Electrochemical detection and photocatalytic performance of MoS2/TiO2 nanocomposite against pharmaceutical contaminant: Paracetamol

Abstract

Rapidly increasing sternness of the water crisis and environmental degradation are stimulating rapid development of photocatalysts and sensors. In this article, we report a non-metal plasmonic MoS2/TiO2 nanocomposite for electrochemical sensing and sunlight-driven photocatalysis of pharmaceutical contaminant; paracetamol (PCM). Nanocomposite and its constituent materials were synthesized by wet chemical approach and characterized using a range of analytical techniques. Before performing electrochemical sensing of PCM, an insight into electrochemistry of PCM was developed for which cyclic voltammetry (CV) was used. The square wave voltammetric technique was used for electrochemical sensing of PCM, using oxidation peak current of PCM as a signal. Sensing platform revealed a linear dynamic range from 0.5 μM to 750 μM with regression coefficient (r2) of 0.980 and is able to perform real sample analysis. Moreover, this electrochemical sensor shows excellent reproducibility of 0.554% relative standard deviation and well-defined peak separation from the peaks of interfering biological species like dopamine and ascorbic acid for selective analytical determination of PCM. Photocatalysis performance of synthesized composite was evaluated under visible light conditions. The synthesized nanocomposite showed enhanced photocatalytic activity against PCM, attaining a degradation rate of 40% in 25 mins. Photostability of the composite was assessed for three consecutive runs, and a comparative study was performed against basal material (TiO2). Unlike numerous other reports on photocatalytic studies, the cytotoxic activity of synthesized nanocomposite was evaluated against human skin keratinocytes (HaCaT) cells to ensure its applicability as environment-friendly photocatalyst. Keywords: MoS2/TiO2 nanocomposite, Electrochemical sensor, Photocatalysis, Pharmaceutical contaminant, Cytotoxicity