Light-Assisted Batch Injection Analysis of Glucose Exploiting a p-n-Homojunction Based on Cu₂O

This work describes the development of a photoelectrochemical sensor for glucose quantification exploiting a light assisted-batch injection analysis (BIA) cell. A light-emitting diode (LED) lamp was employed to control the incidence of light on the p-Cu₂O/n-Cu₂O/fluorine-doped tin oxide (FTO) photoactive platform in BIA cell. The p-Cu₂O/n-Cu₂O/FTO platform was constructed by electrodepositing n-Cu₂O and p-Cu₂O and the characteristics of electrodeposited Cu₂O films were investigated by X-ray diffraction (XRD), Raman spectroscopy, and electrochemical impedance spectroscopy. The light assisted-batch injection analysis of glucose based on the illuminated p-Cu₂O/n-Cu₂O/FTO photoelectrode presented a linear response of 10 μmol L^-1-1 mmol L^-1, a limit of detection of 4.0 μmol L^-1, and sensitivity of 0.768 ± 0.011 μA L μmol^-1 cm^-2. The system presented an average recovery value of 96% when applied to the determination of glucose in an artificial saliva sample, which indicates that the incidence of light on photoelectroactive platforms is a promising approach for the determination and quantification of glucose.

Keywords:
batch injection analysis; copper(II) oxide; glucose; LED light