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Abstract
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In the present study, we report on a simple, sensitive and selective chemosensor for the recognitionand monitoring of silver ions in aqueous solutions. It is based on the inhibitory effect of Ag(I) ion onthe chemiluminescence signal of H2O2–luminol system, which could be improved by at least 10-folds inthe presence of cobalt ferrite (CoFe2O4) magnetic nano-particles. The structure and morphology of thesynthesized CoFe2O4nano-particles were characterized by X-ray diffraction, Fourier transform infraredspectroscopy and scanning electron microscopy. The as-prepared CoFe2O4nano-particles were then usedas catalysts for H2O2–luminol chemiluminescence system. The enhanced chemiluminescence signal wasdramatically decreased by adding trace levels of Ag(I) ion into the solution. The possible mechanismto explain this finding was discussed. Several parameters affecting the analytical signal such as the pHvalue, the concentrations of H2O2, luminal and CoFe2O4nano-particles, incubation time and interferingions were investigated and optimized. Under the optimized experimental conditions, chemiluminescenceintensity of luminol–H2O2–CoFe2O4versus Ag(I) concentration gave a linear response within the rangeof 0.5–100 ng mL−1with a detection limit of 0.15 ng mL−1. The method was successfully applied to mon-itoring Ag(I) in various water samples.
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