硫化锌掺锰量子点磷光探针法快速检测牛奶中的三聚氰胺

摘要

基于三聚氰胺(MA)对谷胱甘肽(还原型)包覆的硫化锌掺锰量子点磷光的猝灭作用，建立了快速测定牛奶中 MA 的磷光探针法。实验结果表明，在中性溶液中，MA 浓度在8.0~70.0 nmol/L 范围内，磷光量子点强度的猝灭值(ΔPL)与 MA 的浓度呈线性关系，线性方程为ΔPL=1.59cMA+15.17，相关系数(r)为0.9965，方法检出限4.0 nmol/L。将本方法用于牛奶加标样品中 MA 的分析，RSD 为3.26%，MA 的平均回收率为90.05%～98.08%。%A new phosphorescent sensor method for determination of melamine in milk was developed based on phosphorescent quenching of glutathione-coated Mn-doped ZnS quantum dots (Mn:ZnS QDs) by MA. Experimental results show that a good linear relationship between the phosphorescent intensity quenched(ΔPL) and the concentration of MA can be obtained at the range of 8.0~70.0 nmol/L in the aqueous media with a detection limit 4.0 nmol/L. The calibration equation is ΔPL= 1.59cMA + 15.17 with a correlation coefficient(r) 0.9965. The method has been used to determine MA in spiked samples of milk with 3.26% RSD, and the spiked recovery is in the range of 90.05%~98.08%.