Determination of Explosives Using Electrochemically Reduced Graphene

Abstract

A graphene‐based electrochemical sensing platform for sensitive determination of explosive nitroaromatic compounds (NACs) was constructed by means of electrochemical reduction of graphene oxide (GO) on a glassy carbon electrode (GCE). The electrochemically reduced graphene (ER‐GO) adhered strongly onto the GCE surface with a wrinkled morphology that showed a large active surface area. 2,4‐Dinitrotoluene (2,4‐DNT), as a model analyte, was detected by using stripping voltammetry, which gave a low detection limit of 42 nmol L⁻¹ (signal‐to‐noise ratio=3) and a wide linear range from 5.49×10⁻⁷ to 1.1×10⁻⁵ M. Further characterizations by electrochemistry, IR, and Raman spectra confirmed that the greatly improved electrochemical reduction signal of DNT on the ER‐GO‐modified GC electrode could be ascribed to the excellent electrocatalytic activity and high surface‐area‐to‐volume ratio of graphene, and the strong π–π stacking interactions between 2,4‐DNT and the graphene surface. Other explosive nitroaromatic compounds including 1,3‐dinitrobenzene (1,3‐DNB), 2,4,6‐trinitrotoluene (TNT), and 1,3,5‐trinitrobenzene (TNB) could also be detected on the ER‐GO‐modified GC electrode at the nM level. Experimental results showed that electrochemical reduction of GO on the GC electrode was a fast, simple, and controllable method for the construction of a graphene‐modified electrode for sensing NACs and other sensing applications.