State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8565, Ibaraki, Japan.
Mikrochim Acta. 2020 Mar 4;187(4):200. doi: 10.1007/s00604-020-4159-1.
In present study, we discovered unusual solvent-mediated aggregation-enhanced emission (AEE) character of 11-mercaptoundecanoic acid capped gold nanoclusters (MUA-Au NCs). When aggregated in aqueous media, the MUA-Au NCs showed strong emission, which was weakened by adding ethanol. Interestingly, the suppressed emission was selectively enhanced in the presence of hydrogen sulfide (HS) because HS was absorbed onto Au NCs through the strong sulfur-gold bonding affinity. The hydrolyzed HS, namely, HS, made the Au NCs negatively charged, which aggregated again due to decreased solubility. The HS-mediated fluorescence enhancement can be further amplified by introducing a hydrophilic thiolate (glutathione, GSH) onto the surface of Au NCs (GSH/MUA-Au NCs), which enabled sensitive determination of HS. Under the optimized condition, a detection limit of 35 nM was achieved. The determination was not interfered by other anions such as F, Cl, Br, I, OAc, N, NO, HCO, SCN, SO, and SO. This excellent sensing performance allowed practical application of the GSH/MUA-Au NC-based sensing platform to accurate determination of HS in human serum samples. Graphical abstractUnusual aggregation-enhanced emission character of 11-mercaptoundecanoic acid capped gold nanoclusters is discovered and has been applied for fluorometric hydrogen sulfide detection.
在本研究中，我们发现了 11-巯基十一酸（MUA）包裹的金纳米簇（Au NCs）异常的溶剂介导聚集增强发射（AEE）特性。当在水相介质中聚集时，MUA-Au NCs 表现出强烈的发射，而加入乙醇后发射强度减弱。有趣的是，由于 HS 通过与 Au NCs 之间的强硫-金键合亲和力被吸附到 Au NCs 上，所以在存在硫化氢（HS）的情况下，抑制的发射被选择性增强。HS 的水解产物，即硫氢根（HS），使 Au NCs 带负电荷，由于溶解度降低而再次聚集。由于在 Au NCs 表面引入了亲水性硫醇（谷胱甘肽，GSH）（GSH/MUA-Au NCs），HS 介导的荧光增强可以进一步放大，从而实现了对 HS 的灵敏检测。在优化条件下，检测限达到 35 nM。该测定不受其他阴离子如 F、Cl、Br、I、OAc、N、NO、HCO、SCN、SO 和 SO 的干扰。这种优异的传感性能使得基于 GSH/MUA-Au NC 的传感平台能够实际应用于准确测定人血清样品中的 HS。
