Thiolated poly(aspartic acid)-functionalized two-dimensional MoS2, chitosan and bismuth film as a sensor platform for cadmium ion detection

Abstract

In this work, a sensitive electrochemical platform for determination of cadmium ions (Cd2+) is obtained using thiolated poly(aspartic acid) (TPA)-functionalized MoS2 as a sensor platform by differential pulse anodic stripping voltammetry (DPASV). The performance of the TPA-MoS2-modified sensor is systemically studied. It demonstrates that the TPA-MoS2 nanocomposite modified sensor exhibits superior analytical performance for Cd2+ over a linear range from 0.5 μg L-1 to 50 μg L-1, with a detection limit of 0.17 μg L-1. Chitosan is able to form a continuous coating film on the surface of the GC electrode. The good sensing performance of the TPA-MoS2-modified sensor may be attributed to the following factors: the large surface area of MoS2 (603 m2 g-1), and the abundant thiol groups of TPA. Thus, the TPA-MoS2-modified sensor proves to be a reliable and environmentally friendly tool for the effective monitoring of Cd2+ existing in aquacultural environments.