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Shoute LCT, Charlton CL, Kanji JN, Babiuk S, Babiuk L, Chen J. Faradaic Impedimetric Immunosensor for Label-Free Point-of-Care Detection of COVID-19 Antibodies Using Gold-Interdigitated Electrode Array. BIOSENSORS 2023; 14:6. [PMID: 38248383 PMCID: PMC10812953 DOI: 10.3390/bios14010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 01/23/2024]
Abstract
Label-free electrochemical biosensors have many desirable characteristics in terms of miniaturization, scalability, digitization, and other attributes associated with point-of-care (POC) applications. In the era of COVID-19 and pandemic preparedness, further development of such biosensors will be immensely beneficial for rapid testing and disease management. Label-free electrochemical biosensors often employ [Fe(CN)6]-3/4 redox probes to detect low-concentration target analytes as they dramatically enhance sensitivity. However, such Faradaic-based sensors are reported to experience baseline signal drift, which compromises the performance of these devices. Here, we describe the use of a mecaptohexanoic (MHA) self-assembled monolayer (SAM) modified Au-interdigitated electrode arrays (IDA) to investigate the origin of the baseline signal drift, developed a protocol to resolve the issue, and presented insights into the underlying mechanism on the working of label-free electrochemical biosensors. Using this protocol, we demonstrate the application of MHA SAM-modified Au-IDA for POC analysis of human serum samples. We describe the use of a label-free electrochemical biosensor based on covalently conjugated SARS-CoV-2 spike protein for POC detection of COVID-19 antibodies. The test requires a short incubation time (10 min), and has a sensitivity of 35.4/decade (35.4%/10 ng mL-1) and LOD of 21 ng/mL. Negligible cross reactivity to seasonal human coronavirus or other endogenous antibodies was observed. Our studies also show that Faradaic biosensors are ~17 times more sensitive than non-Faradaic biosensors. We believe the work presented here contributes to the fundamental understanding of the underlying mechanisms of baseline signal drift and will be applicable to future development of electrochemical biosensors for POC applications.
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Affiliation(s)
- Lian C. T. Shoute
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada;
| | - Carmen L. Charlton
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB T6G 1C9, Canada; (C.L.C.); (J.N.K.)
- Public Health Laboratory, Alberta Precision Laboratories, Calgary, AB T2N 1M7, Canada
- Li Ka Shing Institute for Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Jamil N. Kanji
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB T6G 1C9, Canada; (C.L.C.); (J.N.K.)
- Public Health Laboratory, Alberta Precision Laboratories, Calgary, AB T2N 1M7, Canada
- Division of Infectious Diseases, Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Pathology & Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Shawn Babiuk
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB R3E 3M4, Canada;
- Department of Immunology, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
| | - Lorne Babiuk
- Vaccine and Infectious Disease Organization, University of Alberta, Edmonton, AB T6G 2G3, Canada;
| | - Jie Chen
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada;
- Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
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2
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Harris AR, Grayden DB, John SE. Electrochemistry in a Two- or Three-Electrode Configuration to Understand Monopolar or Bipolar Configurations of Platinum Bionic Implants. MICROMACHINES 2023; 14:722. [PMID: 37420955 DOI: 10.3390/mi14040722] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 07/09/2023]
Abstract
Electrodes are used in vivo for chemical sensing, electrophysiological recording, and stimulation of tissue. The electrode configuration used in vivo is often optimised for a specific anatomy and biological or clinical outcomes, not electrochemical performance. Electrode materials and geometries are constrained by biostability and biocompatibility issues and may be required to function clinically for decades. We performed benchtop electrochemistry, with changes in reference electrode, smaller counter-electrode sizes, and three- or two-electrode configurations. We detail the effects different electrode configurations have on typical electroanalytical techniques used on implanted electrodes. Changes in reference electrode required correction by application of an offset potential. In a two-electrode configuration with similar working and reference/counter-electrode sizes, the electrochemical response was dictated by the rate-limiting charge transfer step at either electrode. This could invalidate calibration curves, standard analytical methods, and equations, and prevent use of commercial simulation software. We provide methods for determining if an electrode configuration is affecting the in vivo electrochemical response. We recommend sufficient details be provided in experimental sections on electronics, electrode configuration, and their calibration to justify results and discussion. In conclusion, the experimental limitations of performing in vivo electrochemistry may dictate what types of measurements and analyses are possible, such as obtaining relative rather than absolute measurements.
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Affiliation(s)
- Alexander R Harris
- Department of Biomedical Engineering, University of Melbourne, Melbourne 3010, Australia
| | - David B Grayden
- Department of Biomedical Engineering, University of Melbourne, Melbourne 3010, Australia
- Graeme Clark Institute, University of Melbourne, Melbourne 3010, Australia
| | - Sam E John
- Department of Biomedical Engineering, University of Melbourne, Melbourne 3010, Australia
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3
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Wang M, Zhang Y, Bin J, Niu L, Zhang J, Liu L, Wang A, Tao J, Liang J, Zhang L, Kang X. Cold Laser Micro-Machining of PDMS as an Encapsulation Layer for Soft Implantable Neural Interface. MICROMACHINES 2022; 13:1484. [PMID: 36144107 PMCID: PMC9504264 DOI: 10.3390/mi13091484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/01/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
PDMS (polydimethylsiloxane) is an important soft biocompatible material, which has various applications such as an implantable neural interface, a microfluidic chip, a wearable brain-computer interface, etc. However, the selective removal of the PDMS encapsulation layer is still a big challenge due to its chemical inertness and soft mechanical properties. Here, we use an excimer laser as a cold micro-machining tool for the precise removal of the PDMS encapsulation layer which can expose the electrode sites in an implantable neural interface. This study investigated and optimized the effect of excimer laser cutting parameters on the electrochemical impedance of a neural electrode by using orthogonal experiment design. Electrochemical impedance at the representative frequencies is discussed, which helps to construct the equivalent circuit model. Furthermore, the parameters of the equivalent circuit model are fitted, which reveals details about the electrochemical property of neural electrode using PDMS as an encapsulation layer. Our experimental findings suggest the promising application of excimer lasers in the micro-machining of implantable neural interface.
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Affiliation(s)
- Minjie Wang
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Yuan Zhang
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | | | - Lan Niu
- Ji Hua Laboratory, Foshan 528200, China
| | - Jing Zhang
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Lusheng Liu
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Aiping Wang
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Jin Tao
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Jingqiu Liang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Lihua Zhang
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
- Ji Hua Laboratory, Foshan 528200, China
| | - Xiaoyang Kang
- Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
- Ji Hua Laboratory, Foshan 528200, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu 322000, China
- Research Center for Intelligent Sensing, Zhejiang Lab, Hangzhou 311100, China
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4
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Parylene C as an Insulating Polymer for Implantable Neural Interfaces: Acute Electrochemical Impedance Behaviors in Saline and Pig Brain In Vitro. Polymers (Basel) 2022; 14:polym14153033. [PMID: 35893997 PMCID: PMC9332801 DOI: 10.3390/polym14153033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/09/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022] Open
Abstract
Parylene is used as encapsulating material for medical devices due to its excellent biocompatibility and insulativity. Its performance as the insulating polymer of implantable neural interfaces has been studied in electrolyte solutions and in vivo. Biological tissue in vitro, as a potential environment for characterization and application, is convenient to access in the fabrication lab of polymer and neural electrodes, but there has been little study investigating the behaviors of Parylene in the tissue in vitro. Here, we investigated the electrochemical impedance behaviors of Parylene C polymer coating both in normal saline and in a chilled pig brain in vitro by performing electrochemical impedance spectroscopy (EIS) measurements of platinum (Pt) wire neural electrodes. The electrochemical impedance at the representative frequencies is discussed, which helps to construct the equivalent circuit model. Statistical analysis of fitted parameters of the equivalent circuit model showed good reliability of Parylene C as an insulating polymer in both electrolyte models. The electrochemical impedance measured in pig brain in vitro shows marked differences from that of saline.
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5
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Evers J, Sridhar K, Liegey J, Brady J, Jahns H, Lowery M. Stimulation-induced changes at the electrode-tissue interface and their influence on deep brain stimulation. J Neural Eng 2022; 19. [PMID: 35728575 DOI: 10.1088/1741-2552/ac7ad6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/21/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE During deep brain stimulation (DBS) the electrode-tissue interface forms a critical path between device and brain tissue. Although changes in the electrical double layer and glial scar can impact stimulation efficacy, the effects of chronic DBS on the electrode-tissue interface have not yet been established. APPROACH In this study, we characterised the electrode-tissue interface surrounding chronically implanted DBS electrodes in rats and compared the impedance and histological properties at the electrode interface in animals that received daily stimulation and in those where no stimulation was applied, up to eight weeks post-surgery. A computational model was developed based on the experimental data, which allowed the dispersive electrical properties of the surrounding encapsulation tissue to be estimated. The model was then used to study the effect of stimulation-induced changes in the electrode-tissue interface on the electric field and neural activation during voltage- and current-controlled stimulation. MAIN RESULTS Incorporating the observed changes in simulations in silico, we estimated the frequency-dependent dielectric properties of the electrical double layer and surrounding encapsulation tissue. Through simulations we show how stimulation-induced changes in the properties of the electrode-tissue interface influence the electric field and alter neural activation during voltage-controlled stimulation. A substantial increase in the number of stimulated collaterals, and their distance from the electrode, was observed during voltage-controlled stimulation with stimulated ETI properties. In vitro examination of stimulated electrodes confirmed that high frequency stimulation leads to desorption of proteins at the electrode interface, with a concomitant reduction in impedance. SIGNIFICANCE The demonstration of stimulation-induced changes in the electrode-tissue interface has important implications for future DBS systems including closed-loop systems where the applied stimulation may change over time. Understanding these changes is particularly important for systems incorporating simultaneous stimulation and sensing, which interact dynamically with brain networks.
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Affiliation(s)
- J Evers
- School of Electrical and Electronic Engineering, University College Dublin, Engineering Building, UCD Belfield, Dublin, Dublin, 4, IRELAND
| | - K Sridhar
- School of Electrical and Electronic Engineering, University College Dublin, Engineering Building, UCD Belfield, Dublin, Dublin, 4, IRELAND
| | - J Liegey
- School of Electrical and Electronic Engineering, University College Dublin, Engineering Building, UCD Belfield, Dublin, Dublin, 4, IRELAND
| | - J Brady
- School of Veterinary Medicine, University College Dublin, Veterinary Science Center, Dublin, 4, IRELAND
| | - H Jahns
- School of Veterinary Medicine, University College Dublin, Veterinary Science Center, Dublin, 4, IRELAND
| | - M Lowery
- School of Electrical, Electronic & Mechancial Engineering, University College Dublin, Engineering & Materials Science Centre, Belfield, Dublin 4, Dublin, 4, IRELAND
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6
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Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes. MICROMACHINES 2022; 13:mi13010103. [PMID: 35056268 PMCID: PMC8779563 DOI: 10.3390/mi13010103] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/14/2021] [Accepted: 01/04/2022] [Indexed: 12/13/2022]
Abstract
The electrochemical performance of platinum electrodes was assessed in vitro and in vivo to determine the impact of electrode implantation and the relevance of in vitro testing in predicting in vivo behaviour. A significant change in electrochemical response was seen after electrode polarisation. As a result, initial in vitro measurements were poor predictors of subsequent measurements performed in vitro or in vivo. Charge storage capacity and charge density measurements from initial voltammetric measurements were not correlated with subsequent measurements. Electrode implantation also affected the electrochemical impedance. The typically reported impedance at 1 kHz was a very poor predictor of electrode performance. Lower frequencies were significantly more dependent on electrode properties, while higher frequencies were dependent on solution properties. Stronger correlations in impedance at low frequencies were seen between in vitro and in vivo measurements after electrode activation had occurred. Implanting the electrode increased the resistance of the electrochemical circuit, with bone having a higher resistivity than soft tissue. In contrast, protein fouling and fibrous tissue formation had a minimal impact on electrochemical response. In vivo electrochemical measurements also typically use a quasi-reference electrode, may operate in a 2-electrode system, and suffer from uncompensated resistance. The impact of these experimental conditions on electrochemical performance and the relevance of in vitro electrode assessment is discussed. Recommended in vitro testing protocols for assessing bionic electrodes are presented.
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7
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Pitsalidis C, Pappa AM, Boys AJ, Fu Y, Moysidou CM, van Niekerk D, Saez J, Savva A, Iandolo D, Owens RM. Organic Bioelectronics for In Vitro Systems. Chem Rev 2021; 122:4700-4790. [PMID: 34910876 DOI: 10.1021/acs.chemrev.1c00539] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bioelectronics have made strides in improving clinical diagnostics and precision medicine. The potential of bioelectronics for bidirectional interfacing with biology through continuous, label-free monitoring on one side and precise control of biological activity on the other has extended their application scope to in vitro systems. The advent of microfluidics and the considerable advances in reliability and complexity of in vitro models promise to eventually significantly reduce or replace animal studies, currently the gold standard in drug discovery and toxicology testing. Bioelectronics are anticipated to play a major role in this transition offering a much needed technology to push forward the drug discovery paradigm. Organic electronic materials, notably conjugated polymers, having demonstrated technological maturity in fields such as solar cells and light emitting diodes given their outstanding characteristics and versatility in processing, are the obvious route forward for bioelectronics due to their biomimetic nature, among other merits. This review highlights the advances in conjugated polymers for interfacing with biological tissue in vitro, aiming ultimately to develop next generation in vitro systems. We showcase in vitro interfacing across multiple length scales, involving biological models of varying complexity, from cell components to complex 3D cell cultures. The state of the art, the possibilities, and the challenges of conjugated polymers toward clinical translation of in vitro systems are also discussed throughout.
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Affiliation(s)
- Charalampos Pitsalidis
- Department of Physics, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi 127788, UAE.,Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Anna-Maria Pappa
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi 127788, UAE
| | - Alexander J Boys
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Ying Fu
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K.,Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow G1 1RD, U.K
| | - Chrysanthi-Maria Moysidou
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Douglas van Niekerk
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Janire Saez
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K.,Microfluidics Cluster UPV/EHU, BIOMICs Microfluidics Group, Lascaray Research Center, University of the Basque Country UPV/EHU, Avenida Miguel de Unamuno, 3, 01006 Vitoria-Gasteiz, Spain.,Ikerbasque, Basque Foundation for Science, E-48011 Bilbao, Spain
| | - Achilleas Savva
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Donata Iandolo
- INSERM, U1059 Sainbiose, Université Jean Monnet, Mines Saint-Étienne, Université de Lyon, 42023 Saint-Étienne, France
| | - Róisín M Owens
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
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8
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Schiavone G, Kang X, Fallegger F, Gandar J, Courtine G, Lacour SP. Guidelines to Study and Develop Soft Electrode Systems for Neural Stimulation. Neuron 2020; 108:238-258. [PMID: 33120021 DOI: 10.1016/j.neuron.2020.10.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/23/2020] [Accepted: 10/08/2020] [Indexed: 12/13/2022]
Abstract
Electrical stimulation of nervous structures is a widely used experimental and clinical method to probe neural circuits, perform diagnostics, or treat neurological disorders. The recent introduction of soft materials to design electrodes that conform to and mimic neural tissue led to neural interfaces with improved functionality and biointegration. The shift from stiff to soft electrode materials requires adaptation of the models and characterization methods to understand and predict electrode performance. This guideline aims at providing (1) an overview of the most common techniques to test soft electrodes in vitro and in vivo; (2) a step-by-step design of a complete study protocol, from the lab bench to in vivo experiments; (3) a case study illustrating the characterization of soft spinal electrodes in rodents; and (4) examples of how interpreting characterization data can inform experimental decisions. Comprehensive characterization is paramount to advancing soft neurotechnology that meets the requisites for long-term functionality in vivo.
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Affiliation(s)
- Giuseppe Schiavone
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, 1202 Geneva, Switzerland
| | - Xiaoyang Kang
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, 1202 Geneva, Switzerland
| | - Florian Fallegger
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, 1202 Geneva, Switzerland
| | - Jérôme Gandar
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Grégoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; Defitech Center for Interventional Neurotherapies (NeuroRestore), Department of Neurosurgery, University Hospital of Lausanne (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Stéphanie P Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, 1202 Geneva, Switzerland.
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9
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González‐Sánchez MI, Romero‐Llapa MI, Gómez‐Monedero B, Jiménez‐Pérez R, Iniesta J, Valero E. A Fast and Simple Ozone‐mediated Method towards Highly Activated Screen Printed Carbon Electrodes as Versatile Electroanalytical Tools. ELECTROANAL 2019. [DOI: 10.1002/elan.201900335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- María Isabel González‐Sánchez
- Department of Physical Chemistry, Higher Technical School of Industrial EngineeringUniversity of Castilla-La Mancha, Campus Universitario s/n 02071 Albacete Spain
| | - María Isabel Romero‐Llapa
- Department of Physical Chemistry, Higher Technical School of Industrial EngineeringUniversity of Castilla-La Mancha, Campus Universitario s/n 02071 Albacete Spain
| | - Beatriz Gómez‐Monedero
- Department of Physical Chemistry, Higher Technical School of Industrial EngineeringUniversity of Castilla-La Mancha, Campus Universitario s/n 02071 Albacete Spain
| | - Rebeca Jiménez‐Pérez
- Department of Physical Chemistry, Higher Technical School of Industrial EngineeringUniversity of Castilla-La Mancha, Campus Universitario s/n 02071 Albacete Spain
| | - Jesús Iniesta
- Department of Physical Chemistry and Institute of ElectrochemistryUniversity of Alicante 03690, San Vicente del Raspeig, Alicante Spain
| | - Edelmira Valero
- Department of Physical Chemistry, Higher Technical School of Industrial EngineeringUniversity of Castilla-La Mancha, Campus Universitario s/n 02071 Albacete Spain
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10
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Harris AR, Allitt BJ, Paolini AG. Predicting neural recording performance of implantable electrodes. Analyst 2019; 144:2973-2983. [PMID: 30888346 DOI: 10.1039/c8an02214c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recordings of neural activity can be used to aid communication, control prosthetic devices or alleviate disease symptoms. Chronic recordings require a high signal-to-noise ratio that is stable for years. Current cortical devices generally fail within months to years after implantation. Development of novel devices to increase lifetime requires valid testing protocols and a knowledge of the critical parameters controlling electrophysiological performance. Here we present electrochemical and electrophysiological protocols for assessing implantable electrodes. Biological noise from neural recording has significant impact on signal-to-noise ratio. A recently developed surgical approach was utilised to reduce biological noise. This allowed correlation of electrochemical and electrophysiological behaviour. The impedance versus frequency of modified electrodes was non-linear. It was found that impedance at low frequencies was a stronger predictor of electrophysiological performance than the typically reported impedance at 1 kHz. Low frequency impedance is a function of electrode area, and a strong correlation of electrode area with electrophysiological response was also seen. Use of these standardised testing protocols will allow future devices to be compared before transfer to preclinical and clinical trials.
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Affiliation(s)
- Alexander R Harris
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, NSW 2522, Australia.
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11
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Inal S, Hama A, Ferro M, Pitsalidis C, Oziat J, Iandolo D, Pappa AM, Hadida M, Huerta M, Marchat D, Mailley P, Owens RM. Conducting Polymer Scaffolds for Hosting and Monitoring 3D Cell Culture. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/adbi.201700052] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Sahika Inal
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
- Biological and Environmental Science and Engineering; King Abdullah University of Science and Technology (KAUST); Thuwal 23955-6900 Kingdom of Saudi Arabia
| | - Adel Hama
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Magali Ferro
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Charalampos Pitsalidis
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Julie Oziat
- CEA; LETI; MINATEC Campus; 38054 Grenoble France
| | - Donata Iandolo
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Anna-Maria Pappa
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Mikhael Hadida
- Laboratoire Sainbiose; Ecole Nationale Supérieure des Mines; CIS-EMSE; St. Etienne 42023 France
| | - Miriam Huerta
- Department of Infectomics and Molecular Pathogenesis; Cinvestav 14-740, 070000 Mexico
| | - David Marchat
- Laboratoire Sainbiose; Ecole Nationale Supérieure des Mines; CIS-EMSE; St. Etienne 42023 France
| | | | - Róisín M. Owens
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
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12
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Harris AR, Paolini AG. Correlation of Impedance and Effective Electrode Area of Iridium Oxide Neural Electrodes. Aust J Chem 2017. [DOI: 10.1071/ch17218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Iridium oxide is routinely used for bionic applications owing to its high charge injection capacity. The electrode impedance at 1 kHz is typically reported to predict neural recording performance. In this article, the impedance of activated iridium oxide films (AIROFs) has been examined. The impedance of unactivated iridium electrodes was half that of platinum electrodes of similar geometry, indicating some iridium oxide was present on the electrode surface. A two time constant equivalent circuit was used to model the impedance of activated iridium. The impedance at low and intermediate frequencies decreased with increasing number of activation pulses and total activation charge. The impedance at 12 Hz correlated with the steady-state diffusion electroactive area. The impedance at 12 Hz also correlated with the charge density of the electrode. The high charge density and low impedance of AIROFs may provide improved neural stimulation and recording properties compared with typically used platinum electrodes.
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