Selective fluorescence sensor based on ion-imprinted polymer-modified quantum dots for trace detection of Cr(VI) in aqueous solution.

Selective fluorescence sensor based on ion-imprinted polymer-modified quantum dots for trace detection of Cr(VI) in aqueous solution.
Anal Bioanal Chem. 2019 Sep 05;:
Authors: Zhang MY, Huang RF, Ma XG, Guo LH, Wang Y, Fan YM
Abstract
A new fluorescence sensor (QDs-IIP), based on ion-imprinted polymers (IIP) as recognition element and Mn-doped ZnS quantum dots (QDs) as fluorophore, was synthesized for the selective and sensitive determination of hexavalent chromium (Cr(VI)) ions. The QD was first coated by SiO2 layer, and then modified with Cr(VI)-imprinted polymer. Several parameters affecting fluorescence intensity such as tetraethylorthosilicate (TEOS) volume, ZnS:Mn@SiO2 amount, and radiation time were investigated and optimized. The QDs-IIP was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), transmission electron microscope (TEM), and scanning electron microscope (SEM). Furthermore, the fluorescence quenching mechanism was investigated by using UV-VIS and fluorescence spectrophotometer, and it was found that internal filtration effect was the main fluorescence quenching mechanism. The relative fluorescence intensity (F0/F) increased linearly with the increase of Cr(VI) concentration in the range of 20 μg L-1-1.0 mg L-1. The QDs-IIP sensor showed high recognition selectivity for Cr(VI) in comparison with the QDs-NIP sensor with an imprinting factor (IF) of 2.53, and it could be reused 5 times. In...

Source: Analytical and Bioanalytical Chemistry - September 4, 2019 Category: Chemistry Authors: Zhang MY, Huang RF, Ma XG, Guo LH, Wang Y, Fan YM Tags: Anal Bioanal Chem Source Type: research