Liu Zhengwen, Liu Shaopu, Wang Lei, Peng Juanjuan, He Youqiu
Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, BeiBei District, Chongqing 400715, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Sep 15;74(1):36-41. doi: 10.1016/j.saa.2009.04.026. Epub 2009 May 13.
In pH 6.6 Britton-Robinson buffer medium, the CdS quantum dots capped by thioglycolic acid could react with aminoglycoside (AGs) antibiotics such as neomycin sulfate (NEO) and streptomycin sulfate (STP) to form the large aggregates by virtue of electrostatic attraction and the hydrophobic force, which resulted in a great enhancement of resonance Rayleigh scattering (RRS) and resonance non-linear scattering such as second-order scattering (SOS) and frequency doubling scattering (FDS). The maximum scattering peak was located at 310 nm for RRS, 568 nm for SOS and 390 nm for FDS, respectively. The enhancements of scattering intensity (DeltaI) were directly proportional to the concentration of AGs in a certain ranges. A new method for the determination of trace NEO and STP using CdS quantum dots probe was developed. The detection limits (3 sigma) were 1.7 ng mL(-1) (NEO) and 4.4 ng mL(-1) (STP) by RRS method, were 5.2 ng mL(-1) (NEO) and 20.9 ng mL(-1) (STP) by SOS method and were 4.4 ng mL(-1) (NEO) and 25.7 ng mL(-1) (STP) by FDS method, respectively. The sensitivity of RRS method was the highest. The optimum conditions and influence factors were investigated. In addition, the reaction mechanism was discussed.
在pH 6.6的Britton-Robinson缓冲介质中，巯基乙酸包覆的硫化镉量子点能与氨基糖苷类（AGs）抗生素如新霉素硫酸盐（NEO）和硫酸链霉素（STP）发生反应，借助静电引力和疏水力形成大的聚集体，导致共振瑞利散射（RRS）以及共振非线性散射如二次散射（SOS）和倍频散射（FDS）显著增强。RRS的最大散射峰分别位于310 nm处，SOS的最大散射峰位于568 nm处，FDS的最大散射峰位于390 nm处。在一定范围内，散射强度的增强量（ΔI）与AGs的浓度成正比。建立了一种利用硫化镉量子点探针测定痕量NEO和STP的新方法。采用RRS法的检测限（3σ）分别为1.7 ng mL⁻¹（NEO）和4.4 ng mL⁻¹（STP），采用SOS法的检测限分别为5.2 ng mL⁻¹（NEO）和20.9 ng mL⁻¹（STP），采用FDS法的检测限分别为4.4 ng mL⁻¹（NEO）和25.7 ng mL⁻¹（STP）。RRS法的灵敏度最高。研究了最佳条件和影响因素。此外，还探讨了反应机理。
