Electrochemical Detection of 2,4,6-Trinitrotoluene on L-Cysteine-Modified Porous Silicon Electrode in Dimethyl Sulfoxide Solution

In this work, the electrochemical process of 2,4,6- trinitrotoluene (TNT) reduction on a new type of electrode based on a L-Cysteine-modified porous silicon (PSi) in organic electrolyte was studied. The functionalized by silanization process with APTES was used to prepare the PSi electrode. Cyclic voltammograms of modified-PSi electrode in DMSO/ TBAFB solution containing TNT exhibited two major reduction peaks in the potential rang (-0.7 V-+ 0.4 V / Ag/AgCl), the third reduction peak at -0.64 V presents a very weak current intensity. The presence of these peaks corresponds to the multistep process of TNT reduction. The electrochemical response of TNT reduction was a quasi-reversible process. The TNT concentration was shown to vary in a linear manner with the current intensity with a detection limit of 0.2 nM. The change in the solution color from colorless to red or deep red was attributed to TNT-amine complexes.