双波长共振光散射比率法及其在槲皮素分析中的应用

Dual-Wavelength Resonance Light Scattering Ratiometry and Its Application in Quercetin Analysis

以槲皮素（QT）与Al^3＋的相互作用为例，建立了基于单次扫描光谱获得共振光散射信号升降变化的一种全新双波长比率法．Al^3＋在醋酸-醋酸钠缓冲溶液中形成的羟基配合物，随槲皮素加入，槲皮素将羟基配合物中的铝竞争下来形成槲皮素与铝的配合物，使得280nm处的散射强度（IRLS280）降低，444nm处的散射强度（IRLS444）增强．结果表明Log（IRLS^280／444nm）与槲皮素浓度在（2．5-25）×10^-5mol／L范围内呈线性关系，相关系数R=0．9980，检测限为2．0×10^-6mol／L．

Using the interaction of quercetin （QT） with Al^3＋ as an example, herein a dual-wavelength resonance light scattering （RLS） ratiometry was constructed for QT detection. In an acetate buffer solution, Al^3＋ formed a hydroxy complex, and with the addition of QT, Al^3＋ was contested from the hydroxy complex and preferential reaction between Al^3＋ and QT occurred, displaying notable changes of RLS signals. Consequently, the RLS intensity of Al^3＋ hydroxy complex at 280nm decreased, while the RLS intensity of Al^3＋-QT at 444 nm was enhanced remarkably. It was found that Log （IRLS 280/444 nm） linearly deereased with the QT concentration over the range of 2.5-25 × 10^-5 mol/L, with a detection limit of 2.5 × 10^-6 mol/L.