Electrochemical assay for As (III) by combination of highly thiol-rich trithiocyanuric acid and conductive reduced graphene oxide nanocomposites

We propose an electrochemical assay for As(III) based on trithiocyanuric acid deposited reduced graphene oxide (TTCA/rGO) using square wave anodic stripping voltammetry (SWASV). In this work, TTCA/rGO is prepared by a simple one-pot method using NaBH4 as the reducing agent. Many TTCA molecules are successfully deposited on the surface of rGO through π-π conjugation, which endows the TTCA/rGO with excellent adsorption ability of As(III) via As−S bond. Combining the outstanding conductivity of rGO, the response of electrochemical current for As(III) determination is greatly amplified in the electrochemical detection process. Under optimum conditions, the TTCA/rGO modified gold electrode shows high sensitivity and good selectivity for the detection of As(III) with a low detection limit down to 0.054 ppb, which is promising to be applied for the rapid and sensitive determination of As(III) in complicated samples.