L-半胱氨酸包覆ZnS纳米荧光探针测定诺氟沙星的研究___

摘要 目的：建立以L-半胱氨酸包覆ZnS纳米粒子为荧光探针测定药物制剂中诺氟沙星含量的荧光分析法。方法：研究了L-半胱氨酸包覆ZnS纳米粒子对诺氟沙星荧光强度的影响，发现在KH2PO4-NaOH缓冲溶液中, 诺氟沙星与L-半胱氨酸包覆ZnS纳米粒子相互作用使体系的荧光强度增强。测定时最佳pH为6.5, L-半胱氨酸包覆ZnS纳米粒子的最佳浓度为4.0×10-4 mol•L-1。结果：诺氟沙星浓度在 4.0×10-9～1.2×10-6 mol•L-1范围内与体系的荧光强度线性关系良好，相关系数r = 0.9985，检出限(S/N = 3)为7.4×10-10 mol•L-1，定量限(S/N = 10)为4.0×10-9 mol•L-1。对浓度为1.6×10-7 mol•L-1诺氟沙星标准溶液平行测定9次的RSD为1.8%。结论：该法简便、快速,灵敏度高，可用于直接测定诺氟沙星含量。

Abstract Objective: A sensitive fluorimetric method for determining norflxacin in Pharmaceutical samples with L-cysteine-capped ZnS nanoparticles as fluorescence probe was established. Methods: The effect of L-cysteine-capped ZnS nanoparticles on the fluorescence intensity of norflxacin has been investigated. It was found that the fluorescence intensity of the system was greatly enhanced duo to the interactions of norflxacin and L-cysteine-capped ZnS nanoparticles in the KH2PO4-NaOH buffer solution. The optimal pH was 6.5and the optimal concentration of L-cysteine-capped ZnS nanoparticles was 4.0×10-4 mol•L-1. Results: Under optimum conditions, the fluorescence intensity of the system showed a good linear relationship with the concentration of norflxacin in the range of 4.0×10-9 to 1.2×10-6 mol•L-1, the correlation coefficient was 0.9985, the detection limit (S/N = 3) was 7.4×10-10 mol•L-1 and the limit of quantification (S/N = 10) was 4.0×10-9 mol•L-1 . The RSD was 1.8% for the determination of 1.6×10-7 mol•L-1 norflxacin (n = 9). Conclusion: This method was simple, rapid, accurate, and may be used directly for the determination of norflxacin.

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