Developing low-cost and multiplexing electrochemical (EC) devices for bioassay is imperative. Herein, a polymer-based EC device, named EC 6-well plate, was proposed and fabricated using a non-photolithography method. Polyethylene terephthalate glycol (PETG) was used as a substrate and laser-cut polyester (PET) film was used as a mask for patterning the electrodes. The diameter of the working electrode (WE) was 900 μ m, and each WE-modifying step only requires 1 μ l of reagent. Acrylic mold with wells (60 μ l) was bonded to the PETG substrate. Miniaturization of reference electrodes (RE) was discussed. The solid-state Ag/AgCl RE-based three-electrode system, the Au three-electrode system (3E), and Au two-electrode system (2E) were prepared and employed to develop an immunosensor for toxin B detection. Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were applied to test the stability of the EC immunosensor. The solid-state Ag/AgCl RE-based system showed a standard deviation of open circuit potential (OCP) of 4.6 mV. The 3E system and 2E system showed the standard deviations of OCP of 0.0026 mV and 0.32 mV, respectively. It revealed that the EC 6-well plate with the 3E system is excellent for developing an EC immunosensor.
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Electrochemical performance study of Ag/AgCl and Au flexible electrodes for unobtrusive monitoring of human biopotentials
Flexible and stretchable electronics are a logical choice for the recording of biopotentials, due to their improved patient comfort and customizability. There is, however, significant variance in the signal quality received from these electrodes based on material, size, and target recording frequency. Here we develop a methodology based on Electrochemical Impedance Spectroscopy (EIS) and circuit modeling for optimizing electrodes for a specific application. We use EIS to measure the frequency dependent impedance characteristics of gold (Au) and silver/silver chloride (Ag/AgCl) electrodes of different diameters. Additionally, we use a Randles circuit model and perform model fitting with our data to extrapolate results to arbitrary frequencies and diameters. We found that at low frequencies (<1 Hz), Ag/AgCl had lower overall magnitude impedance than Au and at higher frequencies (1–1000 Hz), Au and Ag/AgCl performed similarly. Further, the magnitude impedance of the electrodes decreased linearly as electrode diameter increased. The methodology described in this study can be applicable to any customizable stretchable electronics fabrication process and enables design optimization for a target frequency, electrode size, and material.
more » « less- NSF-PAR ID:
- 10369420
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Nano Select
- Volume:
- 3
- Issue:
- 8
- ISSN:
- 2688-4011
- Page Range / eLocation ID:
- p. 1277-1287
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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