Fabrication of layered double hydroxide/sepiolite composite as an effective electrocatalyst for glucose determination in sport drinks

In this study, ultrathin CuAl layered double hydroxide (LDH) nanosheets were successfully deposited on sepiolite clay (SPC) support and used as an effective electrocatalyst for fabrication of a new non-enzymatic glucose sensor. According to a series of electrochemical results, the growth of CuAl LDH on SPC decreases the charge-transfer resistance in the surface of modified carbon paste electrode (CPE). At an optimum potential of + 0.40 V, the CuAl LDH/SPC modified CPE depicted a wide linear range over a concentration of 0.1 to 1450 µM with a detection limit of 0.03 µM (S/N = 3). Significantly, the established assay demonstrated a strong resistance to interference from common substances such as fructose, valine, ascorbic acid, urea, L-cysteine, and uric acid. The suggested assay was successfully employed to detect glucose in sport drinks with satisfactory results. The modified electrode with CuAl LDH/SPC presents improved electro-catalytic properties, operating at a lower working potential. It demonstrates rapid response, high stability, and reproducibility in the oxidation of glucose. These features make it a promising candidate for the development of non-enzymatic glucose sensors in the future.