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

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.

Solanum tuberosum Leaf Extract Templated Synthesis of Co3O4 Nanoparticles for Electrochemical Sensor and Antibacterial Applications

“…It has been seen that metal oxide nanoparticles having high surface area to volume ratio with fast electron transfer kinetics are around to be the best candidates for decorating the bare electrode surface for the measurement and detection of ascorbic acid levels in various sources [ 12 ]. Various metal oxide nanoparticles (NPs) such as ZnO, CuO, Fe 3 O 4 , Ag, Cu, Co 3 O 4 , TiO 2 , MgO, and MnO 2 were synthesized by various methods and used as chemical sensors, biosensors, and gas sensors in the field of industries, environment, food, and drinking items [ 13 – 18 ].…”

Design and Development of Advanced Glucose Biosensors via Tuned Interactions between Marine Polysaccharides and Diagnostic Elements – A Survey

“…Surprisingly, an extensive literature survey revealed no studies in the past decade on non-enzymatic sensors based on alginate for glucose detection. While it may be tempting to believe that this lack of information points toward an incompatibility between alginate and non-enzymatic biosensing elements, this supposition is not true as there are a number of reports on alginate and non-enzymatic systems for monitoring other biomarkers like urea [50], ascorbic acid [51], and H2O2 [52]. For example, as demonstrated in Section 3.2, RGO is a felicitous material for non-enzymatic sensors based on chitosan and these characteristics may be combined with alginate as well without the need for complex systems (owing to the functionalization potential of alginate).…”

Electrochemical Detection of Ascorbic Acid in Oranges at MWCNT-AONP Nanocomposite Fabricated Electrode

“…They require longer sample preparation, are time-consuming; moreover, others need laboratory equipment, except for electrochemical technique [26,27]. Electrochemical sensors fabricated with carbon nanotubes (CNTs), metal oxide nanoparticles, and graphene oxide and conducting polymers have been used extensively to detect AA in different real-life samples [28][29][30][31][32][33][34][35]. These sensors are found to be affordable, offer quick and efficient analysis, and offers highly sensitive and selective.…”