Hybrid Nanostructure Composed of Homogeneously Decorated MoS2 Nanosheets on Graphene for Simultaneous Electrochemical Determination of Amlodipine and Hydrochlorothiazide

Abstract

A single-stage hydrothermal approach was performed for the synthesis of molybdenum disulfide nanosheets/graphene (MoS2 NSs-G) hybrid nanostructures, in which the surface of graphene is tightly and homogeneously decorated with MoS2 nanosheets. XRD, TEM, FE-SEM, and EDX analysis were performed to confirm the structural characteristics of MoS2 NSs-G. The MoS2 NSs-G hybrid modified screen-printed carbon electrode (MoS2 NSs-G/SPCE) was fabricated by drop-casting the hybrid suspension on the surface of an SPCE. The assessment of the electrochemical behavior of amlodipine at the surface of MoS2 NSs-G/SPCE was carried out by cyclic voltammetry (CV) and differential pulse voltammetric analysis (DPV). The modified electrode exhibited superior electrocatalytic activity for the oxidation of amlodipine compared to the bare SPCE. The structure of MoS2 NSs with plenty of edge sites and synergistic effects between MoS2 NSs and graphene can promote electrochemical performances. The MoS2 NSs-G/SPCE provides satisfactory results, reaching a limit of detection (LOD) of 0.0012 μM for the determination of amlodipine within a linear range of 0.04–400.0 μM. Moreover, the sensor shows favorable results for the concurrent measurement of amlodipine and hydrochlorothiazide. The key advantages of the fabricated sensor include stability and enhanced sensitivity, which will be favorable for amlodipine and hydrochlorothiazide clinical assay.