Abstract：
Nerve agents have posed a huge threat to national and human security, and their sensitive detection is crucial. Herein, based on the oxidation of Ce4+ and the aggregation-induced emission (AIE) of glutathione-protected gold nanoclusters (GSH-Au NCs), a cascade reaction was designed to prepare oxidized 3,3\',5,5\'-tetramethylbenzidine (oxTMB) and GSH-Au NCs crosslinked by Ce3+ (Ce3+-GSH-Au NCs). oxTMB had a broad UV-visible absorption range (500-700 nm) and was capable of quenching the fluorescence of Ce3+-GSH-Au NCs at 590 nm through the internal filtration effect (IFE). Thiocholine (TCh), the hydrolysis product of acetylthiocholine chloride (ATCl) catalyzed by acetylcholinesterase (AChE), reduced oxTMB completely, resulting in a decrease in the absorption of oxTMB and the recovery of IFE-quenched fluorescence of Ce3+-GSH-Au NCs. Nerve agent sarin (GB) hindered the production of TCh and the reduction of oxTMB by inhibiting the AChE activity, leading to the fluorescence of Ce3+-GSH-Au NCs being quenched again. The dual-output sensing system (AChE + ATCl + oxTMB + Ce3+-GSH-Au NCs) exhibited a low limit of detection to GB (2.46 nM for colorimetry and 1.18 nM for fluorimetry) and excellent selectivity toward common interferences being unable to inhibit AChE. Moreover, the intelligent logic gate constructed based on the sensing system showed promising applications in the field of smart sensing of nerve agents.
摘要：
神经毒剂对国家和人类安全构成了巨大威胁，它们的灵敏检测至关重要。在这里，基于Ce4的氧化和谷胱甘肽保护的金纳米簇（GSH-AuNC）的聚集诱导发射（AIE），设计了一个级联反应来制备氧化的3,3'，5,5'-四甲基联苯胺（oxTMB）和由Ce3（Ce3-GSH-AuNC）交联的GSH-AuNC。oxTMB具有宽的紫外可见吸收范围（500-700nm），并且能够通过内部过滤效应（IFE）猝灭590nm处的Ce3-GSH-AuNC的荧光。硫胆碱(TCh),乙酰胆碱酯酶(AChE)催化乙酰硫代胆碱氯化物(ATCl)的水解产物,完全减少了oxTMB，导致oxTMB的吸收减少，并恢复了Ce3-GSH-AuNCs的IFE猝灭荧光。神经毒剂沙林（GB）通过抑制AChE活性阻碍了TCh的产生和oxTMB的减少，导致Ce3+-GSH-AuNCs的荧光再次猝灭。双输出传感系统（AChEATCloxTMBCe3-GSH-AuNC）对GB的检测限很低（比色法为2.46nM，荧光法为1.18nM），并且对常见干扰具有出色的选择性，无法抑制AChE。此外，基于该传感系统构建的智能逻辑门在神经毒剂智能传感领域显示出广阔的应用前景。
