茜素红“开关式”荧光探针测定水中微量铜

Determination of trace copper in water by alizarin red“switch”fluorescent probe

当pH=5.2时茜素红与过量的Al^(3+)反应生成发射橙黄色荧光的络合物,该络合物的最佳激发和发射波长分别为469 nm和585 nm,Cu^(2+)能够使茜素红-铝体系荧光猝灭,且荧光猝灭程度与Cu^(2+)的浓度在一定范围内呈线性关系,据此建立了一种灵敏的“开关式”测定Cu^(2+)的方法.探究了茜素红-铝-铜体系的最佳用量比、反应温度、反应时间、pH、缓冲溶液等因素对反应体系的影响.结果表明:测定Cu^(2+)的工作曲线为ΔF=19.7c+101.2,R^(2)=0.9995,线性为0.2~30μmol/L,检出限0.022μmol/L.该方法准确度高,灵敏度高,选择性好,可用于水中微量铜的检测.

A complex emitting orange yellow fluorescence were generated by the mixture of the alizarin red and excessive Al^(3+) at pH=5.2.The maximum fluorescence excitation and emission wavelength of the colored complex were located at 469 nm and at 585 nm,respectively,The fluorescence intensity of the alizarin red-Al^(3+) system could be quenched by a certain amount of Cu^(2+),and the fluorescence quenching value showed a linear relationship with the concentration of Cu^(2+) within limits,thus establishing a sensitive and switching method for the determination of Cu^(2+).The optimal factors of the determination system were investigated,such as the dosage ratio,reaction temperature,reaction time,pH and buffer solution.The results showed that the standard working curve wasΔF=19.7c+101.21(R^(2)=0.9995),the linear range was 0.2~30μmol/L,and the detection limit was 0.022μmol/L.The method shows high accuracy,high sensitivity,good selectivity,and could be used for the detection of trace copper ion in water.