Beijing National Laboratory for Molecular Sciences; Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China.
College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, P.R. China.
Analyst. 2020 Mar 16;145(6):2233-2237. doi: 10.1039/c9an02495f.
The discriminative monitoring of biothiols in biological fluids is a great challenge. Herein, we developed a fluorescence "turn-off-on" probe based on AuNCs-AuNPs ensembles, which detected l-cysteine (l-Cys) with high selectivity. The strong blue fluorescence of l-hydroxyproline-capped gold nanoclusters (l-Hyp@AuNCs) at 465 nm was quenched by AuNPs via the inner filter effect. Interestingly, the fluorescence was recovered by interaction with l-Cys due to the electrostatic and specific Au-S interactions between l-Cys and AuNPs. The effect of the l-Cys amount on the fluorescence "off-on" efficiency showed good linearity in the range of 1.5-35.0 μM (R2 = 0.986) with a detection limit of 1.4 μM (3σ). The proposed method was successfully applied to test the serum l-Cys levels without the interference of glutathione, homocysteine and methionine. The AuNCs-AuNPs ensembles-based fluorescence "turn-off-on" protocol shows great potential in specific biothiol sensing.
生物流体中生物硫醇的区分监测是一项巨大的挑战。在此，我们开发了一种基于金纳米簇-金纳米颗粒组装体的荧光“关闭-开启”探针，该探针对 l-半胱氨酸（l-Cys）具有高选择性。l-羟脯氨酸封端的金纳米簇（l-Hyp@AuNCs）在 465nm 处具有强的蓝色荧光，通过内滤效应被金纳米颗粒猝灭。有趣的是，由于 l-Cys 与金纳米颗粒之间的静电和特定的 Au-S 相互作用，与 l-Cys 相互作用后荧光恢复。l-Cys 量对荧光“关闭-开启”效率的影响在 1.5-35.0 μM 范围内表现出良好的线性关系（R2 = 0.986），检测限为 1.4 μM（3σ）。该方法成功应用于测试血清 l-Cys 水平，而不受谷胱甘肽、同型半胱氨酸和蛋氨酸的干扰。基于金纳米簇-金纳米颗粒组装体的荧光“关闭-开启”方案在特定生物硫醇传感中具有很大的潜力。
