1
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Dong A, Sohn L, Lustig M. Metal-pad-enhanced resistive pulse sensor reveals complex-valued Braess paradox. Phys Rev E 2023; 108:014408. [PMID: 37583237 PMCID: PMC10829567 DOI: 10.1103/physreve.108.014408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/26/2023] [Indexed: 08/17/2023]
Abstract
A resistive pulse sensor measures the electrical impedance of an electrolyte-filled channel as particles flow through it. Ordinarily, the presence of a nonconductive particle increases the impedance of the channel. Here we report a surprising experimental result in which a microfluidic resistive pulse sensor experiences the opposite effect: The presence of a nonconductive particle decreases the channel impedance. We explain the counterintuitive phenomenon by relating to the Braess paradox from traffic network theory, and we call it the complex-valued Braess paradox (CVBP). We develop theoretical models to study the CVBP and corroborate the experimental data using finite element simulations and lumped-element circuit modeling. We then discuss implications and potential applications of the CVBP in resistive pulse sensing and beyond.
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Affiliation(s)
- Alan Dong
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, California 94720, USA
| | - Lydia Sohn
- Department of Mechanical Engineering, University of California, Berkeley, Berkeley, California 94720, USA
| | - Michael Lustig
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, California 94720, USA
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2
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Emmerich MEP, Sinnigen AS, Neubauer P, Birkholz M. Dielectrophoretic separation of blood cells. Biomed Microdevices 2022; 24:30. [PMID: 36006519 PMCID: PMC9411249 DOI: 10.1007/s10544-022-00623-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2022] [Indexed: 11/02/2022]
Abstract
Microfluidic dielectrophoretic (DEP) devices enable the label-free separation and isolation of cells based on differences in their electrophysiological properties. The technique can serve as a tool in clinical diagnostics and medical research as it facilitates the analysis of patient-specific blood composition and the detection and isolation of pathogenic cells like circulating tumor cells or malaria-infected erythrocytes. This review compares different microfluidic DEP devices to separate platelets, erythrocytes and leukocytes including their cellular subclasses. An overview and experimental setups of different microfluidic DEP devices for the separation, trapping and isolation or purification of blood cells are detailed with respect to their technical design, electrode configuration, sample preparation, applied voltage and frequency and created DEP field based and related to the separation efficiency. The technique holds the promise that results can quickly be attained in clinical and ambulant settings. In particular, point-of-care-testing scenarios are favored by the extensive miniaturization, which would be enabled by microelectronical integration of DEP devices.
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Affiliation(s)
- Maria E. P. Emmerich
- Chair of Bioprocess Engineering, Institute of Biotechnology, TU Berlin, Ackerstrasse 76, ACK24, D-13355 Berlin, Germany
- IHP – Leibniz-Institut für innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
| | - Anne-Sophie Sinnigen
- Chair of Bioprocess Engineering, Institute of Biotechnology, TU Berlin, Ackerstrasse 76, ACK24, D-13355 Berlin, Germany
| | - Peter Neubauer
- Chair of Bioprocess Engineering, Institute of Biotechnology, TU Berlin, Ackerstrasse 76, ACK24, D-13355 Berlin, Germany
| | - Mario Birkholz
- IHP – Leibniz-Institut für innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
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3
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Mariano A, Lubrano C, Bruno U, Ausilio C, Dinger NB, Santoro F. Advances in Cell-Conductive Polymer Biointerfaces and Role of the Plasma Membrane. Chem Rev 2022; 122:4552-4580. [PMID: 34582168 PMCID: PMC8874911 DOI: 10.1021/acs.chemrev.1c00363] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Indexed: 02/07/2023]
Abstract
The plasma membrane (PM) is often described as a wall, a physical barrier separating the cell cytoplasm from the extracellular matrix (ECM). Yet, this wall is a highly dynamic structure that can stretch, bend, and bud, allowing cells to respond and adapt to their surrounding environment. Inspired by shapes and geometries found in the biological world and exploiting the intrinsic properties of conductive polymers (CPs), several biomimetic strategies based on substrate dimensionality have been tailored in order to optimize the cell-chip coupling. Furthermore, device biofunctionalization through the use of ECM proteins or lipid bilayers have proven successful approaches to further maximize interfacial interactions. As the bio-electronic field aims at narrowing the gap between the electronic and the biological world, the possibility of effectively disguising conductive materials to "trick" cells to recognize artificial devices as part of their biological environment is a promising approach on the road to the seamless platform integration with cells.
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Affiliation(s)
- Anna Mariano
- Tissue
Electronics, Istituto Italiano di Tecnologia, 80125 Naples, Italy
| | - Claudia Lubrano
- Tissue
Electronics, Istituto Italiano di Tecnologia, 80125 Naples, Italy
- Dipartimento
di Chimica, Materiali e Produzione Industriale, Università di Napoli Federico II, 80125 Naples, Italy
| | - Ugo Bruno
- Tissue
Electronics, Istituto Italiano di Tecnologia, 80125 Naples, Italy
- Dipartimento
di Chimica, Materiali e Produzione Industriale, Università di Napoli Federico II, 80125 Naples, Italy
| | - Chiara Ausilio
- Tissue
Electronics, Istituto Italiano di Tecnologia, 80125 Naples, Italy
| | - Nikita Bhupesh Dinger
- Tissue
Electronics, Istituto Italiano di Tecnologia, 80125 Naples, Italy
- Dipartimento
di Chimica, Materiali e Produzione Industriale, Università di Napoli Federico II, 80125 Naples, Italy
| | - Francesca Santoro
- Tissue
Electronics, Istituto Italiano di Tecnologia, 80125 Naples, Italy
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4
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Bakhtiari S, Manshadi MKD, Mansoorifar A, Beskok A. A Microfluidic Dielectric Spectroscopy System for Characterization of Biological Cells in Physiological Media. SENSORS (BASEL, SWITZERLAND) 2022; 22:463. [PMID: 35062423 PMCID: PMC8779508 DOI: 10.3390/s22020463] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/31/2021] [Accepted: 01/05/2022] [Indexed: 02/04/2023]
Abstract
Dielectric spectroscopy (DS) is a promising cell screening method that can be used for diagnostic and drug discovery purposes. The primary challenge of using DS in physiological buffers is the electrode polarization (EP) that overwhelms the impedance signal within a large frequency range. These effects further amplify with the miniaturization of the measurement electrodes. In this study, we present a microfluidic system and the associated equivalent circuit models for real-time measurements of cell membrane capacitance and cytoplasm resistance in physiological buffers with 10 s increments. The current device captures several hundreds of biological cells in individual microwells through gravitational settling and measures the system's impedance using microelectrodes covered with dendritic gold nanostructures. Using PC-3 cells (a highly metastatic prostate cancer cell line) suspended in cell growth media (CGM), we demonstrate stable measurements of cell membrane capacitance and cytoplasm resistance in the device for over 15 min. We also describe a consistent application of the equivalent circuit model, starting from the reference measurements used to determine the system parameters. The circuit model is tested using devices with varying dimensions, and the obtained cell parameters between different devices are nearly identical. Further analyses of the impedance data have shown that accurate cell membrane capacitance and cytoplasm resistance can be extracted using a limited number of measurements in the 5 MHz to 10 MHz range. This will potentially reduce the timescale required for real-time DS measurements below 1 s. Overall, the new microfluidic device can be used for the dielectric characterization of biological cells in physiological buffers for various cell screening applications.
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Affiliation(s)
| | | | | | - Ali Beskok
- Mechanical Engineering Department, Southern Methodist University, Dallas, TX 75275, USA; (S.B.); (M.K.D.M.); (A.M.)
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5
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Woo H, Kim S, Nam H, Choi W, Shin K, Kim K, Yoon S, Kim GH, Kim J, Lim G. Au Hierarchical Nanostructure-Based Surface Modification of Microelectrodes for Improved Neural Signal Recording. Anal Chem 2021; 93:11765-11774. [PMID: 34387479 DOI: 10.1021/acs.analchem.1c02168] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Microelectrodes are widely used for neural signal analysis because they can record high-resolution signals. In general, the smaller the size of the microelectrode for obtaining a high-resolution signal, the higher the impedance and noise value of the electrodes. Therefore, to improve the signal-to-noise ratio (SNR) of neural signals, it is important to develop microelectrodes with low impedance and noise. In this research, an Au hierarchical nanostructure (AHN) was deposited to improve the electrochemical surface area (ECSA) of a microelectrode. Au nanostructures on different scales were deposited on the electrode surface in a hierarchical structure using an electrochemical deposition method. The AHN-modified microelectrode exhibited an average of 80% improvement in impedance compared to a bare microelectrode. Through electrochemical impedance spectroscopy analysis and impedance equivalent circuit modeling, the increase in the ECSA due to the AHN was confirmed. After evaluating the cell cytotoxicity of the AHN-modified microelectrode through an in vitro test, neural signals from rats were obtained in in vivo experiments. The AHN-modified microelectrode exhibited an approximate 9.79 dB improvement in SNR compared to the bare microelectrode. This surface modification technology is a post-treatment strategy used for existing fabricated electrodes, so it can be applied to microelectrode arrays and nerve electrodes made from various structures and materials.
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Affiliation(s)
| | | | | | - Wonsuk Choi
- Center for Bionics, Korea Institute of Science and Technology (KIST), 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Kumjae Shin
- Construction Equipment Technology Center, Korea Institute of Industrial Technology (KITECH), 288-1, Daehak-ri, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 38408, Republic of Korea
| | | | | | - Geon Hwee Kim
- School of Mechanical Engineering, Chungbuk National University (CBNU), 1, Chungdae-ro, Seowon-gu, Cheongju-si, Chungcheongbuk-do 28644, Republic of Korea
| | - Jinseok Kim
- Center for Bionics, Korea Institute of Science and Technology (KIST), 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
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6
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Sarno B, Heineck D, Heller MJ, Ibsen SD. Dielectrophoresis: Developments and applications from 2010 to 2020. Electrophoresis 2021; 42:539-564. [PMID: 33191521 PMCID: PMC7986072 DOI: 10.1002/elps.202000156] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/22/2020] [Accepted: 10/21/2020] [Indexed: 12/19/2022]
Abstract
The 20th century has seen tremendous innovation of dielectrophoresis (DEP) technologies, with applications being developed in areas ranging from industrial processing to micro- and nanoscale biotechnology. From 2010 to present day, there have been 981 publications about DEP. Of over 2600 DEP patents held by the United States Patent and Trademark Office, 106 were filed in 2019 alone. This review focuses on DEP-based technologies and application developments between 2010 and 2020, with an aim to highlight the progress and to identify potential areas for future research. A major trend over the last 10 years has been the use of DEP techniques for biological and clinical applications. It has been used in various forms on a diverse array of biologically derived molecules and particles to manipulate and study them including proteins, exosomes, bacteria, yeast, stem cells, cancer cells, and blood cells. DEP has also been used to manipulate nano- and micron-sized particles in order to fabricate different structures. The next 10 years are likely to see the increase in DEP-related patent applications begin to result in a greater level of technology commercialization. Also during this time, innovations in DEP technology will likely be leveraged to continue the existing trend to further biological and medical-focused applications as well as applications in microfabrication. As a tool leveraged by engineering and imaginative scientific design, DEP offers unique capabilities to manipulate small particles in precise ways that can help solve problems and enable scientific inquiry that cannot be addressed using conventional methods.
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Affiliation(s)
- Benjamin Sarno
- Oregon Health and Science University–The Knight Cancer Institute's Cancer Early Detection Advanced Research CenterPortlandORUSA
- University of California San Diego–NanoengineeringLa JollaCAUSA
| | - Daniel Heineck
- Oregon Health and Science University–The Knight Cancer Institute's Cancer Early Detection Advanced Research CenterPortlandORUSA
| | - Michael J. Heller
- Oregon Health and Science University–The Knight Cancer Institute's Cancer Early Detection Advanced Research CenterPortlandORUSA
- University of California San Diego–NanoengineeringLa JollaCAUSA
| | - Stuart D. Ibsen
- Oregon Health and Science University–The Knight Cancer Institute's Cancer Early Detection Advanced Research CenterPortlandORUSA
- Oregon Health and Science University–Biomedical EngineeringPortlandORUSA
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7
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Sabuncu AC, Muldur S, Cetin B, Usta OB, Aubry N. β-Dispersion of blood during sedimentation. Sci Rep 2021; 11:2642. [PMID: 33514847 PMCID: PMC7846779 DOI: 10.1038/s41598-021-82171-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 01/08/2021] [Indexed: 01/30/2023] Open
Abstract
Aggregation of human red blood cells (RBC) is central to various pathological conditions from bacterial infections to cancer. When left at low shear conditions or at hemostasis, RBCs form aggregates, which resemble stacks of coins, known as 'rouleaux'. We experimentally examined the interfacial dielectric dispersion of aggregating RBCs. Hetastarch, an RBC aggregation agent, is used to mimic conditions leading to aggregation. Hetastrach concentration is incrementally increased in blood from healthy donors to measure the sensitivity of the technique. Time lapse electrical impedance measurements were conducted as red blood cells form rouleaux and sediment in a PDMS chamber. Theoretical modeling was used for obtaining complex permittivity of an effective single red blood cell aggregate at various concentrations of hetastarch. Time response of red blood cells' impedance was also studied to parametrize the time evolution of impedance data. Single aggregate permittivity at the onset of aggregation, evolution of interfacial dispersion parameters, and sedimentation kinetics allowed us to distinguish differential aggregation in blood.
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Affiliation(s)
- Ahmet C Sabuncu
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, 01609, USA.
| | - Sinan Muldur
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School and Shriners Hospitals for Children, Boston, MA, 02114, USA
| | - Barbaros Cetin
- Microfluidics & Lab-On-a-Chip Research Group, Department of Mechanical Engineering, I.D. Bilkent University, Ankara, Turkey
| | - O Berk Usta
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School and Shriners Hospitals for Children, Boston, MA, 02114, USA
| | - Nadine Aubry
- School of Engineering, Tufts University, Medford, MA, 02155, USA
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8
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Koklu A, Giuliani J, Monton C, Beskok A. Rapid and Sensitive Detection of Nanomolecules by an AC Electrothermal Flow Facilitated Impedance Immunosensor. Anal Chem 2020; 92:7762-7769. [DOI: 10.1021/acs.analchem.0c00890] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Anil Koklu
- Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jason Giuliani
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Carlos Monton
- General Atomics, P.O. Box 85608, San Diego, California 92186 United States
| | - Ali Beskok
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
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9
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Koklu A, El Helou A, Raad PE, Beskok A. Characterization of Temperature Rise in Alternating Current Electrothermal Flow Using Thermoreflectance Method. Anal Chem 2019; 91:12492-12500. [DOI: 10.1021/acs.analchem.9b03238] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Anil Koklu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Assaad El Helou
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Peter E. Raad
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Ali Beskok
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
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10
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Xiao G, Song Y, Zhang Y, Xu S, Xing Y, Wang M, Cai X. Platinum/Graphene Oxide Coated Microfabricated Arrays for Multinucleus Neural Activities Detection in the Rat Models of Parkinson’s Disease Treated by Apomorphine. ACS APPLIED BIO MATERIALS 2019; 2:4010-4019. [DOI: 10.1021/acsabm.9b00541] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Guihua Xiao
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yilin Song
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Zhang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shengwei Xu
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Xing
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Mixia Wang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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11
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Koklu A, Ajaev V, Beskok A. Self-Similar Response of Electrode Polarization for Binary Electrolytes in Parallel Plate Capacitor Systems. Anal Chem 2019; 91:11231-11239. [DOI: 10.1021/acs.analchem.9b02162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Anil Koklu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Vladimir Ajaev
- Department of Mathematics, Southern Methodist University, Dallas, Texas 75275, United States
| | - Ali Beskok
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
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12
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Koklu A, Atmaramani R, Hammack A, Beskok A, Pancrazio JJ, Gnade BE, Black BJ. Gold nanostructure microelectrode arrays for in vitro recording and stimulation from neuronal networks. NANOTECHNOLOGY 2019; 30:235501. [PMID: 30776783 DOI: 10.1088/1361-6528/ab07cd] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
An ideal microelectrode array (MEA) design should include materials and structures which exhibit biocompatibility, low electrode polarization, low impedance/noise, and structural durability. Here, the fabrication of MEAs with indium tin oxide (ITO) electrodes deposited with self-similar gold nanostructures (GNS) is described. We show that fern leaf fractal-like GNS deposited on ITO electrodes are conducive for neural cell attachment and viability while reducing the interfacial impedance more than two orders of magnitude at low frequencies (100-1000 Hz) versus bare ITO. GNS MEAs, with low interfacial impedance, allowed the detection of extracellular action potentials with excellent signal-to-noise ratios (SNR, 20.26 ± 2.14). Additionally, the modified electrodes demonstrated electrochemical and mechanical stability over 29 d in vitro.
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Affiliation(s)
- Anil Koklu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, 75205, United States of America
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13
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Martins M, Gomes P, Oliveira C, Coimbra M, da Silva HP. Design and Evaluation of a Diaphragm for Electrocardiography in Electronic Stethoscopes. IEEE Trans Biomed Eng 2019; 67:391-398. [PMID: 31034406 DOI: 10.1109/tbme.2019.2913913] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Combining Phonocardiography (PCG) and Electrocardiography (ECG) data has been recognized within the state-of-the-art as of added value for enhanced cardiovascular assessment. However, multiple aspects of ECG data acquisition in a stethoscope form factor remain unstudied, and existing devices typically enforce a substantial change into routine clinical auscultation procedures, with predictably low technology acceptance. As such, in this paper, we present a novel approach to ECG data acquisition throughout the five main cardiac auscultation points, and that intends to be incorporated in a commonly used electronic stethoscope. Therefore, it enables analysis and acquisition of both PCG and ECG signals in a single pass. We describe the development, experimental evaluation, and comparison of the ECG signals obtained using our proposed approach and a gold standard medical device, through metrics that allow the evaluation of morphological similarities. Results point to a high correlation between the two evaluated setups, thus supporting the idea of meaningfully collecting ECG data along medical auscultation points with the proposed form factor. Moreover, this work has led us to conclude that for the studied population, signals acquired on focuses F1, F2, and F3 are usually highly correlated with leads V1 and V2 of the standard ECG medical recording procedure.
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14
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Mansoorifar A, Koklu A, Beskok A. Quantification of Cell Death Using an Impedance-Based Microfluidic Device. Anal Chem 2019; 91:4140-4148. [PMID: 30793881 DOI: 10.1021/acs.analchem.8b05890] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Dielectric spectroscopy is a nondestructive method to characterize dielectric properties by measuring impedance data over a frequency spectrum. This method has been widely used for various applications such as counting, sizing, and monitoring biological cells and particles. Recently, utilization of this method has been suggested in various stages of the drug discovery process due to low sample consumption and fast analysis time. In this study, we used a previously developed microfluidic system to confine single PC-3 cells in microwells using dielectrophoretic forces and perform the impedance measurements. PC-3 cells are treated with 100 μM Enzalutamide drug, and their impedance response is recorded until the cells are totally dead as predicted with viability tests. Four different approaches are used to analyze the impedance spectrum. Equivalent circuit modeling is used to extract the cell electrical properties as a function of time. Principal component analysis (PCA) is used to quantify cellular response to drug as a function of time. Single frequency measurements are conducted to observe how the cells respond over time. Finally, opacity ratio is defined as an additional quantification method. This device is capable of quantitatively measuring drug effects on biological cells and detecting cell death. The results show that the proposed microfluidic system has the potential to be used in early stages of the drug discovery process.
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Affiliation(s)
- Amin Mansoorifar
- Department of Mechanical Engineering , Southern Methodist University , Dallas , Texas 75205 , United States
| | - Anil Koklu
- Department of Mechanical Engineering , Southern Methodist University , Dallas , Texas 75205 , United States
| | - Ali Beskok
- Department of Mechanical Engineering , Southern Methodist University , Dallas , Texas 75205 , United States
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15
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Koklu A, Mansoorifar A, Giuliani J, Monton C, Beskok A. Self-Similar Interfacial Impedance of Electrodes in High Conductivity Media: II. Disk Electrodes. Anal Chem 2018; 91:2455-2463. [DOI: 10.1021/acs.analchem.8b05275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Anil Koklu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Amin Mansoorifar
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Jason Giuliani
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Carlos Monton
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Ali Beskok
- Department of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
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16
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Koklu A, Mansoorifar A, Beskok A. Effects of electrode size and surface morphology on electrode polarization in physiological buffers. Electrophoresis 2018. [DOI: 10.1002/elps.201800303] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Anil Koklu
- Department of Mechanical Engineering; Southern Methodist University; Dallas TX USA
| | - Amin Mansoorifar
- Department of Mechanical Engineering; Southern Methodist University; Dallas TX USA
| | - Ali Beskok
- Department of Mechanical Engineering; Southern Methodist University; Dallas TX USA
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17
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Sabuncu AC, Shen J, Zaki MH, Beskok A. Changes in the dielectric spectra of murine colon during neoplastic progression. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aaad81] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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18
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Mansoorifar A, Koklu A, Ma S, Raj GV, Beskok A. Electrical Impedance Measurements of Biological Cells in Response to External Stimuli. Anal Chem 2018; 90:4320-4327. [PMID: 29402081 DOI: 10.1021/acs.analchem.7b05392] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Dielectric spectroscopy (DS) is a noninvasive technique for real-time measurements of the impedance spectra of biological cells. DS enables characterization of cellular dielectric properties such as membrane capacitance and cytoplasmic conductivity. We have developed a lab-on-a-chip device that uses an electro-activated microwells array for capturing, DS measurements, and unloading of biological cells. Impedance measurements were conducted at 0.2 V in the 10 kHz to 40 MHz range with 6 s time resolution. An equivalent circuit model was developed to extract the cell membrane capacitance and cell cytoplasmic conductivity from the impedance spectra. A human prostate cancer cell line, PC-3, was used to evaluate the device performance. Suspension of PC-3 cells in low conductivity buffers (LCB) enhanced their dielectrophoretic trapping and impedance response. We report the time course of the variations in dielectric properties of PC-3 cells suspended in LCB and their response to sudden pH change from a pH of 7.3 to a pH of 5.8. Importantly, we demonstrated that our device enabled real-time measurements of dielectric properties of live cancer cells and allowed the assessment of the cellular response to variations in buffer conductivity and pH. These data support further development of this device toward single cell measurements.
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Affiliation(s)
- Amin Mansoorifar
- Department of Mechanical Engineering , Southern Methodist University , Dallas , Texas 75205 , United States
| | - Anil Koklu
- Department of Mechanical Engineering , Southern Methodist University , Dallas , Texas 75205 , United States
| | - Shihong Ma
- Departments of Urology and Pharmacology , University of Texas Southwestern Medical Center , Dallas , Texas 75390 , United States
| | - Ganesh V Raj
- Departments of Urology and Pharmacology , University of Texas Southwestern Medical Center , Dallas , Texas 75390 , United States
| | - Ali Beskok
- Department of Mechanical Engineering , Southern Methodist University , Dallas , Texas 75205 , United States
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Koklu A, Mansoorifar A, Beskok A. Self-Similar Interfacial Impedance of Electrodes in High Conductivity Media. Anal Chem 2017; 89:12533-12540. [DOI: 10.1021/acs.analchem.7b03753] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Anil Koklu
- Department
of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Amin Mansoorifar
- Department
of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
| | - Ali Beskok
- Department
of Mechanical Engineering, Southern Methodist University, Dallas, Texas 75205, United States
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20
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Dielectric properties of isolated adrenal chromaffin cells determined by microfluidic impedance spectroscopy. Bioelectrochemistry 2017; 119:84-91. [PMID: 28918192 DOI: 10.1016/j.bioelechem.2017.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 01/07/2023]
Abstract
Knowledge of the dielectric properties of biological cells plays an important role in numerical models aimed at understanding how high intensity ultrashort nanosecond electric pulses affect the plasma membrane and the membranes of intracellular organelles. To this end, using electrical impedance spectroscopy, the dielectric properties of isolated, neuroendocrine adrenal chromaffin cells were obtained. Measured impedance data of the cell suspension, acquired between 1kHz and 20MHz, were fit into a combination of constant phase element and Cole-Cole models from which the effect of electrode polarization was extracted. The dielectric spectrum of each cell suspension was fit into a Maxwell-Wagner mixture model and the Clausius-Mossotti factor was obtained. Lastly, to extract the cellular dielectric parameters, the cell dielectric data were fit into a granular cell model representative of a chromaffin cell, which was based on the inclusion of secretory granules in the cytoplasm. Chromaffin cell parameters determined from this study were the cell and secretory granule membrane specific capacitance (1.22 and 7.10μF/cm2, respectively), the cytoplasmic conductivity, which excludes and includes the effect of intracellular membranous structures (1.14 and 0.49S/m, respectively), and the secretory granule milieu conductivity (0.35S/m). These measurements will be crucial for incorporating into numerical models aimed at understanding the differential poration effect of nanosecond electric pulses on chromaffin cell membranes.
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Mansoorifar A, Ghosh A, Sabuncu AC, Beskok A. Accuracy of the Maxwell–Wagner and the Bruggeman–Hanai mixture models for single cell dielectric spectroscopy. IET Nanobiotechnol 2017. [DOI: 10.1049/iet-nbt.2017.0064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Amin Mansoorifar
- Mechanical Engineering DepartmentSouthern Methodist UniversityDallasTX 75205USA
| | - Arindam Ghosh
- Mechanical Engineering DepartmentVirginia Tech UniversityBlacksburgVA 24061USA
| | - Ahmet C. Sabuncu
- Mechanical Engineering DepartmentSouthern Methodist UniversityDallasTX 75205USA
| | - Ali Beskok
- Mechanical Engineering DepartmentSouthern Methodist UniversityDallasTX 75205USA
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Mansoorifar A, Koklu A, Sabuncu AC, Beskok A. Dielectrophoresis assisted loading and unloading of microwells for impedance spectroscopy. Electrophoresis 2017; 38:1466-1474. [PMID: 28256738 PMCID: PMC5547746 DOI: 10.1002/elps.201700020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/19/2022]
Abstract
Dielectric spectroscopy (DS) is a noninvasive, label-free, fast, and promising technique for measuring dielectric properties of biological cells in real time. We demonstrate a microchip that consists of electro-activated microwell arrays for positive dielectrophoresis assisted cell capture, DS measurements, and negative dielectrophoresis driven cell unloading; thus, providing a high-throughput cell analysis platform. To the best of our knowledge, this is the first microfluidic chip that combines electro-activated microwells and DS to analyze biological cells. Device performance is tested using Saccharomyces cerevisiae (yeast) cells. DEP response of yeast cells is determined by measuring their Clausius-Mossotti factor using biophysical models in parallel plate microelectrode geometry. This information is used to determine the excitation frequency to load and unload wells. Effect of yeast cells on the measured impedance spectrum was examined both experimentally and numerically. Good match between the numerical and experimental results establishes the potential use of the microchip device for extracting subcellular properties of biological cells in a rapid and nonexpensive manner.
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Affiliation(s)
- Amin Mansoorifar
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX 75205, USA
| | - Anil Koklu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX 75205, USA
| | - Ahmet Can Sabuncu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX 75205, USA
| | - Ali Beskok
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX 75205, USA
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Koklu A, Sabuncu AC, Beskok A. Enhancement of dielectrophoresis using fractal gold nanostructured electrodes. Electrophoresis 2017; 38:1458-1465. [PMID: 28130914 DOI: 10.1002/elps.201600456] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/30/2016] [Accepted: 01/22/2017] [Indexed: 11/07/2022]
Abstract
Dielectrophoretic motions of Saccharomyces cerevisiae (yeast) cells and colloidal gold are investigated using electrochemically modified electrodes exhibiting fractal topology. Electrodeposition of gold on electrodes generated repeated patterns with a fern-leaf type self-similarity. A particle tracking algorithm is used to extract dielectrophoretic particle velocities using fractal and planar electrodes in two different medium conductivities. The results show increased dielectrophoretic force when using fractal electrodes. Strong negative dielectrophoresis of yeast cells in high-conductivity media (1.5 S/m) is observed using fractal electrodes, while no significant motion is present using planar electrodes. Electrical impedance at the electrode/electrolyte interface is measured using impedance spectroscopy technique. Stronger electrode polarization (EP) effects are reported for planar electrodes. Decreased EP in fractal electrodes is considered as a reason for enhanced dielectrophoretic response.
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Affiliation(s)
- Anil Koklu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, USA
| | - Ahmet C Sabuncu
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, USA
| | - Ali Beskok
- Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, USA
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