Electrochemical chloramphenicol sensors-based on trace MoS2 modified carbon nanomaterials: Insight into carbon supports

Abstract Carbon nanomaterials are considered as potentially promising sensing materials for fabrication of high-performance electrochemical chloramphenicol (CAP) sensors. However, it is highly required to investigate the structure effect of carbon supports on electrochemical sensing performances. Herein, three typical carbon nanomaterials were selected as carbon supports to deposition of trace MoS2, including reduced graphene oxide (rGO), multi-walled carbon nanotubes (MWCNTs) and carbon black (CB), which were subsequently used to construct electrochemical CAP sensors. The combined characterizations of Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy indicate that these MoS2 modified carbon nanomaterials show the morphology and microstructures similar with carbon supports as used. Electrochemical tests indicate that the sensing performances of these CAP sensors are dependent on the structure of carbon supports. Among all these MoS2 modified carbon nanomaterials, MoS2 modified rGO hybrids display large electrochemically active surface area and low interfacial resistance between electrolyte and electrode, resulting in the highest sensitivity of 3.581 μA·μM-1·cm-2. As a result, rGO is regarded as good candidate for fabrication of high-performance CAP sensors, compared to MWCNTs and CB. The present work not only clarifies structure effect of carbon supports on electrochemical sensing performances, but also provides help for the construction of high-performance electrochemical sensors and biosensors based on carbon nanomaterials.