Silica-Modified Electrodes for Electrochemical Detection of Malachite Green

New silica-modified glassy carbon electrodes prepared with three different sorts of ordered mesoporous silica (OMS) were characterized and tested for the electrochemical detection of Malachite Green (MG). The electrodes were prepared by drop casting using silica suspensions and, for stability sake, a Nafion coating was deposited on the electrode top by the same technique. Square wave anodic stripping voltammetry was used to investigate the effect of various experimental parameters (deposition time, solution pH, silica type and concentration) on the performance of the modified electrodes. The best electrode (GC/MCM-41-NH2/Nafion) with detection limit 0.36μM, sensitivity 0.164±0.003A/M; linear domain 1-6μM was applied to detect MG in a commercial product commonly used as biocide in aquaria for ornamental fish.