Study of the application of a Cu2O thin film as non-enzymatic amperometric glucose sensor

The detection and control of glucose (Glu) levels in both food and biological samples have gained importance in recent decades, as imbalances in glucose levels can lead to health complications such as diabetes mellitus. Consequently, this study focused on synthesizing thin films of Cu2O and evaluating their application as a non-enzymatic amperometric glucose sensor. The Cu2O films were obtained on FTO at a constant potential (-0.575 V vs. SMSE), in an inert atmosphere and at room temperature. The electrolyte solution consisted of 0.02 M of copper acetate (Cu(OOCCH3)(2)) and 0.1 M of sodium acetate (NaOOCCH3) at pH 5.79, in a three-electrode cell. The films obtained were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the other hand, the electrocatalytic activity was studied using linear potential sweep (LPS) and chronoamperometry (CA) techniques. From these techniques, it was possible to determine the sensitivity (228.1 mu A mM(-1) cm(-2)), limit of detection (LOD 2.49 x 10(-3) mM), limit of quantification (LOQ 7.54 x 10(-3) mM) and linear range (0.10 mM <=[Glucose] <= 15 mM). In this concentration interval the response time was between 1.4 and 14 s. It was established that the sensor exhibits minimal response to various electroactive interferences and demonstrates reproducibility and stability over time. In this way, the proposed Cu2O electrode is a good candidate to be used as a non-enzymatic amperometric glucose sensor.