Novel electrochemical sensor for mononitrotoluenes using silver oxide quantum dots

Abstract

Mononitrotoluenes (MNTs) can cause methemoglobinemia, liver/kidney damage, and skin/eye/throat irritation. Monitoring of MNTs in real and laboratory samples is necessary to maintain levels below permissible limits. Herein, silver oxide quantum dots (Ag2O QDs) were synthesized using a chemical method and were well characterized using transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and UV-visible spectroscopy. The characterized QDs were coated on a gold (Au) electrode using a binder (Nafion). This modified electrode was evaluated and standardized for redox-based sensing against 2-nitrotoluene. Cyclic voltammetry (CV) was optimized for electrochemical determination of 2-nitrotoluene. The effects of various factors like scan rate, solution pH, analyte concentration, and possible interferants were also evaluated for sensing performance of 2-nitrotoluene. The fabricated sensor displayed a high sensitivity of 100 mu A cm(-2) ppm(-1) with a limit of detection of 4.3 ppm and a linear range of 5-40 ppm. The proposed technique was reliable for monitoring real as well as laboratory samples of 2-nitrotoluene.