Determination of Chromium(VI) in Textiles Based on Fluorescence Quenching of Nanogold Clusters

Chromium(VI) is one of the forbidden heavy metals in the ecological textiles. It is vitally important to develop methods for the sensitive and selective detection of CAD in textile samples. In this work, gold nano particles -sodium alginate clusters (AuNPs-SA) was prepared with sodium alginate in one-step synthesis route and its fluorescent property was investigated. The strongest fluorescence intensity of AuNPs-SA clusters located at the max emission wavelength lambda(em) =415 nm under the excitation wavelength of lambda(em) =360 nm. A fluorimetric method was developed based on the fluorescent AuNPs-SA nanocomposites selectively quenched in the presence of Cr(VI). The possible quenching mechanism was discussed on the basis of the interaction of positive AuNPs-SA with negative Cr (VI). Under the optimized experimental conditions, The ratiometric fluorescence was linearly proportional to the concentration of CAD ranging from 1.0x10(-8) moUL to 9.0x10(-8) moUL. The limit of determination (LOD) was estimated at 5.0 x10(-9) moUL based on the regression calculations. This method was used for the determination of chromium (VI) in textile samples, and the obtained result had no significant difference compare to the results based on the National Standard of the People's Republic of China (GB/T 17593.3-2006)