Determination of explosives using electrochemically reduced graphene

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.