Electrochemical detection of food preservative SO2 in red wine using SiO2 coated CdS nanomaterials

Abstract

Cadmium sulfide is an important chalcogenide semiconductor nanoparticle prepared by reverse micelle method using cetyltrimethylammonium bromide (CTAB), surfactant. Toxic CdS is coated with silica using tetraethyl orthosilicate (TEOS) precursor and are well characterized. SiO2 provides a sufficient contrast to show the core homogeneously surrounded by the silica shell. The coating can be made thicker by the addition of TEOS resulting in monodispersed silica spheres with CdS core. SO2 is the most important chemical (as preservative and antioxidant) used to prevent wine oxidation. CdS@SiO2 is serving as adsorbent for the detection of SO2 in wine. The detection mechanism and the sensitivity of the method were validated using limit of detection and the limit of quantification values which are determined from differential pulse voltammetric technique. This electrochemical sensing is found to be simple and reliable to detect the free SO2 present in the wine sample.