Design of a new electrochemical sensing system based on MoS2–TiO2/reduced graphene oxide nanocomposite for the detection of paracetamol†
Herein, we designed a new electrochemical sensor (MoS2–TiO2/rGO/SPE) based on a molybdenum disulfide (MoS2)–titanium dioxide (TiO2)/reduced graphene oxide (rGO) nanocomposite-modified screen printed electrode (SPE) for the selective and sensitive detection of paracetamol (acetaminophen, Ac). This design was optimized by examining the effect of the rGO : MoS2–TiO2 ratio, MoS2–TiO2/rGO composite amount on the SPE, and pH of the electrolyte on the current signal of the fabricated sensor towards the oxidation of Ac. MoS2–TiO2/rGO/SPE showed linearity in the range of 0.1 μM to 125 μM with a high sensitivity of 0.4425 μA μM−1. The detection limit (LOD) was found to be 0.046 μM. To test the applicability of MoS2–TiO2/rGO/SPE for practical analysis, a few drops of drug and human urine samples were directly applied on the surface of the fabricated sensor for measuring Ac after dilution of the samples with 0.1 M phosphate buffer solution (pH 7.4). Furthermore, the specificity of MoS2–TiO2/rGO/SPE was evaluated by monitoring the current changes in the presence of possible interferents in biological fluids.