Ag nanoparticles-decorated nitrogen-fluorine co-doped monolayer MoS2 nanosheet for highly sensitive electrochemical sensing of organophosphorus pesticides

Abstract

Two-dimensional (2D) MoS2 shows great potential in the areas of electrochemical sensors due to their ultrathin structure and predominant physicochemical properties. However, pristine 2D MoS2 nanostructure exists inherent disadvantages such as the limited electrical conductivity, surface area and easy aggregation or restacking. Here, nitrogen-fluorine co-doped monolayer 2D MoS2 nanosheet decorated with Ag nanoparticles (Ag NPs-N-F-MoS2) nanocomposite is prepared and it exhibits superior conductivity, remarkable electron mobility and high electroactive surface area. The obtained Ag NPs-N-F-MoS2 are employed as a sensing platform for the electrochemical determination of organophosphate pesticide, coupled with enzymatic inhibition. Under optimized conditions, the acetylcholinesterase (AChE)/amino functionalized carbon nanotubes (CNTs-NH2)/Ag NPs-N-F-MoS2 bioelectrode is superior in sensing performances for the detection of monocrotophos and chlorpyrifos, with wide linear ranges, low detection limit as low as 0.05 pg mL−1 (0.2 pM) and 1 pg mL−1 (3 pM) at a signal-to-noise ratio of 3, satisfactory selectivity, reproducibility and long-time storage stability. All results indicate that the Ag NPs-N-F-MoS2 nanocomposite holds great promise for constructing an ultra-sensitive electrochemical sensing interface for the determination of pesticides.