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Das A, Santhosh S, Giridhar M, Behr J, Michel T, Schaudy E, Ibáñez-Redín G, Lietard J, Somoza MM. Dipodal Silanes Greatly Stabilize Glass Surface Functionalization for DNA Microarray Synthesis and High-Throughput Biological Assays. Anal Chem 2023; 95:15384-15393. [PMID: 37801728 PMCID: PMC10586054 DOI: 10.1021/acs.analchem.3c03399] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023]
Abstract
Glass is by far the most common substrate for biomolecular arrays, including high-throughput sequencing flow cells and microarrays. The native glass hydroxyl surface is modified by using silane chemistry to provide appropriate functional groups and reactivities for either in situ synthesis or surface immobilization of biologically or chemically synthesized biomolecules. These arrays, typically of oligonucleotides or peptides, are then subjected to long incubation times in warm aqueous buffers prior to fluorescence readout. Under these conditions, the siloxy bonds to the glass are susceptible to hydrolysis, resulting in significant loss of biomolecules and concomitant loss of signal from the assay. Here, we demonstrate that functionalization of glass surfaces with dipodal silanes results in greatly improved stability compared to equivalent functionalization with standard monopodal silanes. Using photolithographic in situ synthesis of DNA, we show that dipodal silanes are compatible with phosphoramidite chemistry and that hybridization performed on the resulting arrays provides greatly improved signal and signal-to-noise ratios compared with surfaces functionalized with monopodal silanes.
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Affiliation(s)
- Arya Das
- Technical
University of Munich, Germany, TUM School
of Natural Sciences, Boltzmannstraße 10, 85748 Garching, Germany
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, 85354 Freising, Germany
| | - Santra Santhosh
- Technical
University of Munich, Germany, TUM School
of Natural Sciences, Boltzmannstraße 10, 85748 Garching, Germany
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, 85354 Freising, Germany
| | - Maya Giridhar
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, 85354 Freising, Germany
| | - Jürgen Behr
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, 85354 Freising, Germany
| | - Timm Michel
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, 85354 Freising, Germany
- Technical
University of Munich, Germany, TUM School
of Life Sciences, Alte
Akademie 8, 85354 Freising, Germany
| | - Erika Schaudy
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Gisela Ibáñez-Redín
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Jory Lietard
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Mark M. Somoza
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, 85354 Freising, Germany
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Chair
of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
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2
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Purohit P, Bhatt A, Mittal RK, Abdellattif MH, Farghaly TA. Polymer Grafting and its chemical reactions. Front Bioeng Biotechnol 2023; 10:1044927. [PMID: 36714621 PMCID: PMC9874337 DOI: 10.3389/fbioe.2022.1044927] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/12/2022] [Indexed: 01/13/2023] Open
Abstract
Polymer grafting is a technique to improve the morphology, chemical, and physical properties of the polymer. This technique has the potential to improve the existing conduction and properties of polymers other than charge transport; as a result, it enhances the solubility, nano-dimensional morphology, biocompatibility, bio-communication, and other property of parent polymer. A polymer's physicochemical properties can be modified even further by creating a copolymer with another polymer or by grafting. Here in the various chemical approaches for polymer grafting, like free radical, click reaction, amide formation, and alkylation have been discussed with their importance, moreover the process and its importance are covered comprehensively with their scientific explanation. The present review also covers the effectiveness of the graft-to approaches and its application in various fields, which will give reader a glimpse about polymer grafting and its uses.
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Affiliation(s)
- Priyank Purohit
- School of Pharmacy, Graphic Era Hill University, Dehradun, India,*Correspondence: Priyank Purohit, ,
| | - Akanksha Bhatt
- School of Pharmacy, Graphic Era Hill University, Dehradun, India
| | | | | | - Thoraya A. Farghaly
- Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia
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3
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Bachman B, Zhu D, Bandy J, Zhang L, Hamers RJ. Detection of Aqueous Solvated Electrons Produced by Photoemission from Solids Using Transient Absorption Measurements. ACS MEASUREMENT SCIENCE AU 2022; 2:46-56. [PMID: 36785590 PMCID: PMC9838729 DOI: 10.1021/acsmeasuresciau.1c00025] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Solvated electrons in water have long been of interest to chemists. While readily produced using intense multiphoton excitation of water and/or irradiation with high-energy particles, the possible role of solvated electrons in electrochemical and photoelectrochemical reactions at electrodes has been controversial. Recent studies showed that excitation of electrons to the conduction band of diamond leads to barrier-free emission of electrons into water. While these electrons can be inferred from the reactions they induce, direct detection by transient absorption measurements provides more direct evidence. Here, we present studies demonstrating direct detection of solvated electrons produced at diamond electrode surfaces and the influence of electrochemical potential and solution-phase electron scavengers. We further present a more detailed analysis of experimental conditions needed to detect solvated electrons emitted from diamond and other solid materials through transient optical absorption measurements.
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4
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Suni II. Substrate Materials for Biomolecular Immobilization within Electrochemical Biosensors. BIOSENSORS 2021; 11:239. [PMID: 34356710 PMCID: PMC8301891 DOI: 10.3390/bios11070239] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/01/2021] [Accepted: 07/08/2021] [Indexed: 01/17/2023]
Abstract
Electrochemical biosensors have potential applications for agriculture, food safety, environmental monitoring, sports medicine, biomedicine, and other fields. One of the primary challenges in this field is the immobilization of biomolecular probes atop a solid substrate material with adequate stability, storage lifetime, and reproducibility. This review summarizes the current state of the art for covalent bonding of biomolecules onto solid substrate materials. Early research focused on the use of Au electrodes, with immobilization of biomolecules through ω-functionalized Au-thiol self-assembled monolayers (SAMs), but stability is usually inadequate due to the weak Au-S bond strength. Other noble substrates such as C, Pt, and Si have also been studied. While their nobility has the advantage of ensuring biocompatibility, it also has the disadvantage of making them relatively unreactive towards covalent bond formation. With the exception of Sn-doped In2O3 (indium tin oxide, ITO), most metal oxides are not electrically conductive enough for use within electrochemical biosensors. Recent research has focused on transition metal dichalcogenides (TMDs) such as MoS2 and on electrically conductive polymers such as polyaniline, polypyrrole, and polythiophene. In addition, the deposition of functionalized thin films from aryldiazonium cations has attracted significant attention as a substrate-independent method for biofunctionalization.
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Affiliation(s)
- Ian Ivar Suni
- Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, USA; ; Tel.: +1-618-453-7822
- School of Chemistry and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
- School of Mechanical, Aerospace and Materials Engineering, Southern Illinois University, Carbondale, IL 62901, USA
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5
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Henke AH, Saunders TP, Pedersen JA, Hamers RJ. Enhancing Electrochemical Efficiency of Hydroxyl Radical Formation on Diamond Electrodes by Functionalization with Hydrophobic Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:2153-2163. [PMID: 30550713 DOI: 10.1021/acs.langmuir.8b04030] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Electrochemical formation of high-energy species such as hydroxyl radicals in aqueous media is inefficient because oxidation of H2O to form O2 is a more thermodynamically favorable reaction. Boron-doped diamond (BDD) is widely used as an electrode material for generating •OH radicals because it has a very large kinetic overpotential for O2 production, thus increasing electrochemical efficiency for •OH production. Yet, the underlying mechanisms of O2 and •OH production at diamond electrodes are not well understood. We demonstrate that boron-doped diamond surfaces functionalized with hydrophobic, polyfluorinated molecular ligands (PF-BDD) have significantly higher electrochemical efficiency for •OH production compared with hydrogen-terminated (H-BDD), oxidized (O-BDD), or poly(ethylene ether)-functionalized (E-BDD) boron-doped diamond samples. Our measurements show that •OH production is nearly independent of surface functionalization and pH (pH = 7.4 vs 9.2), indicating that •OH is produced by oxidation of H2O in an outer-sphere electron-transfer process. In contrast, the total electrochemical current, which primarily produces O2, differs strongly between samples with different surface functionalizations, indicating an inner-sphere electron-transfer process. X-ray photoelectron spectroscopy measurements show that although both H-BDD and PF-BDD electrodes are oxidized over time, PF-BDD showed longer stability (≈24 h of use) than H-BDD. This work demonstrates that increasing surface hydrophobicity using perfluorinated ligands selectively inhibits inner-sphere oxidation to O2 and therefore provides a pathway to increased efficiency for formation of •OH via an outer-sphere process. The use of hydrophobic electrodes may be a general approach to increasing selectivity toward outer-sphere electron-transfer processes in aqueous media.
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6
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Ghosh D, Febriansyah B, Gupta D, Ng LKS, Xi S, Du Y, Baikie T, Dong Z, Soo HS. Hybrid Nanomaterials with Single-Site Catalysts by Spatially Controllable Immobilization of Nickel Complexes via Photoclick Chemistry for Alkene Epoxidation. ACS NANO 2018; 12:5903-5912. [PMID: 29775278 DOI: 10.1021/acsnano.8b02118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Catalyst deactivation is a persistent problem not only for the scientific community but also in industry. Isolated single-site heterogeneous catalysts have shown great promise to overcome these problems. Here, a versatile anchoring strategy for molecular complex immobilization on a broad range of semiconducting or insulating metal oxide ( e. g., titanium dioxide, mesoporous silica, cerium oxide, and tungsten oxide) nanoparticles to synthesize isolated single-site catalysts has been studied systematically. An oxidatively stable anchoring group, maleimide, is shown to form covalent linkages with surface hydroxyl functionalities of metal oxide nanoparticles by photoclick chemistry. The nanocomposites have been thoroughly characterized by techniques including UV-visible diffuse reflectance spectroscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and X-ray absorption spectroscopy (XAS). The IR spectroscopic studies confirm the covalent linkages between the maleimide group and surface hydroxyl functionalities of the oxide nanoparticles. The hybrid nanomaterials function as highly efficient catalysts for essentially quantitative oxidations of terminal and internal alkenes and show molecular catalyst product selectivities even in more eco-friendly solvents. XAS studies verify the robustness of the catalysts after several catalytic cycles. We have applied the photoclick anchoring methodology to precisely control the deposition of a luminescent variant of our catalyst on the metal oxide nanoparticles. Overall, we demonstrate a general approach to use irradiation to anchor molecular complexes on oxide nanoparticles to create recyclable, hybrid, single-site catalysts that function with high selectivity in a broad range of solvents. We have achieved a facile, spatially and temporally controllable photoclick method that can potentially be extended to other ligands, catalysts, functional molecules, and surfaces.
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Affiliation(s)
- Dwaipayan Ghosh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , Singapore 637371 , Singapore
| | - Benny Febriansyah
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , Singapore 637371 , Singapore
| | - Disha Gupta
- School of Materials Science and Engineering , 50 Nanyang Avenue , Nanyang Technological University , Singapore 639798 , Singapore
| | - Leonard Kia-Sheun Ng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , Singapore 637371 , Singapore
- Energy Research Institute@NTU (ERI@N) , Nanyang Technological University, Interdisciplinary Graduate School , Research Techno Plaza , Singapore 637553 , Singapore
| | - Shibo Xi
- Institute of Chemical and Engineering Sciences A*STAR , 1 Pesek Road , Singapore 627833 , Singapore
| | - Yonghua Du
- Institute of Chemical and Engineering Sciences A*STAR , 1 Pesek Road , Singapore 627833 , Singapore
| | - Tom Baikie
- Energy Research Institute@NTU (ERI@N), Nanyang Technological University , Research Techno Plaza , Singapore 637553 , Singapore
| | - ZhiLi Dong
- School of Materials Science and Engineering , 50 Nanyang Avenue , Nanyang Technological University , Singapore 639798 , Singapore
| | - Han Sen Soo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , Singapore 637371 , Singapore
- Solar Fuels Laboratory , Nanyang Technological University , 50 Nanyang Avenue , Singapore 639798 , Singapore
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7
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Brunet M, Aureau D, Guillemot F, Etcheberry A, Ozanam F, Gouget-Laemmel AC. The critical role of wavelength in the UV-activated grafting of 1-alkene onto silicon and silicon nitride Si xN 4 surfaces. Chem Commun (Camb) 2018; 54:7167-7170. [DOI: 10.1039/c8cc03207f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The wavelength used during photochemical grafting of alkene onto silicon related surfaces influences molecular surface coverage.
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Affiliation(s)
- M. Brunet
- Physique de la Matière Condensée
- Ecole Polytechnlque
- CNRS
- Université Paris Saclay
- 91128 Palaiseau
| | - D. Aureau
- Institut Lavoisier de Versailles
- UMR 8180 UVSQ-CNRS
- Université Paris Saclay
- Versailles
- France
| | | | - A. Etcheberry
- Institut Lavoisier de Versailles
- UMR 8180 UVSQ-CNRS
- Université Paris Saclay
- Versailles
- France
| | - F. Ozanam
- Physique de la Matière Condensée
- Ecole Polytechnlque
- CNRS
- Université Paris Saclay
- 91128 Palaiseau
| | - A. C. Gouget-Laemmel
- Physique de la Matière Condensée
- Ecole Polytechnlque
- CNRS
- Université Paris Saclay
- 91128 Palaiseau
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8
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Raymakers J, Krysova H, Artemenko A, Čermák J, Nicley SS, Verstappen P, Gielen S, Kromka A, Haenen K, Kavan L, Maes W, Rezek B. Functionalization of boron-doped diamond with a push–pull chromophore via Sonogashira and CuAAC chemistry. RSC Adv 2018; 8:33276-33290. [PMID: 35548149 PMCID: PMC9086440 DOI: 10.1039/c8ra07545j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 09/18/2018] [Indexed: 11/21/2022] Open
Abstract
Functionalization of boron-doped diamond with a push–pull chromophore via Sonogashira cross-coupling affords better photovoltaic performances as compared to functionalization via CuAAC.
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9
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Robinson ME, Ng JD, Zhang H, Buchman JT, Shenderova OA, Haynes CL, Ma Z, Goldsmith RH, Hamers RJ. Optically Detected Magnetic Resonance for Selective Imaging of Diamond Nanoparticles. Anal Chem 2017; 90:769-776. [PMID: 29131578 DOI: 10.1021/acs.analchem.7b03157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
While there is great interest in understanding the fate and transport of nanomaterials in the environment and in biological systems, the detection of nanomaterials in complex matrices by fluorescence methods is complicated by photodegradation, blinking, and the presence of natural organic material and other fluorescent background signals that hamper detection of fluorescent nanomaterials of interest. Optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers in diamond nanoparticles provides a pathway toward background-free fluorescence measurements, as the application of a resonant microwave field can selectively modulate the intensity from NV centers in nanodiamonds of various diameters in complex materials systems using on-resonance and off-resonance microwave fields. This work represents the first investigation showing how nanoparticle diameter impacts the NV center lifetime and thereby directly impacts the accessible contrast and signal-to-noise ratio when using ODMR to achieve background-free imaging of NV-nanodiamonds in the presence of interfering fluorophores. These results provide new insights that will guide the choice of optimum nanoparticle size and methodology for background-free imaging and sensing applications, while also providing a model system to explore the fate and transport of nanomaterials in the environment.
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Affiliation(s)
- Margaret E Robinson
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - James D Ng
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Huilong Zhang
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison , 3445 Engineering Hall, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Joseph T Buchman
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Olga A Shenderova
- Adámas Nanotechnologies , 8100 Brownleigh Drive, Raleigh, North Carolina 27617, United States
| | - Christy L Haynes
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Zhenqiang Ma
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison , 3445 Engineering Hall, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Randall H Goldsmith
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Robert J Hamers
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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10
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Porosa L, Deng H, Bedard J, Lough AJ, Wolfaardt G, Foucher DA. A C18Quaternary Ammonium Library. ChemistrySelect 2016. [DOI: 10.1002/slct.201601540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lukasz Porosa
- Department of Chemistry and Biology; Ryerson University; 350 Victoria Street Toronto, ON Canada M5B 2 K3
| | - Hellen Deng
- Department of Chemistry and Biology; Ryerson University; 350 Victoria Street Toronto, ON Canada M5B 2 K3
| | - Joseph Bedard
- Department of Chemistry and Biology; Ryerson University; 350 Victoria Street Toronto, ON Canada M5B 2 K3
| | - Alan J. Lough
- Department of Chemistry; University of Toronto; 80 St. George Street Toronto Ontario Canada M5S-3H6
| | - Gideon Wolfaardt
- Department of Chemistry and Biology; Ryerson University; 350 Victoria Street Toronto, ON Canada M5B 2 K3
| | - Daniel A. Foucher
- Department of Chemistry and Biology; Ryerson University; 350 Victoria Street Toronto, ON Canada M5B 2 K3
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11
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Berisha A, Chehimi M, Pinson J, Podvorica F. Electrode Surface Modification Using Diazonium Salts. ELECTROANALYTICAL CHEMISTRY: A SERIES OF ADVANCES 2015. [DOI: 10.1201/b19196-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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12
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Lockett MR, Smith LM. Carbon Substrates: A Stable Foundation for Biomolecular Arrays. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2015; 8:263-285. [PMID: 26048550 PMCID: PMC6287745 DOI: 10.1146/annurev-anchem-071114-040146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Since their advent in the early 1990s, microarray technologies have developed into a powerful and ubiquitous platform for biomolecular analysis. Microarrays consist of three major elements: the substrate upon which they are constructed, the chemistry employed to attach biomolecules, and the biomolecules themselves. Although glass substrates and silane-based attachment chemistries are used for the vast majority of current microarray platforms, these materials suffer from severe limitations in stability, due to hydrolysis of both the substrate material itself and of the silyl ether linkages employed for attachment. These limitations in stability compromise assay performance and render impossible many potential microarray applications. We describe here a suite of alternative carbon-based substrates and associated attachment chemistries for microarray fabrication. The substrates themselves, as well as the carbon-carbon bond-based attachment chemistries, offer greatly increased chemical stability, enabling a myriad of novel applications.
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Affiliation(s)
- Matthew R Lockett
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599;
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13
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Gallant BM, Gu XW, Chen DZ, Greer JR, Lewis NS. Tailoring of interfacial mechanical shear strength by surface chemical modification of silicon microwires embedded in Nafion membranes. ACS NANO 2015; 9:5143-5153. [PMID: 25872455 DOI: 10.1021/acsnano.5b00468] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The interfacial shear strength between Si microwires and a Nafion membrane has been tailored through surface functionalization of the Si. Acidic (-COOH-terminated) or basic (-NH2-terminated) surface-bound functionality was introduced by hydrosilylation reactions to probe the interactions between the functionalized Si microwires and hydrophilic ionically charged sites in the Nafion polymeric side chains. Surfaces functionalized with SiOx, Si-H, or Si-CH3 were also synthesized and investigated. The interfacial shear strength between the functionalized Si microwire surfaces and the Nafion matrix was quantified by uniaxial wire pull-out experiments in an in situ nanomechanical instrument that allowed simultaneous collection of mechanical data and visualization of the deformation process. In this process, an axial load was applied to the custom-shaped top portions of individual wires until debonding occurred from the Nafion matrix. The shear strength obtained from the nanomechanical measurements correlated with the chemical bond strength and the functionalization density of the molecular layer, with values ranging from 7 MPa for Si-CH3 surfaces to ∼16-20 MPa for oxygen-containing surface functionalities. Hence surface chemical control can be used to influence the mechanical adhesion forces at a Si-Nafion interface.
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Affiliation(s)
- Betar M Gallant
- †Division of Chemistry and Chemical Engineering, ‡Division of Engineering and Applied Sciences, §The Kavli Nanoscience Institute at Caltech, and ∥The Beckman Institute at Caltech, California Institute of Technology, Pasadena, California 91125, United States
| | - X Wendy Gu
- †Division of Chemistry and Chemical Engineering, ‡Division of Engineering and Applied Sciences, §The Kavli Nanoscience Institute at Caltech, and ∥The Beckman Institute at Caltech, California Institute of Technology, Pasadena, California 91125, United States
| | - David Z Chen
- †Division of Chemistry and Chemical Engineering, ‡Division of Engineering and Applied Sciences, §The Kavli Nanoscience Institute at Caltech, and ∥The Beckman Institute at Caltech, California Institute of Technology, Pasadena, California 91125, United States
| | - Julia R Greer
- †Division of Chemistry and Chemical Engineering, ‡Division of Engineering and Applied Sciences, §The Kavli Nanoscience Institute at Caltech, and ∥The Beckman Institute at Caltech, California Institute of Technology, Pasadena, California 91125, United States
| | - Nathan S Lewis
- †Division of Chemistry and Chemical Engineering, ‡Division of Engineering and Applied Sciences, §The Kavli Nanoscience Institute at Caltech, and ∥The Beckman Institute at Caltech, California Institute of Technology, Pasadena, California 91125, United States
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14
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Rahsepar FR, Zhang L, Farkhondeh H, Leung KT. Biofunctionalization of Si(111)7×7 by “Renewable” l-Cysteine Transitional Layer. J Am Chem Soc 2014; 136:16909-18. [DOI: 10.1021/ja509264t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Fatemeh R. Rahsepar
- WATLab and Department of
Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Lei Zhang
- WATLab and Department of
Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Hanieh Farkhondeh
- WATLab and Department of
Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - K. T. Leung
- WATLab and Department of
Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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15
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Yeap WS, Liu X, Bevk D, Pasquarelli A, Lutsen L, Fahlman M, Maes W, Haenen K. Functionalization of boron-doped nanocrystalline diamond with N3 dye molecules. ACS APPLIED MATERIALS & INTERFACES 2014; 6:10322-10329. [PMID: 24915549 DOI: 10.1021/am501783b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
N3 dye molecules [cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(II)] are covalently attached to boron-doped nanocrystalline diamond (B:NCD) thin films through a combination of coupling chemistries, i.e., diazonium, Suzuki, and EDC-NHS. X-ray and ultraviolet photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy are used to verify the covalent bonding of the dye on the B:NCD surface (compared to a hydrogen-terminated reference). The spectroscopic results confirm the presence of a dense N3 chromophore layer, and the positions of the frontier orbitals of the dye relative to the band edge of the B:NCD thin film are inferred as well. Proof-of-concept photoelectrochemical measurements show a strong increase in the photocurrent compared to non-dye-functionalized B:NCD films. This study opens up the possibility of applying N3-sensitized B:NCD thin films as hole conductors in dye-sensitized solar cells.
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Affiliation(s)
- W S Yeap
- Institute for Materials Research (IMO), Hasselt University , B-3590 Diepenbeek, Belgium
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16
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Yeap WS, Murib MS, Cuypers W, Liu X, van Grinsven B, Ameloot M, Fahlman M, Wagner P, Maes W, Haenen K. Boron-Doped Diamond Functionalization by an Electrografting/Alkyne-Azide Click Chemistry Sequence. ChemElectroChem 2014. [DOI: 10.1002/celc.201402068] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Kong S, Fontaine O, Roche J, Bouffier L, Kuhn A, Zigah D. Electropolymerization of polypyrrole by bipolar electrochemistry in an ionic liquid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2973-2976. [PMID: 24605863 DOI: 10.1021/la404916t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Bipolar electrochemistry has been recently explored for the modification of conducting micro- and nanoobjects with various surface layers. So far, it has been assumed that such processes should be carried out in low-conductivity electrolytes in order to be efficient. We report here the first bipolar electrochemistry experiment carried out in an ionic liquid, which by definition shows a relatively high conductivity. Pyrrole has been electropolymerized on a bipolar electrode, either in ionic liquid or in acetonitrile. The resulting polymer films were characterized by scanning electron microscopy and by contact profilometry. We demonstrate that the films obtained in an ionic liquid are thinner and smoother than the films synthesized in acetonitrile. Furthermore, a well-defined band of polypyrrole can be obtained in ionic liquid, in contrast to acetonitrile for which the polypyrrole film is present on the whole anodic part of the bipolar electrode.
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Affiliation(s)
- Shuwei Kong
- Université Bordeaux, ISM, UMR 5255 , F-33400 Talence, France
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18
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Yeap WS, Bevk D, Liu X, Krysova H, Pasquarelli A, Vanderzande D, Lutsen L, Kavan L, Fahlman M, Maes W, Haenen K. Diamond functionalization with light-harvesting molecular wires: improved surface coverage by optimized Suzuki cross-coupling conditions. RSC Adv 2014. [DOI: 10.1039/c4ra04740k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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19
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Pujari SP, Scheres L, van Lagen B, Zuilhof H. Organic monolayers from 1-alkynes covalently attached to chromium nitride: alkyl and fluoroalkyl termination. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10393-10404. [PMID: 23919532 DOI: 10.1021/la401978h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Strategies to modify chromium nitride (CrN) surfaces are important because of the increasing applications of these materials in various areas such as hybrid electronics, medical implants, diffusion barrier layers, corrosion inhibition, and wettability control. The present work presents the first surface immobilization of alkyl and perfluoro-alkyl (from C6 to C18) chains onto CrN substrates using appropriately functionalized 1-alkynes, yielding covalently bound, high-density organic monolayers with excellent hydrophobic properties and a high degree of short-range order. The obtained monolayers were characterized in detail by water contact angle, X-ray photoelectron spectroscopy (XPS), ellipsometry, and infrared reflection absorption spectroscopy (IRRAS).
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Affiliation(s)
- Sidharam P Pujari
- Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands
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20
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O’Leary LE, Rose MJ, Ding TX, Johansson E, Brunschwig BS, Lewis NS. Heck Coupling of Olefins to Mixed Methyl/Thienyl Monolayers on Si(111) Surfaces. J Am Chem Soc 2013; 135:10081-90. [DOI: 10.1021/ja402495e] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Leslie E. O’Leary
- Beckman Institute
and Kavli Nanosciences Institute, Division of Chemistry and Chemical Engineering, 210
Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, United States
| | - Michael J. Rose
- Beckman Institute
and Kavli Nanosciences Institute, Division of Chemistry and Chemical Engineering, 210
Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, United States
| | - Tina X. Ding
- Beckman Institute
and Kavli Nanosciences Institute, Division of Chemistry and Chemical Engineering, 210
Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, United States
| | - Erik Johansson
- Beckman Institute
and Kavli Nanosciences Institute, Division of Chemistry and Chemical Engineering, 210
Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, United States
| | - Bruce S. Brunschwig
- Beckman Institute
and Kavli Nanosciences Institute, Division of Chemistry and Chemical Engineering, 210
Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, United States
| | - Nathan S. Lewis
- Beckman Institute
and Kavli Nanosciences Institute, Division of Chemistry and Chemical Engineering, 210
Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, United States
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21
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Yang P, Yang W. Surface Chemoselective Phototransformation of C–H Bonds on Organic Polymeric Materials and Related High-Tech Applications. Chem Rev 2013; 113:5547-94. [PMID: 23614481 DOI: 10.1021/cr300246p] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Peng Yang
- Key Laboratory
of Applied Surface
and Colloid Chemistry, Ministry of Education, College of Chemistry
and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, China
| | - Wantai Yang
- The State Key Laboratory of
Chemical Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing
100029, China
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22
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Gerken JB, Rigsby ML, Ruther RE, Pérez-Rodríguez RJ, Guzei IA, Hamers RJ, Stahl SS. Modular Synthesis of Alkyne-Substituted Ruthenium Polypyridyl Complexes Suitable for “Click” Coupling. Inorg Chem 2013; 52:2796-8. [DOI: 10.1021/ic302827s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- James B. Gerken
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Matthew L. Rigsby
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Rose E. Ruther
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Riviam J. Pérez-Rodríguez
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Ilia A. Guzei
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Robert J. Hamers
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Shannon S. Stahl
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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23
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Franking R, Kim H, Chambers SA, Mangham AN, Hamers RJ. Photochemical grafting of organic alkenes to single-crystal TiO2 surfaces: a mechanistic study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:12085-12093. [PMID: 22746250 DOI: 10.1021/la302169k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The UV-induced photochemical grafting of terminal alkenes has emerged as a versatile way to form molecular layers on semiconductor surfaces. Recent studies have shown that grafting reactions can be initiated by photoelectron emission into the reactant liquid as well as by excitation across the semiconductor band gap, but the relative importance of these two processes is expected to depend on the nature of the semiconductors, the reactant alkene and the excitation wavelength. Here we report a study of the wavelength-dependent photochemical grafting of alkenes onto single-crystal TiO(2) samples. Trifluoroacetamide-protected 10-aminododec-1-ene (TFAAD), 10-N-BOC-aminodec-1-ene (t-BOC), and 1-dodecene were used as model alkenes. On rutile (110), photons with energy above the band gap but below the expected work function are not effective at inducing grafting, while photons with energy sufficient to induce electronic transitions from the TiO(2) Fermi level to electronic acceptor states of the reactant molecules induce grafting. A comparison of rutile (110), rutile (001), anatase (001), and anatase (101) samples shows slightly enhanced grafting for rutile but no difference between crystal faces for a given crystal phase. Hydroxylation of the surface increases the reaction rate by lowering the work function and thereby facilitating photoelectron ejection into the adjacent alkene. These results demonstrate that photoelectron emission is the dominant mechanism responsible for grafting when using short-wavelength (~254 nm) light and suggest that photoemission events beginning on mid-gap states may play a crucial role.
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Affiliation(s)
- Ryan Franking
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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24
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Li Y, Calder S, Yaffe O, Cahen D, Haick H, Kronik L, Zuilhof H. Hybrids of organic molecules and flat, oxide-free silicon: high-density monolayers, electronic properties, and functionalization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:9920-9929. [PMID: 22587009 DOI: 10.1021/la3010568] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Since the first report of Si-C bound organic monolayers on oxide-free Si almost two decades ago, a substantial amount of research has focused on studying the fundamental mechanical and electronic properties of these Si/molecule surfaces and interfaces. This feature article covers three closely related topics, including recent advances in achieving high-density organic monolayers (i.e., atomic coverage >55%) on oxide-free Si(111) substrates, an overview of progress in the fundamental understanding of the energetics and electronic properties of hybrid Si/molecule systems, and a brief summary of recent examples of subsequent functionalization on these high-density monolayers, which can significantly expand the range of applicability. Taken together, these topics provide an overview of the present status of this active area of research.
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Affiliation(s)
- Yan Li
- Laboratory of Organic Chemistry, Wageningen University, Wageningen, The Netherlands
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25
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Li Y, Zuilhof H. Photochemical grafting and patterning of organic monolayers on indium tin oxide substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:5350-5359. [PMID: 22324432 DOI: 10.1021/la204980f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Covalently attached organic layers on indium tin oxide (ITO) surfaces were prepared by the photochemical grafting with 1-alkenes. The surface modification was monitored with static water contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) measurements. Hydrophobic methyl-terminated ITO surfaces can be obtained via the grafting of tetradec-1-ene, whereas the attachment of ω-functionalized 1-alkenes leads to functionalized ITO surfaces. The use of a C≡C-Ge(CH(3))(3) terminus allows for facile tagging of the surface with an azido group via a one-pot deprotection/click reaction, resulting in bio/electronically active interfaces. The combination of nonaggressive chemicals (alkenes), mild reaction conditions (room temperature), and a light-induced grafting that facilitates the direct patterning of organic layers makes this simple approach highly promising for the development of ITO-based (bio)electronic devices.
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Affiliation(s)
- Yan Li
- Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands
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26
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Tudisco C, Betti P, Motta A, Pinalli R, Bombaci L, Dalcanale E, Condorelli GG. Cavitand-functionalized porous silicon as an active surface for organophosphorus vapor detection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:1782-1789. [PMID: 22185658 DOI: 10.1021/la203797b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper reports on the preparation of a porous silicon-based material covalently functionalized with cavitand receptors suited for the detection of organophosphorus vapors. Two different isomeric cavitands, both containing one acid group at the upper rim, specifically designed for covalent anchoring on silicon, were grafted on H-terminated porous silicon (PSi) by thermal hydrosilylation. The covalently functionalized surfaces and their complexation properties were characterized by combining different analytical techniques, namely X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and mass spectroscopy analysis coupled with thermal desorption experiments. Complexation experiments were performed by exposing both active surfaces and a control surface consisting of PSi functionalized with a structurally similar but inactive methylene-bridged cavitand (MeCav) to dimethyl methylphosphonate (DMMP) vapors. Comparison between active and inactive surfaces demonstrated the recognition properties of the new surfaces. Finally, the nature of the involved interactions, the energetic differences between active and inactive surfaces toward DMMP complexation, and the comparison with a true nerve gas agent (sarin) were studied by DFT modeling. The results revealed the successful grafting reaction, the specific host-guest interactions of the PSi-bonded receptors, and the reversibility of the guest complexation.
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Affiliation(s)
- Cristina Tudisco
- Dipartimento di Scienze Chimiche, Università di Catania and INSTM UdR di Catania, v.le A. Doria 6, 95125 Catania, Italy
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27
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Shah S, Benson MC, Bishop LM, Huhn AM, Ruther RE, Yeager JC, Tan Y, Louis KM, Hamers RJ. Chemically assembled heterojunctions of SnO2 nanorods with TiO2 nanoparticles via “click” chemistry. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm31227a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Ruther RE, Franking R, Huhn AM, Gomez-Zayas J, Hamers RJ. Formation of smooth, conformal molecular layers on ZnO surfaces via photochemical grafting. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10604-10614. [PMID: 21777005 DOI: 10.1021/la2011265] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have investigated the photochemical grafting of organic alkenes to atomically flat ZnO(10 ̅10) single crystals and ZnO nanorods as a way to produce functional molecule-semiconductor interfaces. Atomic force microscopy shows that photochemical grafting produces highly conformal, smooth molecular layers with no detectable changes in the underlying structure of the ZnO terraces or steps. X-ray photoelectron spectroscopy measurements show that grafting of a methyl ester-terminated alkene terminates near one monolayer, while alkenes bearing a trifluoroacetamide-protected amine form very smooth multilayers. Even with multilayers, it is possible to deprotect the amines and to link a second molecule to the surface with excellent efficiency and without significant loss of molecules from the surface. This demonstrates that the use of photochemical grafting, even in the case of multilayer formation, enables multistep chemical processes to be conducted on the ZnO surface. Photoresponse measurements demonstrate that functionalization of the surface does not affect the ability to induce field effects in the underlying ZnO, thereby suggesting that this approach to functionalization may be useful for applications in sensing and in hybrid organic-inorganic transistors and related devices.
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Affiliation(s)
- Rose E Ruther
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, Wisconsin 53706, USA
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29
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Chen J, Franking R, Ruther RE, Tan Y, He X, Hogendoorn SR, Hamers RJ. Formation of molecular monolayers on TiO2 surfaces: a surface analogue of the Williamson ether synthesis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:6879-6889. [PMID: 21528935 DOI: 10.1021/la2008528] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Strategies to modify metal oxide surfaces are important because of the increasing applications of metal oxides in catalysis, sensing, electronics, and renewable energy. Here, we report the formation of molecular monolayers on anatase nanocrystalline TiO(2) surfaces at near-ambient temperatures by a simple one-step immersion. This is achieved by an analogue of the Williamson ether synthesis, in which the hydroxyl groups of the TiO(2) surface react with iodo-alkane molecules to release HI and form a Ti-O-C surface linkage. The grafted molecules were characterized by Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the formation of covalently bonded monolayers. Kinetic studies yielded an activation barrier of ∼59 kJ/mol for the grafting reaction. Measurements of hydrolytic stability of the grafted molecules in water show that approximately half the molecules are removed within minutes to hours at temperatures of 25-100 °C with an activation energy of ∼82 kJ/mol, while the remaining molecules are stable for much longer periods of time. These different stabilities are discussed in terms of the different types of Ti-O-C bonds that can form on TiO(2) surfaces.
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Affiliation(s)
- Jixin Chen
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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30
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Ruther RE, Rigsby ML, Gerken JB, Hogendoorn SR, Landis EC, Stahl SS, Hamers RJ. Highly Stable Redox-Active Molecular Layers by Covalent Grafting to Conductive Diamond. J Am Chem Soc 2011; 133:5692-4. [DOI: 10.1021/ja200210t] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Amiaud L, Martin I, Milosavljević AR, Michaelson S, Hoffman A, Azria R, Lafosse A. Low-energy electron scattering on deuterated nanocrystalline diamond films—a model system for understanding the interplay between density-of-states, excitation mechanisms and surface versus lattice contributions. Phys Chem Chem Phys 2011; 13:11495-502. [DOI: 10.1039/c1cp20219g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Qin G, Santos C, Zhang W, Li Y, Kumar A, Erasquin UJ, Liu K, Muradov P, Trautner BW, Cai C. Biofunctionalization on alkylated silicon substrate surfaces via "click" chemistry. J Am Chem Soc 2010; 132:16432-41. [PMID: 21033708 PMCID: PMC3059218 DOI: 10.1021/ja1025497] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Biofunctionalization of silicon substrates is important to the development of silicon-based biosensors and devices. Compared to conventional organosiloxane films on silicon oxide intermediate layers, organic monolayers directly bound to the nonoxidized silicon substrates via Si-C bonds enhance the sensitivity of detection and the stability against hydrolytic cleavage. Such monolayers presenting a high density of terminal alkynyl groups for bioconjugation via copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC, a "click" reaction) were reported. However, yields of the CuAAC reactions on these monolayer platforms were low. Also, the nonspecific adsorption of proteins on the resultant surfaces remained a major obstacle for many potential biological applications. Herein, we report a new type of "clickable" monolayers grown by selective, photoactivated surface hydrosilylation of α,ω-alkenynes, where the alkynyl terminal is protected with a trimethylgermanyl (TMG) group, on hydrogen-terminated silicon substrates. The TMG groups on the film are readily removed in aqueous solutions in the presence of Cu(I). Significantly, the degermanylation and the subsequent CuAAC reaction with various azides could be combined into a single step in good yields. Thus, oligo(ethylene glycol) (OEG) with an azido tag was attached to the TMG-alkyne surfaces, leading to OEG-terminated surfaces that reduced the nonspecific adsorption of protein (fibrinogen) by >98%. The CuAAC reaction could be performed in microarray format to generate arrays of mannose and biotin with varied densities on the protein-resistant OEG background. We also demonstrated that the monolayer platform could be functionalized with mannose for highly specific capturing of living targets (Escherichia coli expressing fimbriae) onto the silicon substrates.
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