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

Al(3+) could react with quercetin (Q) to form AlQ complex which could be used as a template for the preparation of poly (vinyl alcohol)-AlQ complex imprinting (PVA-C-I). The AlQ 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·(FITC)(-). The ion-association complex could emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM) and the ΔI(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 (×10(-12) g mL(-1)) and 2.0×10(-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.