CdTe量子点作探针共振瑞利散射法测定肝素钠

在水相中低温条件下制备了巯基乙胺稳定的CdTe量子点(CdTe QDs).基于肝素钠(Heparin)对巯基乙胺稳定的CdTe QDs共振瑞利散射(RRS)的增强作用,同时二级散射(SOS)和倍频散射(FDS)也相应增强,建立了一种快速、简便、定量测定肝素的新方法,同时讨论了最佳反应条件和影响因素,以RRS为例,在311 nm处,RRS的光谱强度与肝素钠的质量浓度c/(I-I_0)有良好的线性关系(r=0.999 1),线性范围13.5～1000 ng/mL,检出限(3σ)为4.04 ng/mL.可用于血样中肝素钠的测定.

Abstract：

Aqueous cysteamine-capped CdTe quantum dots(QDs) were prepared under low temperature.A simple and rapid quantitative method for heparin determination was proposed, based on the fact that hepa-tin can enhance CdTe QDs resonance Rayleigh scattering (RRS) and the intensities of second-order scatter-ing (SOS) and frequency-doubling scattering (FDS).Factors affecting RRS for detecting heparin with cys-teamine-capped CdTe QDs were studied.At 311 nm, the RRS calibration plot of C/(I-I_0) with concen-tration of heparin was linear in the range of 13.5-1 000 ng/mL with a correlation coefficient of 0.999.The limit of detection (30) was 4.04 ng/mL.     

硫化镉量子点-硫酸依替米星体系的共振瑞利散射和共振非线性散射光谱研究及其分析应用

在弱酸介质中,硫化镉量子点(CdS-QDs)与硫酸依替米星(ETM)在静电引力和疏水作用力下,形成粒径更大的聚集体,导致共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)显著增强,其最大散射峰分别位于310 nm(RRS),568 nm(SOS),320 nm(FDS).在一定范围内ETM浓度与三种散射增强程度(△I)成正比,可用于ETM的测定,其中RRS的灵敏度最高,其检出限(3σ)为1.6 ng/mL.考察了共存离子的影响,表明方法有良好的选择性.据此发展了以CdS-QDs作探针,高灵敏、简便测定ETM的共振瑞利散射新方法,用于人血清和尿样中ETM的测定,平均回收率在94.5%～113.7%之间.

Abstract：

In a medium of pH = 5.6, CdS quantum dots could react with etimicin sulfate to form larger aggregates by virtue of electrostatic attraction and the hydrophobic force, which resulted in a great enhancement in resonance Rayleigh scattering (RRS) and resonance non-linear scattering such as second-order scattering (SOS) and frequency doubling scattering (FDS). The maximum scattering peaks were located at 310 nm for RRS, 568 nm for SOS and 320 nm for FDS. The enhancements of scattering intensity (△I) were directly proportional to the concentration of etimicin sulfate (ETM) within a certain range. Of the three methods, RRS had the highest sensitivity, its detection limit (3σ) being 1.6 ng/mL. An examination of the effects of coexisting substances showed that the method had good selectivity. Based on these results, a new method, highly sensitive and simple, was developed, which can be used to determinate ETM by CdS-QDs as a probe. The recovery for the determination of ETM in human serum and uric samples was in the range of 94. 5%-113.7%.     

硒化锌量子点作探针荧光法检测农药敌磺钠

以谷胱甘肽(GSH)为稳定剂,在水相中合成了高荧光的硒化锌量子点(ZnSe QDs).实验发现,农药敌磺钠能显著猝灭ZnSe QDs的荧光,同时采用荧光光谱和吸收光谱研究了敌磺钠与ZnSe QDs相互作用的荧光猝灭机理.通过对比3个温度下体系的Stern-Volmer方程动态猝灭常数KSV发现,敌磺钠对ZnSe QDs的荧光猝灭主要为动态过程.利用二者的猝灭作用建立了对农药敌磺钠的高灵敏检测新方法,其线性范围为6.69×10-7～2.23×10-4 mol/L,相关系数为R=0.999,检出限为2.01×10-7 mol/L.用该方法对自来水中残留农药进行检测,加标回收率在95.8%～105%之间.     

CdTe量子点作探针共振瑞利散射法测定甲氨蝶呤、头孢曲松钠

以巯基乙胺为稳定剂,在水相中合成CdTe量子点,巯基乙胺自组装在量子点的表面形成带正电的聚合体,在pH为5.0～5.6的弱酸性条件下,带正电的CdTe量子点聚合体与带负电的甲氨蝶呤(Methotrexate MTX)、头孢曲松钠(Ceftriaxone CTRX)通过静电引力及疏水作用力结合形成粒径较大的聚合体,这种聚合体的形成导致共振瑞利散射(Resonance Rayleigh Scattering RRS)强度显著增大,同时二级散射(seconol-order scattering SOS)和倍频散射(frequency-doubling scattering FDS)也显著增强.在一定条件下,散射增强(△I)与甲氨蝶呤、头孢曲松钠的浓度成正比,其中RRS方法有较高的灵敏度,甲胺蝶呤和头孢曲松钠的线性范围分别为0.01～4.50 μg/mL,0.03～4.20 μg/mL,检出限(3σ)分别为3.06 ng/mL,8.90 ng/mL.这种方法灵敏、简便、快速,可用于血样中甲氨蝶呤、头孢曲松钠的痕量分析.