A fluorescent method was developed for the quantitative analysis of iodine by synthesizing BSA-protected AuNCs(AuNCs@BSA) as fluorescent probe. Under the optimum conditions, the decrease of the fluorescent intensity of AuNCs@ BSA had a good linear relationship with iodine concentration in the range of 2.0 nmol/L-35 μmol/L, and the detection limit for iodine was 1. 8 nmol/ L. The proposed method was used to detect iodine in water, and the results were consistent with those obtained by ICP-MS method, which indicated that this method was a rapid and reliable technique for detection of iodine in real samples. The quenching mechanism of iodine with AuNCs@ BSA was studied by the modified Stern-Volmer equation and thermodynamic calculation, and CD and IR results revealed that the secondary-structure change of the capping ligand BSA played an important role in the fluorecent quenching of AuNCs@ BSA. In conclusion, the accurate and full data would make a significant contribution to understanding of the action mechanism and relationship between inorganic small molecules and protein protected metal nanoclusters.%以蛋白质保护的金纳米簇AuNCs@BSA作为荧光探针,高灵敏地检测碘含量.结果表明,碘单质可引起金纳米簇的荧光猝灭,在2.0nmol/L～35μmol/L浓度范围内具有良好的线性响应关系,检出限为1.8 nmol/L,利用建立的方法对水样中的碘单质进行定量测定,并与ICP-MS检测结果进行对比,结果证明该方法在实际样品的检测屮具有应用潜力,同时基于AuNCs@BSA与碘浓度的依赖效应,改变温度,诱导荧光响应变化,利用热力学计算,深入探讨了 AuNCs@BSA与碘单质之间的作用机理,圆二色谱与红外光谱的结果表明碘单质引起的配体BSA的蛋白二级结构变化,诱导了AuNCs@BSA的荧光猝灭.该文的机理研究为无机小分子与蛋白质保护的金纳米簇之间的相互作用提供了参考.
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