碲化镉量子点自组装膜的构建及其对溶菌酶的界面传感

Fabrication of CdTe Quantum Dots Self-assembled Multilayers and Interfacial Sensing for Lysozyme

利用自组装膜(SAMs)技术在石英片表面构建了碲化镉量子点SAMs。考察了组装液浓度、组装时间和聚电解质组装层数等组装条件对膜发光性能的影响,并用紫外可见吸收光谱仪、荧光光谱仪、共聚焦荧光显微镜和原子力显微镜对其进行了表征。基于溶菌酶对该SAMs的荧光具有猝灭效应,建立了一种快速灵敏测定痕量溶菌酶的界面荧光分析法,线性响应范围为0.10～10.19μg/L,检出限为48 ng/L,灵敏度较纯液相分析提高3个数量级。所构建的SAMs具有良好的稳定性和可逆再生性,在0.1 mol/L NaCl溶液(pH 12.0)中浸泡1 h即可实现再生。本方法用于人血清中溶菌酶的测定,回收率为85.7%～105.5%。

CdTe quantum dots（QDs） were synthesized directly in aqueous solution by using thioglycolic acid as the stabilizer.And CdTe QDs self-assembled monolayers（SAMs） were fabricated onto the quartz surface.The assembly conditions such as polyelectrolyte concentration,assembly time and polyelectrolyte assembled layers were investigated,and the SAMs were characterized via UV-vis absorption spectra,fluorescence spectra,confocal fluorescence microscope and atomic force microscopy.A fast and sensitive method was established to detect trace lysozyme based on the fluorescence quenching of CdTe SAMs by lysozyme.In addition,a good linear relationship between fluorescence response and concentration of lysozyme could be obtained in the range from 0.10 μg/L to 10.19 μg/L,the detection limit was 48 ng/L,and the sensitivity was higher than the pure liquid method by 3 orders of magnitude.The CdTe SAMs sensor is stable and can be regenerated by immersing into 0.1 mol/L NaCl solution of pH 12.0 for 1 h.The proposed method was successfully applied to lysozyme detection in human serum samples with recovery of 85.7%-105.5%.