Enhanced electropolymerization of poly(xanthurenic acid)–MoS2 film for specific electrocatalytic detection of guanine and adenine

Abstract

Until now, research studies on the preparation of MoS₂-based polymer nanocomposites using the electropolymerization method have been scarce. Herein, for the first time, a poly(xanthurenic acid, Xa) film based on a thin-layer MoS₂ support was electrochemically prepared to form a highly electroactive biosensing platform. The thin-layer MoS₂ was obtained using a simple ultrasonic method from bulk MoS₂. The physical adsorption between MoS₂ and aromatic Xa improved the electropolymerization efficiency, accompanied by an increased electrochemical response of PXa. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) were utilized to characterize the morphology and investigate the electrochemical properties of the prepared interface. Compared with sole PXa or a MoS₂ modified electrode, the PXa–MoS₂ hybrid interface exhibited good electrocatalytic activity and prominent synergistic effect on guanine and adenine. A PXa–MoS₂ nanocomposite has the negative charge and a specific structure, which obviously prompts the adsorption of the positively charged guanine and adenine. Moreover, this nanocomposite is a promising candidate in electrochemical sensing and other electrocatalytic applications.