L-半胱氨酸包覆的ZnS:Mn^(2+)水溶性的量子点荧光探针测定氟尿嘧啶的含量

Detection of fluorouracil using L-cysteine capped ZnS:Mn^(2+) quantum dots as fluorescence probe

目的:以绿色环保材料为基础,在温和的条件下合成了水溶性的L-半胱氨酸包覆的锰离子掺杂的硫化锌量子点(L-Cys/ZnS:Mn2+QDs),并以此为荧光探针建立了测定抗癌药物氟尿嘧啶(FU)的新方法。方法:研究了FU对L-Cys/ZnS:Mn2+QDs荧光的淬灭作用并阐述了可能的作用机理。实验还考察了缓冲液体系、pH、反应时间、量子点浓度等多种因素对测定FU的影响。结果:在磷酸盐(pH6.5)缓冲溶液中,L-Cys/ZnS:Mn2+QDs浓度为1.6×10-4mol.L-1时,FU在1.0~85μg.mL-1的浓度范围内对量子点的荧光强度有较强的猝灭作用,且体系的荧光强度变化与溶液中氟尿嘧啶的浓度符合斯特恩方程,线性方程为:Y=0.01059C+0.9757(r=0.9988);猝灭常数为1.377×103L.mol-1;检出限为0.38μg.mL-1。将方法应用于实际样品FU注射液的分析,获得满意结果,FU的加样回收率为99.2%~100.0%。结论:该法简便、快速、灵敏度高,可望将其作为一种新型的荧光标记物用于体内药物的示踪和测定。

Objective：Mn2＋ doped ZnS semiconductor quantum dots（QDs） have been synthesized using L-cysteine as surface modifying agent through a facile process in an aqueous solution.The QDs was then used to detect the fluorouracil（FU） as a fluorescence probe.Method：The effect of FU on the fluorescence intensity of L-Cys/ ZnS：Mn2＋ QDs has been investigated.The reaction mechanisms were also been put forward.Some experiment conditions were studied such as the butter solution systems,the pH value and the concentration of QDs.Results：Under optimum conditions,the fluorescence intensity of QDs against the concentration of fluorouracil was linear over the concentration range of 1.0-85 μg·mL-1 with an excellent 0.9988 correlation coefficient.The quenching constant could be obtained,which was 1.377×103L·mol-1 and the detection limit was 0.38 μg·mL-1.The method has been applied to the determination of the fluorouracil injection with satisfactory results.The recoveries of spiked components of FU were 99.2%-100.0%.Conclusions：The method presented here is simple,rapid,sensitive and suitable for practical application.