Flexible Carbon Fiber/TiO₂ Nanopillars Electrode in the Detection of Glucose Under Photoexcitation

Abstract

The development and utilization of biosensors have received a great attention from the scientific community due to their wide applications in the areas of food safety, medical diagnosis, environmental monitoring and other fields. In this paper, we report the development of a novel photoelectrochemical (PEC) sensor for glucose detection using a flexible carbon fiber/TiO2 nanopillars electrode. The carbon fiber/TiO2 nanopillars was prepared by two step process in which the first step is to grow TiO2 seeds over carbon fiber by magnetron sputtering while the second step leads the growth of TiO2 nanopillars over flexible carbon fibers substrate. Under photoexcitation, the PEC sensor showed a significant enhancement in the sensitivity for glucose detection. The detection mechanism was based on the photoelectrochemical oxidation of glucose to gluconic acid, which generated an electrical signal that was proportional to the glucose concentration. The electrochemical examinations were performed at low glucose concentrations in the range of 1–5 mM (mmol L−1) to investigate the corresponding photocurrent. The results showed that the photocurrent increases with increasing the glucose concentration. This is of great significance for the detection of hypoglycemia, and has good application prospects in the fields of nano-detection, biological diagnosis and wearable devices. The flexible carbon fiber/TiO2 PEC sensor developed in this study is a promising approach for the development of wearable devices for continuous glucose monitoring.