| Abstract
| - An electrochemical sensor for ultratrace nitroaromaticcompounds (NACs) using mesoporous SiO2 of MCM-41as sensitive materials is reported. MCM-41 was synthesized and characterized by scanning electron microscope,transmission electron microscopy, and small-angle X-raydiffraction. Glassy carbon electrodes modified with MCM-41 show high sensitivity for cathodic voltammetric detection of NACs (including 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene, and 1,3-dinitrobenzene) down to the nanomolar level. The highsensitivity is attributed to the strong adsorption of NACsby MCM-41 and large surface area of the working electrode resulting from MCM-41 modification. The voltammetric response is fast, and the detection of NACs can befinished within 14 s. SiO2 nanospheres were similarlyused to modify glassy carbon electrodes for electrochemical detection of TNT and TNB. The detection limit of SiO2nanosphere-modified electrodes is lower than that ofMCM-41-modified electrodes, possibly due to the smallersurface area of SiO2 nanospheres than mesoporous MCM-41. The results show mesoporous SiO2-modified glassycarbon electrodes, particularly MCM-41-modified electrodes, open new opportunities for fast, simple, andsensitive field analysis of NACs.
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