Ionic liquid–graphene hybrid nanosheets as an enhanced material for electrochemical determination of trinitrotoluene

Abstract

Trinitrotoluene, usually known as TNT, is a kind of chemical explosive with hazardous and toxic effects on the environment and human health. Ever-increasing needs for a secure society and green environment essentially require the detection of TNT with rapidity, high sensitivity and low cost. In this article, ionic liquid–graphene hybrid nanosheets (IL–GNs) have been used as an enhanced material for rapidly electrochemical detection of trinitrotoluene (TNT). IL–GNs were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photo-electron spectroscopy, electrochemical impedance spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and Raman spectroscopy, which confirmed that IL has been effectively functionalized on the surface of GNs. Significantly, IL–GNs modified glassy carbon electrode (GCE) showed 6.2 and 51.4-folds higher current signals for TNT reduction than IL–CNTs/GCE and bare GCE, respectively. Adsorptive stripping voltammetry (ASV) for the detection of TNT on IL–GNs exhibited a good linear range from 0.03 to 1.5 ppm with a detection limit of 4 ppb on the basis of the signal-to-noise characteristics (S/N = 3). Moreover, IL–GNs/GCE exhibited good stability and reproducibility for the detection of TNT. And, IL–GNs based electrochemical detection platform was also successfully demonstrated for the detection of TNT in ground water, tap water, and lake water with satisfactory results.