基于铜离子修饰金纳米簇“关-开”型荧光探针检测多巴胺

以11-巯基十一烷酸(11-MUA)为还原剂和保护剂,通过一步水热法合成了具有强烈荧光的水溶性金纳米簇(AuNCs),基于Cu~(2+)修饰的AuNCs@11-MUA构建了"关-开"型荧光探针用于多巴胺(DA)的选择性、高灵敏检测.向AuNCs@11-MUA溶液中加入Cu~(2+)离子后,AuNCs@11-MUA的荧光发生猝灭,体系的荧光信号处于"关闭"状态.在DA存在下,由于DA与Cu~(2+)具有更强的结合力,形成比Cu~(2+)/AuNCs@11-MUA复合体更稳定的络合物,可将Cu~(2+)从AuNCs@11-MUA表面移除下来,从而使其荧光得以恢复,体系的荧光信号呈"打开"状态.AuNCs@11-MUA探针的荧光恢复程度与DA的浓度在2.0×10~(-7)~5.0×10~(-5)mol/L范围呈良好的线性关系,检出限为8.0×10~(-8)mol/L(S/N=3).将该探针应用于人血清和尿液中DA的检测,回收率为93.2%~97.3%,相对标准偏差RSD4.08%,表明该方法可应用于人体内多巴胺的检测.

Cu2+Modified Gold Nanoclusters for Fluorescence Turn-on Detection of Dopamine

One-step hydrothermal method was used for the preparation of water-soluble gold nanoclusters (AuNCs) with strong fluorescence using 11-mercaptoundecanoic acid ( 11-MUA) as reducing agent and protective agent. A turn-on fluorescent probe based on Cu2+ modified AuNCs@ 11-MUA was developed for the detection of DA with high sensitivity and selectivity. After Cu2+ ions were added into AuNCs @ 11-MUA solution, the fluorescence of AuNCs@ 11-MUA was quenched, and the fluorescence signal of the system was in the "off" state. In the presence of DA, a more stable complex than the AuNCs@ 11-MUA-Cu2+ complex was formed due to DA and Cu2+ have a stronger binding force, which resulted in the departure of Cu2+ from the surface of the AuNCs@ 11-MUA, and the fluorescence signal of the system was " open". The fluorescence recovery degree of the AuNCs@ 11-MUA probe showed a good linear relationship with the concentration of DA from 2. 0×10-7 mol/ L to 5. 0×10-5 mol/ L. The limit of detection was estimated to be 8. 0×10-8 mol/ L(S / N=3). The present method was applied for the detection of DA in human serum and urine. Recoveries were found to be in the range of 93. 2%—97. 3%, and the result of statistical calculation shows that relative standard de-viations(RSDs) were lower than 4. 08%. The results indicate that present method can be applied for the detec-tion of DA in the human body.