A highly sensitive coupling technique for the determination of trace quercetin based on solid substrate room temperature phosphorimetry and poly (vinyl alcohol) complex imprinting

Al3+ could react with quercetin (Q) to form [AlQ](3+) complex which could be used as a template for the preparation of poly (vinyl alcohol)-[AlQ](3+) complex imprinting (PVA-C-I). The [AlQ](3+) not only had good matching ability and selectivity with the cavity of PVA-C-I, but also could react with the fluorescein isothiocyanate anion (FITC-) on the outside of cavity by electrostatic interaction to form ion-association complex [AlQ](3+)center dot[(FITC)(-)](3). The ion-association complex could emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM) and the Delta I-p of the system had linear relationship with the content of Q showing the highly selective identification of PVA-C-I to Q. Thus, a new coupling technique for the determination of trace Q based on solid substrate room temperature phosphorimetry and poly (vinyl alcohol) complex imprinting (PVA-C-I-SSRTP) was established. The linear range and limit of detection (LOD) of this method were 0.010-2.0 (x 10(-12) g mL(-1)) and 2.0 x 10(-14) g mL(-1), respectively, showing wide linear range and high sensitivity of PVA-C-I-SSRTP. This method was used to determine the content of Q in waste water, and the results are consistent with those by spectrofluorimetry. Meanwhile. the mechanism for the determination of Q using PVA-C-I-SSRTP was also discussed. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.