skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Development of Electrochemical 6-Well Plates and Its Stability as an Immunosensor
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.  more » « less
Award ID(s):
1805514
PAR ID:
10357433
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Journal of The Electrochemical Society
Volume:
169
Issue:
2
ISSN:
0013-4651
Page Range / eLocation ID:
027506
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, Frontiers in Electronics)
    With the rising need for on-body biometric sensing, the development of wearable electrophysiological sensors has been faster than ever. Surface electrodes placed on the skin need to be robust in order to measure biopotentials from the body reliably and comfortable for extended wearability. The electrical stability of nonpolarizable silver/silver chloride (Ag/AgCl) and its low-cost, commercial production have made these electrodes ubiquitous health sensors in the clinical environment, where wet gels and long wires are accommodated by patient immobility. However, smaller, dry electrodes with wireless acquisition are essential for truly wearable, continuous health sensing. Currently, techniques for the robust fabrication of custom Ag/AgCl electrodes are lacking. Here, we present three methods for the fabrication of Ag/AgCl electrodes: oxidizing Ag in a chlorine solution, electroplating Ag, and curing Ag/AgCl ink. Each of these methods is then used to create three different electrode shapes for wearable application. Bench-top and on-body evaluation of the electrode techniques was achieved by electrochemical impedance spectroscopy (EIS), calculation of variance in electrocardiogram (ECG) measurements, and analysis of auditory steady-state response (ASSR) measurement. Microstructures produced on the electrode by each fabrication technique were also investigated with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The custom Ag/AgCl electrodes were found to be efficient in comparison with standard, commercial Ag/AgCl wet electrodes across all three of our presented techniques, with Ag/AgCl ink shown to be the better out of the three in bench-top and biometric recordings. 
    more » « less
  2. ; ; ; (, ChemElectroChem)
    Abstract Gold screen printed electrodes (Au‐SPEs) were treated electrochemically to produce a micro‐rough pattern increasing the real electrode surface. The procedure based on the Dynamic Hydrogen Bubble Template (DHBT) method included electrochemical deposition of Au layers onto the surface of the Au‐SPEs, followed by a reductive process at −3 V (vs. Ag/AgCl) leading to formation of H2bubbles, which produced pores in the Au multilayer. The morphology of the micro‐porous Au electrode was characterized by scanning electron microscopy (SEM), surface mapping, surface profilometry, and confocal microscopy. The electrode surface morphology was controlled by the time of the electrode reductive treatment (H2evolution) and the optimized condition resulting in the best surface structuring was found. Notably, the surface roughness leading to the highest electrode surface area was significantly increased compared to previously reported results with Au‐SPEs. 
    more » « less
  3. ; ; ; ; ; (, Electroanalysis)
    Abstract The electrochemical detection of two pharmaceuticals, diclofenac (DCF) and carbamazepine (CBZ), was investigated as an oxidation current using boron‐doped nanocrystalline diamond (BDD) thin‐film electrodes. Both voltammetry and flow injection analysis with amperometric detection (FIA‐EC) were used to measure the drugs in standard solutions and a urine simulant. The oxidation potential for DCF wasca. 0.7 V vs. Ag/AgCl (3 M KCl) in 0.1 M phosphate buffer (pH 7.2) and wasca. 1.2 V for CBZ in 0.1 M perchloric acid. The DCF oxidation reaction was diffusion controlled at the detection potential with evidence of some surface fouling by reaction products. The CBZ oxidation reaction was also controlled by diffusion at the detection potential, but with no surface fouling. The voltammetric peak currents for both drugs increased linearly with the concentration in the micromolar range (r2≥0.994). FIA‐EC analysis of DCF and CBZ revealed a linear dynamic range from at least 0.1 to 100 μM with the actual minimum concentration detectable (S/N=3) being less than the lowest concentration measured. The recovery percentage for DCF in the urine simulant ranged from 94–108% and from 97–100% for CBZ, both assessed using square wave voltammetry. FIA‐EC data revealed that the BDD electrodes offer excellent intra and inter‐electrode repeatability with an RSD for DCF and CBZ of 4.90% and 3.81%, respectively. The BDD electrode provided good reproducibility and response stability over eight days of continuous use detecting both DCF and CBZ. Overall, BDD electrodes are a viable material  for the sensitive, selective, and reproducible electrochemical detection of these two pharmaceuticals. 
    more » « less
  4. ; ; ; ; ; ; (, Environmental Science: Advances)
    Electrochemical (EC) and photoelectrochemical (PEC) water treatment systems are gaining popularity, necessitating new electrode materials that offer reliable performance across diverse application platforms. For applications specifically targeting dilute chemical pollutants ( i.e. , parts-per-million concentrations or less), beneficial electrode properties include high surface area to overcome kinetic overpotential losses, low electrode areal electrical resistance, and high water permeability with sufficient mechanical strength for use in electroactive membrane-based treatment systems. Here, we used electrospinning to fabricate (photo)electrodes from carbon nanofibers (CNFs) containing titanium dioxide (TiO 2 ) nanoparticles. Optimal CNF/TiO 2 composites were electrochemically and photochemically active with a surface area of ∼50 m 2 g −1 and electrode areal resistance of 2.66 Ω cm 2 , values comparable to commercial carbon-based electrode materials ( e.g. , Kynol Activated Carbon Cloth). Transformation experiments with carbamazepine (CBZ), a recalcitrant organic contaminant, suggest CNF/TiO 2 electrodes function dually as sorbents, first binding CBZ prior to oxidation at positive applied potentials. Complete CBZ transformation was observed in both EC (dark) and PEC (UV light; 280 mW cm −2 ) systems over 90 minutes, with PEC systems exhibiting 1.5-fold higher transformation rates ( k obs ∼ 0.18 min −1 ) at +1.00 V ( vs. Ag/AgCl). Composite electrodes also exhibited stability across repeated use, yielding consistent current densities over five experimental cycles (120 min each) of CBZ transformation (0.25 ± 0.03 mA cm −2 ). Because of their high surface area, electrical conductivity, photoactivity, and electrochemical stability, these electrospun CNF/TiO 2 composites represent promising (photo)electrode alternatives for diverse EC and PEC applications. 
    more » « less
  5. ; ; (, Chemosensors)
    We built an integrated solid-contact ion-selective electrode (SCISE) system with the functionality of self-calibration. A multiplexed SCISE sensor (K+ and NO3− vs. Ag/AgCl) was fabricated on printed-circuit board (PCB) substrates and was subsequently embedded into a microfluidic flow cell for self-calibration and flow-through analysis. A PCB circuit that includes modules for both sensor readout and fluid control was developed. The sensors showed a fast and near-Nernstian response (56.6 for the K+ electrode and −57.4 mV/dec for the NO3− electrode) and maintained their performance for at least three weeks. The sensors also showed a highly reproducible response in an automated two-point calibration, demonstrating the potential for in situ monitoring. Lastly, the sensor system was successfully applied to measure mineral nutrients in plant sap samples. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email