DSAZn与槲皮素的配位结合及对槲皮素的高灵敏度检测

Coordination Interaction of DSAZn With Quercetin and High Sensitivity Detection of Quercetin

槲皮素为天然黄酮类化合物,可用于高血压、高血脂、心血管疾病、癌症等的预防和治疗;槲皮素的定量检测在生物化学、临床医学等领域尤为重要。利用分子荧光物质(DSAZn)的聚集诱导发光现象(AIE),通过配位作用识别靶标分子槲皮素,结合激发态电子转移原理,提出了一种AIE型荧光分子对槲皮素的高灵敏度、高选择性检测方法。实验研究了pH 7.0的PBS缓冲液中DSAZn的荧光随着五种药物分子(槲皮素、淫羊藿素、异鼠李素、芦丁、多巴胺)加入后的变化情况。采用荧光分光光度计,以415 nm为激发波长,扫描435~680 nm的荧光发射光谱。采用紫外分光光度计,扫描DSAZn 250~750 nm的紫外吸收光谱。紫外检测表明中药分子槲皮素可以与AIE荧光探针形成复合物,因此加入槲皮素后AIE探针的荧光被静态猝灭。荧光检测表明五种药物分子对荧光探针的猝灭强弱有明显差异,槲皮素与DSAZn结合常数为1.34×10^(7) L·mol^(-1),比其他四种药物分子和DSAZn的结合常数高出一个数量级,显示出DSAZn对槲皮素具有较好的选择性。槲皮素的检测限为3.07 nmol·L^(-1),低于诸多文献已报道的参考值,表明DSAZn对槲皮素的识别具有较高的灵敏度。由荧光滴定光谱和荧光滴定曲线得到槲皮素对DSAZn的滴定方程为:y=0.0134x-0.29482,槲皮素浓度在0~5μmol·L^(-1)范围内线性关系良好,线性相关系数r=0.9943。由此构建出一种AIE型荧光分子对槲皮素的高选择性、高灵敏度检测方法,该方法操作简便、重复性好,为具有相似结构药物的检测提供了新的研究思路。

Quercetin is a natural flavonoid compound that is used for the prevention and treatment of hypertension,hyperlipidemia,cardiovascular disease,cancer,etc.Therefore,quantitative detection of quercetin was particularly important in biochemistry and clinical medicine.A highly selective and sensitive detection methodfor quercetin with AIE(aggregation-induced luminescence phenomenon)fluorescent molecules was proposed,which identified the target molecule quercetin through coordination interaction with excited state electron transfer.The fluorescence of DSAZn in PBS buffer at pH 7.0 with adding five drug molecules(quercetin,icaritin,isorhamnetin,rutin and dopamine)was studied.The fluorescence emission spectra of 435~680 nm were scanned by a fluorescence spectrophotometer with an excitation wavelength of 415 nm.The ultraviolet absorption spectrum of 250~750 nm was scanned by ultraviolet spectrophotometer,which showed that the traditional Chinese medicine molecule quercetin could form a complex with the AIE fluorescent probe and thusstaticallyquenchedthe fluorescence of the AIE probe.Fluorescence detection showed that the quenching effect of five drug molecules on the fluorescent probe was significantly different.The binding constant of quercetin and DSAZn was 1.34×10^(7) L·mol^(-1),which was an order of magnitude higher than that of the other four drug molecules,exhibitinga good selectivity for quercetin.The detection limit of quercetin was 3.07 nmol·L^(-1),which was lower than the value reported in many kinds of literature,exhibiting a high sensitivity for quercetin.The titrationcurve equation of quercetin to DSAZn based on the fluorescence titration spectrum was:y=0.0134x-0.29482.The linear range of quercetin concentration was 0~5μmol·L^(-1) with a linear correlation coefficient of 0.9943.Thus,a highly selective and sensitivedetection method for quercetin by AIE-type fluorescent molecules was constructed.This method was simply operated and repeatable,which provided a new research idea for detecting drugs with similar structures.