The synergistic effects of MoS2 and reduced graphene oxide on sensing performances for electrochemical chloramphenicol sensor

The electrochemical sensors for chloramphenicol (CAP) detection have been explored and applied in the field of food safety because of the striking merits of fast detection speed, high sensitivity and easy operation. The effective electrocatalysts possessing excellent catalytic activity for electrochemical reduction of CAP are highly desirable for determination of CAP. Herein, we developed high-performance electrochemical CAP sensor based on MoS2 modified reduced graphene oxide (MoS2-rGO) hybrids, prepared by one-pot hydrothermal synthesis method. The successful deposition of MoS2 onto rGO nanosheets was confirmed by several characterizations, including X-ray diffraction, Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. Most importantly, the sensing performances of electrochemical CAP sensor based on MoS2-rGO hybrids are better than the sensors based on MoS2 as well as rGO, including sensitivity of 4.566 μA·μM−1·cm−2, linear range of 1–55 μM and limit of detection of 0.6 μM. The excellent sensing performances of MoS2-rGO hybrids-based CAP sensor are derived from the synergistic effects of MoS2 and rGO. As expected, rGO serves as conductive linker between electrolyte and electrode increasing electrons transfer rate. Meanwile, the deposition of MoS2 onto rGO leads to the formation of three-dimensional conductive networks further enhanced the surface active sites and electron transferring rate. For example, the MoS2-rGO-3 hybrids display large electrochemical surface area of 0.146 cm2, and low interfacial resistance of 6.2 Ω. The present protocol could be spread on synthesis of functional materials for constructing high-performance electrochemical sensors.