Author ORCID Identifier:
Date of Graduation
5-2026
Document Type
Thesis
Degree Name
Master of Science in Chemistry (MS)
Degree Level
Graduate
Department
Chemistry & Biochemistry
Advisor/Mentor
Fritsch, Ingrid
Committee Member
Dong, Bin
Second Committee Member
Stenken, Julie
Keywords
Electrochemistry; Generation-Collection; Microband Electrode Arrays; Redox Monitoring
Abstract
Snapshot redox cycling voltammetry (Snapshot RCV) is introduced as a rapid electrochemical technique that reconstructs the current-potential profile of a redox active species using a microband electrode array. By simultaneously biasing individual generator electrodes alternating in the array to different voltages across the analyte’s potential range while individually holding collector electrodes at a reversing potential, “spatial” voltammetry is achieved in as little as 1 s with the temporal speed of chronoamperometry, rapidly capturing the steady-state redox cycling (RC) profiles. During RC (a mode of generation-collection), the analyte is oxidized (or reduced) at generator electrodes and converted back at neighboring collector electrodes held at a constant potential, yielding two current signals. This reveals information about diffusion-dominated systems, heterogeneous electron transfer kinetics, and following chemical reactions. Furthermore, as electrode spacing decreases, current amplifies from overlapping diffusion layers that increase concentration gradients. In contrast to conventional RC voltammetry (Conventional RCV) that slowly sweeps the generator potential, Snapshot RCV applies a distribution of potentials across individual generator electrodes instead. Snapshot RCV was validated using 0.50 mM Ru(NH3)6Cl3 in 0.10 M KCl on a seven-electrode subset of a nine-electrode gold microband chip, (NE = 7, w = 4.08 µm, wgap = 4.14 µm, length = 97.17 µm). Snapshot RCV was then applied to pure solutions of 0.50 mM dopamine (DA), 3,4-dihydroxyphenylalanine (L-DOPA), 3,4-dihydroxyphenylacetic acid (DOPAC), and ascorbic acid (AA) in artificial cerebral spinal fluid (aCSF). This applies the technique to systems where subsequent chemical reactions lower collection efficiency (DA, L-DOPA, DOPAC), or where irreversible products are generated (AA). Snapshot RCV is shown to capture the voltammetric shape for the electrochemical behavior of the analyte with an increase in collection efficiency by 10%-60% over Conventional RCV. This distinction in collection efficiencies and response shapes of biologically relevant molecules, driven by their thermodynamics, kinetics, and following chemical mechanisms could make Snapshot RCV a promising qualitative and quantitative technique, enabling rapid sensing in confined spaces.
Citation
Sterling, B. A. (2026). Advancement in Electrochemical Generation-Collection: Snapshot Redox Cycling Voltammetry for Rapid Analysis at Chip-Based, Individually Addressable Microband Electrode Arrays. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6151
