Ag₂Te/g-C₃N₄/GS nanocomposite-based ultrasensitive electrochemical sensor for selective detection of dapagliflozin

Abstract

Dapagliflozin (DAPA) is a drug in the gliflozin class, a hypoglycemic agent that lowers blood glucose by suppressing sodium-glucose co-transporters in the kidneys, reducing glucose reabsorption. In the present study, a novel ultrasensitive and cost-effective Ag₂Te/g-C₃N₄/GS electrochemical sensor was designed for the detection of DAPA. Ag2Te/g-C3N4 (ATG) nanocomposites were fabricated via a solution phase chemical reduction method with different compositions of g-C3N4 (20, 30, and 50 wt%). The crystallite size was analyzed using XRD and was 5.5 nm for g-C₃N₄, 18 nm for Ag/g-C₃N₄, and 16 nm for Te/g-C₃N₄. Notably, the Ag₂Te/g-C₃N₄ composite exhibited a 13 nm reduction in crystallite size. The FE-SEM revealed the morphology of the ATG nanocomposites, which reveals the uniform distribution of Ag₂Te nanostructures on the g-C₃N₄ nanosheets. The ATG nanocomposite was uniformly distributed over a graphite sheet (GS), and a simple, eco-friendly, and sensitive Ag₂Te/g-C₃N₄/GS sensor was designed for the detection of DAPA. Furthermore, the effects of pH and scan rate on the electrochemical response were systematically evaluated using cyclic voltammetry (CV), while differential pulse voltammetry (DPV) was used for quantitative analysis. The sensor's electrochemical performance demonstrated high selectivity and sensitivity for DAPA detection. The linear range was 1-5 nM, and the limit of detection (LOD) and limit of quantification (LOQ) were 0.46 nM and 1.54 nM, respectively. Selectivity was evaluated in the presence of potential interferents, with minimal interference observed. The sensor exhibited excellent linearity with a correlation coefficient of 0.9989 and recovery values ranging from 94% to 110%. Furthermore, the method was successfully employed to determine DAPA in pharmaceutical samples and real water samples from the Yamuna River (Wazirabad barrage). Overall, the results validate that the proposed sensor exhibits reliable and effective performance for real-sample analysis.