drug at high concentrations directly toward GI epithelium. Here we seal microdevices with nanostraw membranes-porous nanostructured biomolecule delivery substrates-to enhance the properties of these devices. We demonstrate that the nanostraws facilitate facile drug loading and tunable drug release, limit the influx of external molecules into the sealed drug reservoir, and increase the adhesion of devices to epithelial tissue. These findings highlight the potential of nanostraw microdevices to enhance the oral absorption of a wide range of therapeutics by binding to the lining of the GI tract, providing prolonged and proximal drug release, and reducing the exposure of their payload to drug-degrading biomolecules.
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Affiliation(s)
- Cade B. Fox
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158, United States
| | - Yuhong Cao
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Cameron L. Nemeth
- Graduate Program in Bioengineering, University of California at Berkeley and San Francisco, UCSF Mission Bay Campus, San Francisco, California 94158, United States
| | - Hariharasudhan D. Chirra
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158, United States
| | - Rachel W. Chevalier
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158, United States
- Department of Pediatrics, Division of Pediatric Gastroenterology, School of Medicine, University of California, San Francisco, California 94158, United States
| | - Alexander M. Xu
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Nicholas A. Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Tejal A. Desai
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158, United States
- Graduate Program in Bioengineering, University of California at Berkeley and San Francisco, UCSF Mission Bay Campus, San Francisco, California 94158, United States
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25
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Narasimha KT, Ge C, Fabbri JD, Clay W, Tkachenko BA, Fokin AA, Schreiner PR, Dahl JE, Carlson RMK, Shen ZX, Melosh NA. Ultralow effective work function surfaces using diamondoid monolayers. Nat Nanotechnol 2016; 11:267-272. [PMID: 26641529 DOI: 10.1038/nnano.2015.277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/26/2015] [Indexed: 06/05/2023]
Abstract
Electron emission is critical for a host of modern fabrication and analysis applications including mass spectrometry, electron imaging and nanopatterning. Here, we report that monolayers of diamondoids effectively confer dramatically enhanced field emission properties to metal surfaces. We attribute the improved emission to a significant reduction of the work function rather than a geometric enhancement. This effect depends on the particular diamondoid isomer, with [121]tetramantane-2-thiol reducing gold's work function from ∼ 5.1 eV to 1.60 ± 0.3 eV, corresponding to an increase in current by a factor of over 13,000. This reduction in work function is the largest reported for any organic species and also the largest for any air-stable compound. This effect was not observed for sp(3)-hybridized alkanes, nor for smaller diamondoid molecules. The magnitude of the enhancement, molecule specificity and elimination of gold metal rearrangement precludes geometric factors as the dominant contribution. Instead, we attribute this effect to the stable radical cation of diamondoids. Our computed enhancement due to a positively charged radical cation was in agreement with the measured work functions to within ± 0.3 eV, suggesting a new paradigm for low-work-function coatings based on the design of nanoparticles with stable radical cations.
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Affiliation(s)
- Karthik Thimmavajjula Narasimha
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Chenhao Ge
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Jason D Fabbri
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - William Clay
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Boryslav A Tkachenko
- Institute of Organic Chemistry, Justus-Liebig University, Giessen, Heinrich-Buff-Ring 17, Giessen 35392, Germany
| | - Andrey A Fokin
- Institute of Organic Chemistry, Justus-Liebig University, Giessen, Heinrich-Buff-Ring 17, Giessen 35392, Germany
- Kiev Polytechnic Institute, pr. Pobedy 37, Kiev 03056, Ukraine
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University, Giessen, Heinrich-Buff-Ring 17, Giessen 35392, Germany
| | - Jeremy E Dahl
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Robert M K Carlson
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Z X Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
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26
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Zhang JL, Ishiwata H, Babinec TM, Radulaski M, Müller K, Lagoudakis KG, Dory C, Dahl J, Edgington R, Soulière V, Ferro G, Fokin AA, Schreiner PR, Shen ZX, Melosh NA, Vučković J. Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers. Nano Lett 2016; 16:212-217. [PMID: 26695059 DOI: 10.1021/acs.nanolett.5b03515] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV(-)) color centers in diamond as quantum emitters. Hybrid diamond-SiC structures are realized by combining the growth of nano- and microdiamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV(-) color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ion-implantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV(-) on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV(-) centers. Scanning confocal photoluminescence measurements reveal optically active SiV(-) lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particular, very narrow line widths and small inhomogeneous broadening of SiV(-) lines from all-diamond nanopillar arrays, which is a critical requirement for quantum computation. At low temperatures (5 K) we observe in these structures the signature typical of SiV(-) centers in bulk diamond, consistent with a double lambda. These results indicate that high quality color centers can be incorporated into nanophotonic structures synthetically with properties equivalent to those in bulk diamond, thereby opening opportunities for applications in classical and quantum information processing.
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Affiliation(s)
- Jingyuan Linda Zhang
- E. L. Ginzton Laboratory, Stanford University , Stanford, California 94305, United States
| | - Hitoshi Ishiwata
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Thomas M Babinec
- E. L. Ginzton Laboratory, Stanford University , Stanford, California 94305, United States
| | - Marina Radulaski
- E. L. Ginzton Laboratory, Stanford University , Stanford, California 94305, United States
| | - Kai Müller
- E. L. Ginzton Laboratory, Stanford University , Stanford, California 94305, United States
| | | | - Constantin Dory
- E. L. Ginzton Laboratory, Stanford University , Stanford, California 94305, United States
| | - Jeremy Dahl
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
| | - Robert Edgington
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
| | - Veronique Soulière
- Laboratoire des Multimateriaux et Interfaces, Université de Lyon , 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
| | - Gabriel Ferro
- Laboratoire des Multimateriaux et Interfaces, Université de Lyon , 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
| | - Andrey A Fokin
- Institute of Organic Chemistry, Justus-Liebig University , Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University , Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - Zhi-Xun Shen
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Nicholas A Melosh
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Jelena Vučković
- E. L. Ginzton Laboratory, Stanford University , Stanford, California 94305, United States
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27
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Abstract
Nanowire (NW) arrays offer opportunities for parallel, nondestructive intracellular access for biomolecule delivery, intracellular recording, and sensing. Spontaneous cell membrane penetration by vertical nanowires is essential for these applications, yet the time- and geometry-dependent penetration process is still poorly understood. In this work, the dynamic NW-cell interface during cell spreading was examined through experimental cell penetration measurements combined with two mechanical models based on substrate adhesion force or cell traction forces. Penetration was determined by comparing the induced tension at a series of given membrane configurations to the critical membrane failure tension. The adhesion model predicts that penetration occurs within a finite window shortly after initial cell contact and adhesion, while the traction model predicts increasing penetration over a longer period. NW penetration rates determined from a cobalt ion delivery assay are compared to the predicted results from the two models. In addition, the effects of NW geometry and cell properties are systematically evaluated to identify the key factors for penetration.
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Affiliation(s)
| | | | - Sneha V Gupta
- UCSF School of Pharmacy, Bioengineering and Therapeutic Sciences, University of California, San Francisco , San Francisco, California 94143, United States
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28
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Yuan H, Chang S, Bargatin I, Wang NC, Riley DC, Wang H, Schwede JW, Provine J, Pop E, Shen ZX, Pianetta PA, Melosh NA, Howe RT. Engineering Ultra-Low Work Function of Graphene. Nano Lett 2015; 15:6475-80. [PMID: 26401728 DOI: 10.1021/acs.nanolett.5b01916] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Low work function materials are critical for energy conversion and electron emission applications. Here, we demonstrate for the first time that an ultralow work function graphene is achieved by combining electrostatic gating with a Cs/O surface coating. A simple device is built from large-area monolayer graphene grown by chemical vapor deposition, transferred onto 20 nm HfO2 on Si, enabling high electric fields capacitive charge accumulation in the graphene. We first observed over 0.7 eV work function change due to electrostatic gating as measured by scanning Kelvin probe force microscopy and confirmed by conductivity measurements. The deposition of Cs/O further reduced the work function, as measured by photoemission in an ultrahigh vacuum environment, which reaches nearly 1 eV, the lowest reported to date for a conductive, nondiamond material.
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Affiliation(s)
| | | | - Igor Bargatin
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | | | | | | | | | | | | | | | - Piero A Pianetta
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, MS31, Menlo Park, California 94205, United States
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29
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Angle MR, Wang A, Thomas A, Schaefer AT, Melosh NA. Penetration of cell membranes and synthetic lipid bilayers by nanoprobes. Biophys J 2015; 107:2091-100. [PMID: 25418094 DOI: 10.1016/j.bpj.2014.09.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/08/2014] [Accepted: 09/16/2014] [Indexed: 11/28/2022] Open
Abstract
Nanoscale devices have been proposed as tools for measuring and controlling intracellular activity by providing electrical and/or chemical access to the cytosol. Unfortunately, nanostructures with diameters of 50-500 nm do not readily penetrate the cell membrane, and rationally optimizing nanoprobes for cell penetration requires real-time characterization methods that are capable of following the process of membrane penetration with nanometer resolution. Although extensive work has examined the rupture of supported synthetic lipid bilayers, little is known about the applicability of these model systems to living cell membranes with complex lipid compositions, cytoskeletal attachment, and membrane proteins. Here, we describe atomic force microscopy (AFM) membrane penetration experiments in two parallel systems: live HEK293 cells and stacks of synthetic lipid bilayers. By using the same probes in both systems, we were able to clearly identify membrane penetration in synthetic bilayers and compare these events with putative membrane penetration events in cells. We examined membrane penetration forces for three tip geometries and 18 chemical modifications of the probe surface, and in all cases the median forces required to penetrate cellular and synthetic lipid bilayers with nanoprobes were greater than 1 nN. The penetration force was sensitive to the probe's sharpness, but not its surface chemistry, and the force did not depend on cell surface or cytoskeletal properties, with cells and lipid stacks yielding similar forces. This systematic assessment of penetration under various mechanical and chemical conditions provides insights into nanoprobe-cell interactions and informs the design of future intracellular nanoprobes.
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Affiliation(s)
- Matthew R Angle
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Andrew Wang
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Aman Thomas
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Andreas T Schaefer
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, California.
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30
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Abstract
Neuroscience would be revolutionized by a technique to measure intracellular electrical potentials that would not disrupt cellular physiology and could be massively parallelized. Though such a technology does not yet exist, the technical hurdles for fabricating minimally disruptive, solid-state electrical probes have arguably been overcome in the field of nanotechnology. Nanoscale devices can be patterned with features on the same length scale as biological components, and several groups have demonstrated that nanoscale electrical probes can measure the transmembrane potential of electrogenic cells. Developing these nascent technologies into robust intracellular recording tools will now require a better understanding of device-cell interactions, especially the membrane-inorganic interface. Here we review the state-of-the art in nanobioelectronics, emphasizing the characterization and design of stable interfaces between nanoscale devices and cells.
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Affiliation(s)
- Matthew R Angle
- Department of Materials Science and Engineering, Stanford University, CA, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, CA, USA
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, CA, USA; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
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31
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Abstract
Synthesis of hierarchical “spiky” nanoparticles covered with stiff nanowires for biological cellular interface and engulfment.
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Affiliation(s)
- Xi Xie
- Department of Materials Science and Engineering
- Stanford University
- Stanford
- USA
- David H. Koch Institute for Integrative Cancer Research
| | - Nicholas A. Melosh
- Department of Materials Science and Engineering
- Stanford University
- Stanford
- USA
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32
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Abstract
Diamondoids are small hydrocarbon molecules which have the same rigid cage structure as bulk diamond. They can be considered the smallest nanoparticles of diamond. They exhibit a mixture of properties inherited from bulk cubic diamond as well as a number of unique properties related to their size and structure. Diamondoids with different sizes and shapes can be separated and purified, enabling detailed studies of the effects of size and structure on the diamondoids' properties and also allowing the creation of chemically functionalized diamondoids which can be used to create new materials. Most notable among these new materials are self-assembled monolayers of diamondoid-thiols, which exhibit a number of unique electron emission properties.
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Affiliation(s)
- W A Clay
- Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, CA 94305
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Aalipour A, Xu AM, Leal-Ortiz S, Garner CC, Melosh NA. Plasma membrane and actin cytoskeleton as synergistic barriers to nanowire cell penetration. Langmuir 2014; 30:12362-7. [PMID: 25244597 DOI: 10.1021/la502273f] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nanowires are a rapidly emerging platform for manipulation of and material delivery directly into the cell cytosol. These high aspect ratio structures can breach the lipid membrane; however, the yield of penetrant structures is low, and the mechanism is largely unknown. In particular, some nanostructures appear to defeat the membrane transiently, while others can retain long-term access. Here, we examine if local dissolution of the lipid membrane, actin cytoskeleton, or both can enhance nanowire penetration. It is possible that, during cell contact, membrane rupture occurs; however, if the nanostructures do not penetrate the cytoskeleton, the membrane may reclose over a relatively short time frame. We show with quantitative analysis of the number of penetrating nanowires that the lipid bilayer and actin cytoskeleton are synergistic barriers to nanowire cell access, yet chemical poration through both is still insufficient to increase long-term access for adhered cells.
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Affiliation(s)
- Amin Aalipour
- Department of Materials Science and Engineering, Stanford University , 476 Lomita Mall, Stanford, California 94305, United States
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VanDersarl JJ, Mehraeen S, Schoen AP, Heilshorn SC, Spakowitz AJ, Melosh NA. Rheology and simulation of 2-dimensional clathrin protein network assembly. Soft Matter 2014; 10:6219-6227. [PMID: 25012232 DOI: 10.1039/c4sm00025k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Clathrin is a three-legged protein complex that assembles into lattice structures on the cell membrane and transforms into fullerene-like cages during endocytosis. This dynamic structural flexibility makes clathrin an attractive building block for guided assembly. The assembly dynamics and the mechanical properties of clathrin protein lattices are studied using rheological measurements and theoretical modelling in an effort to better understand two dynamic processes: protein adsorption to the interface and assembly into a network. We find that percolation models for protein network formation are insufficient to describe clathrin network formation, but with Monte Carlo simulations we can describe the dynamics of network formation very well. Insights from this work can be used to design new bio-inspired nano-assembly systems.
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Affiliation(s)
- Jules J VanDersarl
- Materials Science & Engineering, Stanford University, Stanford, CA 94305, USA.
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Verma P, Mager MD, Melosh NA. Rough-smooth-rough dynamic interface growth in supported lipid bilayers. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 89:012404. [PMID: 24580234 DOI: 10.1103/physreve.89.012404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Indexed: 06/03/2023]
Abstract
The role of lipid bilayer viscoelasticity and the substrate-bilayer interactions on the spreading behavior of supported phospholipid bilayer membranes is studied using fluorescence microscopy. Unlike the monotonic roughening observed on silica or in other dynamic interface growth systems, a unique rough-smooth-rough (RSR) interface transition occurred on chromium oxide with a roughness exponent of 0.45 ± 0.04. This RSR transition is attributed to the elasticity of the lipid bilayer which is initially under compression due to surface interactions, and is well approximated by adding an elastic term to the quenched noise Edwards-Wilkinson equation. A phase diagram depicting the conditions necessary to observe RSR transitions in dynamic interface systems is derived, revealing the classes of dynamically evolving systems is broader than previously thought, and the viscoelastic nature of the lipid bilayer may play a role in supported membrane behavior.
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Affiliation(s)
- Piyush Verma
- Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA
| | - Morgan D Mager
- Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA
| | - N A Melosh
- Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA
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Littau KA, Sahasrabuddhe K, Barfield D, Yuan H, Shen ZX, Howe RT, Melosh NA. Microbead-separated thermionic energy converter with enhanced emission current. Phys Chem Chem Phys 2013; 15:14442-6. [PMID: 23881241 DOI: 10.1039/c3cp52895b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The efficiency of thermionic energy converters is a strong function of the inter-electrode separation due to space-charge limitations. Here we demonstrate vacuum thermionic energy converters constructed using barium dispenser cathodes and thin film tungsten anodes, separated by size specific alumina microbeads for simple device fabrication and inter-electrode gap control. The current and device efficiency at the maximum power point are strongly dependent on the inter-electrode gap, with a maximum device efficiency of 0.61% observed for a gap on the order of 5 μm. Paths to further reductions in space charge and improved anode work function are outlined with potential for over an order of magnitude improvement in output power and efficiency.
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Xie X, Xu AM, Leal-Ortiz S, Cao Y, Garner CC, Melosh NA. Nanostraw-electroporation system for highly efficient intracellular delivery and transfection. ACS Nano 2013; 7:4351-8. [PMID: 23597131 DOI: 10.1021/nn400874a] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nondestructive introduction of genes, proteins, and small molecules into mammalian cells with high efficiency is a challenging, yet critical, process. Here we demonstrate a simple nanoelectroporation platform to achieve highly efficient molecular delivery and high transfection yields with excellent uniformity and cell viability. The system is built on alumina nanostraws extending from a track-etched membrane, forming an array of hollow nanowires connected to an underlying microfluidic channel. Cellular engulfment of the nanostraws provides an intimate contact, significantly reducing the necessary electroporation voltage and increasing homogeneity over a large area. Biomolecule delivery is achieved by diffusion through the nanostraws and enhanced by electrophoresis during pulsing. The system was demonstrated to offer excellent spatial, temporal, and dose control for delivery, as well as providing high-yield cotransfection and sequential transfection.
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Affiliation(s)
- Xi Xie
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
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Wang F, Melosh NA. Power-independent wavelength determination by hot carrier collection in metal-insulator-metal devices. Nat Commun 2013; 4:1711. [DOI: 10.1038/ncomms2728] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 03/08/2013] [Indexed: 11/09/2022] Open
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Abstract
Direct access into cells' interiors is essential for biomolecular delivery, gene transfection, and electrical recordings yet is challenging due to the cell membrane barrier. Recently, molecular delivery using vertical nanowires (NWs) has been demonstrated for introducing biomolecules into a large number of cells in parallel. However, the microscopic understanding of how and when the nanowires penetrate cell membranes is still lacking, and the degree to which actual membrane penetration occurs is controversial. Here we present results from a mechanical continuum model of elastic cell membrane penetration through two mechanisms, namely through "impaling" as cells land onto a bed of nanowires, and through "adhesion-mediated" penetration, which occurs as cells spread on the substrate and generate adhesion force. Our results reveal that penetration is much more effective through the adhesion mechanism, with NW geometry and cell stiffness being critically important. Stiffer cells have higher penetration efficiency, but are more sensitive to NW geometry. These results provide a guide to designing nanowires for applications in cell membrane penetration.
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Affiliation(s)
- Xi Xie
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
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Ye X, Melas-Kyriazi J, Feng ZA, Melosh NA, Chueh WC. A semiconductor/mixed ion and electron conductor heterojunction for elevated-temperature water splitting. Phys Chem Chem Phys 2013; 15:15459-69. [DOI: 10.1039/c3cp52536h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Nanomaterials are promising candidates to improve the delivery efficiency and control of active agents such as DNA or drugs directly into cells. Here we demonstrate cell-culture platforms of nanotemplated "nanostraws" that pierce the cell membrane, providing a permanent fluidic pipeline into the cell for direct cytosolic access. Conventional polymeric track-etch cell culture membranes are alumina coated and etched to produce fields of nanostraws with controllable diameter, thickness, and height. Small molecules and ions were successfully transported into the cytosol with 40 and 70% efficiency, respectively, while GFP plasmids were successfully delivered and expressed. These platforms open the way for active, reproducible delivery of a wide variety of species into cells without endocytosis.
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Affiliation(s)
- Jules J VanDersarl
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
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Lee HJ, Park KK, Kupnik M, Melosh NA, Khuri-Yakub BT. Mesoporous thin-film on highly-sensitive resonant chemical sensor for relative humidity and CO2 detection. Anal Chem 2012; 84:3063-6. [PMID: 22372606 DOI: 10.1021/ac300225c] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Distributed sensing of gas-phase chemicals is a promising application for mesoporous materials when combined with highly sensitive miniaturized gas sensors. We present a direct application of a mesoporous silica thin film on a highly sensitive miniaturized resonant chemical sensor with a mass sensitivity at the zeptogram scale for relative humidity and CO(2) detection. Using mesoporous silica thin-film, we report one of the lowest volume resolutions and a sensitive detection of 5.1 × 10(-4)% RH/Hz to water vapor in N(2), which is 70 times higher than a device with a nontemplated silica layer. In addition, a mesoporous thin-film that is functionalized with an amino-group is directly applied on the resonant sensor, which exhibits a volume sensitivity of 1.6 × 10(-4)%/Hz and a volume resolution of 1.82 × 10(-4)% to CO(2) in N(2).
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46
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Xie X, Melosh NA. Mechanical Model of Cell Membrane Penetration by Vertical Nanowires. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.1116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Abstract
Conversion of light into direct current is important for applications ranging from energy conversion to photodetection, yet often challenging over broad photon frequencies. Here we show a new architecture based on surface plasmon excitation within a metal-insulator-metal device that produces power based on spatial confinement of electron excitation through plasmon absorption. Plasmons excited in the upper metal are absorbed, creating a high concentration of hot electrons which can inject above or tunnel through the thin insulating barrier, producing current. The theoretical power conversion efficiency enhancement achieved can be almost 40 times larger than that of direct illumination while utilizing a broad spectrum of IR to visible wavelengths. Here we present both theoretical estimates of the power conversion efficiency and experimental device measurements, which show clear rectification and power conversion behavior.
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Affiliation(s)
- Fuming Wang
- Department of Materials Science and Engingeering, Stanford University, Stanford, California 94305, United States
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48
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Abstract
Controlled chemical delivery in microfluidic cell culture devices often relies on slowly evolving diffusive gradients, as the spatial and temporal control provided by fluid flow results in significant cell-perturbation. In this paper we introduce a microfluidic device architecture that allows for rapid spatial and temporal soluble signal delivery over large cell culture areas without fluid flow over the cells. In these devices the cell culture well is divided from a microfluidic channel located directly underneath the chamber by a nanoporous membrane. This configuration requires chemical signals in the microchannel to only diffuse through the thin membrane into large cell culture area, rather than diffuse in from the sides. The spatial chemical pattern within the microfluidic channel was rapidly transferred to the cell culture area with good fidelity through diffusion. The cellular temporal response to a step-function signal showed that dye reached the cell culture surface within 45 s, and achieved a static concentration in under 6 min. Chemical pulses of less than one minute were possible by temporally alternating the signal within the microfluidic channel, enabling rapid flow-free chemical microenvironment control for large cell culture areas.
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Affiliation(s)
- Jules J VanDersarl
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
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Abstract
Nanoscale patterning of hydrophobic bands on otherwise hydrophilic surfaces allows integration of inorganic structures through biological membranes, reminiscent of transmembrane proteins. Here we show that a set of innate molecular properties of the self-assembling hydrophobic band determine the resulting interface stability. Surprisingly, hydrophobicity is found to be a secondary factor with monolayer crystallinity the major determinate of interface strength. These results begin to establish guidelines for seamless bioinorganic integration of nanoscale probes with lipid membranes.
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Affiliation(s)
- Benjamin D Almquist
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
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50
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Hager-Barnard EA, Almquist BD, Melosh NA. AFM Force Spectroscopy on TAT Membrane Penetration. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.2899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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