Electrochemical detection of ascorbic acid in artificial sweat using a flexible alginate/CuO-modified electrode

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

A flexible sensor is presented for electrochemical detection of ascorbic acid in sweat based on single-step modified gold microelectrodes. The modification consists of electrodeposition of alginate membrane with trapped CuO nanoparticles. The electrodes are fabricated at a thin polyimide support and the soft nature of the membrane can withstand mechanical stress beyond requirements for skin monitoring. After characterization of the membrane via optical and scanning electron microscopy and cyclic voltammetry, the oxidative properties of CuO are exploited toward ascorbic acid for amperometric measurement at micromolar levels in neutral buffer and acidic artificial sweat, at ultralow applied potential (− 5 mV vs. Au pseudo-reference electrode). Alternatively, measurement of the horizontal shift of redox peaks by cyclic voltammetry is also possible. Obtaining a limit of detection of 1.97 μM, sensitivity of 0.103 V log (μM)−1 of peak shift, and linear range of 10–150 μM, the effect of possible interfering species present in sweat is minimized, with no observable cross-reaction, thus maintaining a high degree of selectivity despite the absence of enzymes in the fabrication scheme. With a lateral flow approach for sample delivery, repeated measurements show recovery in few seconds, with relative standard deviation of about 20%, which can serve to detect increased loss or absence of vitamin, and yet be improved in future by optimized device designs. This sensor is envisioned as a promising component of wearable devices for e.g. non-invasive monitoring of micronutrient loss through sweat, comprising features of light weight, low cost, and easy fabrication needed for such application. [Figure not available: see fulltext.]

Details

Original languageEnglish
Article number520
JournalMicrochimica acta : an international journal on micro and trace analysis
Volume187
Issue number9
Publication statusPublished - 1 Sept 2020
Peer-reviewedYes

External IDs

PubMed 32856149
ORCID /0000-0002-9899-1409/work/142249217

Keywords

ASJC Scopus subject areas

Keywords

  • Ascorbic acid, CuO nanoparticles, Electroanalysis, Nonenzymatic sensor