Sensitive and direct electrochemical detection of bisphenol S based on 1T&2H-MoS2/CNTs-NH2 nanocomposites

Abstract

As an alternative to bisphenol A (BPA), bisphenol S (BPS) is widely used in many consumer goods and industrial products. However, BPS has similar genotoxic, reproductive and endocrine disrupting effects to BPA and can enter the body through the food chain or by dermal absorption to endanger human health. This paper presents a rapid and direct electrochemical sensing technique for ultra-trace BPS determination on the basis of the signal amplification of the 1T phase & 2H phase hybrid MoS₂ nanosheets (1T&2H-MoS₂) and amino-functionalized carbon nanotube (CNTs-NH₂) composites. The cooperative electrocatalytic effect and high-electrically active surface area of 1T&2H-MoS₂/CNTs-NH₂ composites not only facilitated the electron transfer between BPS and the electrode, but also promoted the adsorption of BPS on the electrode. Hence, the 1T&2H-MoS₂/CNTs-NH₂ modified electrode exhibited excellent electrocatalytic activity with a lower oxidation potential and higher peak current for BPS. Under the optimized conditions, the peak current response of BPS showed a good dose-dependent relationship with its concentration in the range of 0.02–1.0 μM and 1.0–70.0 μM, while the detection limit was as low as 8.6 nM. The proposed method was used to determine BPS in the mineral water bottle and orange juice samples with satisfactory spiked recoveries between 92.31% and 104.20%, demonstrating its reliability and practicality in real sample analysis. Furthermore, the sensing method has the characteristics of facile electrode fabrication, fast response (<4 min) and good reproducibility.