Miniaturized Carbon-Cloth/TiO2Nanofiber-Based Electrochemical Sensor for Simultaneous Detection of Dopamine and Insulin

Abstract

A plug-and-play, structurally sound electrochemical device, is necessary for the simultaneous detection of dopamine (DA) and insulin to facilitate real-time health monitoring and optimal diabetes treatment. This research investigates the application of carbon cloth (CC)/TiO2 nanofiber-based substrates as a sensitive surface for both. The well separated and simultaneous detection of DA and insulin is enabled by their distinct electrochemical oxidation mechanisms and differential surface interactions on the CC/TiO2 nanofiber substrate, where the small DA molecule undergoes rapid diffusion-controlled electron transfer, while the larger insulin molecule exhibits adsorption-assisted kinetics at higher oxidation potentials. Herein, the response of biosensors to different scan rates and increased analyte concentrations has been analyzed using electrochemical techniques cyclic voltammetry (CV) and chronoamperometry (CA). The results showed a linear increase in current with increasing DA and insulin concentrations, confirming high sensitivity and highly efficient electrocatalytic activity. The modified CC/TiO2 substrates showed superior performance compared to bare CC, confirming their enhanced detection capabilities. The successful modification of the substrate is confirmed by implementing a detailed characterization that was carried out besides various techniques, such as FTIR, XPS, and morphological studies, as well as results obtained from the electrochemical measurements using K3Fe(CN)6 supporting electrolyte. This sensor could be a potential candidate in biomolecule detection and personalized healthcare monitoring due to its biocompatibility, low cost, and high sensitivity.