Colloidal SnO₂ nanoparticles for the enhancement of PEDOT:PSS-coated string electrodes for potential use for glucose sensing

As the healthcare industry continues to evolve its approach to monitoring patient health, the growing need for rapid accurate biosensing in a wearable device is becoming more and more relevant. Along with size, weight, and various technology constraints, making a nanoscale biosensor can be beneficial in furthering this exploratory venture. In this work, string-shaped electrodes have been fabricated by coating PEDOT:PSS on commercially available threads. Some of the electrodes were further coated with a solution containing SnO₂ nanoparticles. By immobilizing glucose oxidase (GOx) on the strings, the electrodes were electrochemically characterized when they were exposed to the electrolytes containing glucose. The cyclic voltammetry and electrochemical impedance spectroscopy results show that the presence of NPs has a significant effect on electrochemical response of the electrodes particularly after the immobilization of GOx. The chronoamperometry (CA) studies of the two electrodes verifiy the impact of NPs in the sensitivity of the electrodes reaching 83.70 µA/mMcm². The promising results from this work encourage designing wearable sensors with the string-shaped electrodes coated with SnO2 nanoparticles for future wearable sensors.