Wang Jiahui, Zhang Hao, Guan Ruifang
School of Material Science and Engineering, University of Jinan, Jinan 250000, China.
Materials (Basel). 2018 Nov 9;11(11):2232. doi: 10.3390/ma11112232.
Dual-emission nanosensor for Hg detection was prepared by coupling CA-AEAPMS on the surface of RBS-doped modified silica microspheres. The CA-AEAPMS was synthesized by using -(β-aminoethyl)-γ-aminopropyl methyldimethoxysilane (AEAPMS) and citric acid as the main raw material. The obtained nanosensor showed characteristic fluorescence emissions of Rhodamine B (red) and CA-AEAPMS (blue) under a single excitation wavelength (360 nm). Upon binding to Hg, only the fluorescence of CA-AEAPMS was quenched, resulting in the ratiometric fluorescence response of the dual-emission silica microspheres. This ratiometric nanosensor exhibited good selectivity to Hg over other metal ions, because of the amide groups on the surface of CA-AEAPMS serving as the Hg recognition sites. The ratio of F/F linearly decreased with the increasing of Hg concentration in the range of 0 to 3 × 10 M, and a detection limit was as low as 97 nM was achieved. Then, the addition of three thiol-containing amino acids (Cys, Hcy, GSH) to the quenched fluorescence solution with Hg can restore the fluorescence, and the detection limits of the three biothiols (Cys, Hcy, GSH) are 0.133 μM, 0.086 μM, and 0.123 μM, respectively.
通过将CA - AEAPMS偶联在罗丹明B掺杂的改性二氧化硅微球表面制备了用于汞检测的双发射纳米传感器。以-(β-氨乙基)-γ-氨丙基甲基二甲氧基硅烷(AEAPMS)和柠檬酸为主要原料合成了CA - AEAPMS。所制备的纳米传感器在单一激发波长(360 nm)下呈现罗丹明B(红色)和CA - AEAPMS(蓝色)的特征荧光发射。与汞结合后，只有CA - AEAPMS的荧光被猝灭，导致双发射二氧化硅微球的比率荧光响应。由于CA - AEAPMS表面的酰胺基团作为汞识别位点，这种比率纳米传感器对汞的选择性优于其他金属离子。在0至3×10 M范围内，F/F的比率随汞浓度的增加呈线性下降，检测限低至97 nM。然后，向含有汞的猝灭荧光溶液中加入三种含硫醇氨基酸(Cys、Hcy、GSH)可以恢复荧光，三种生物硫醇(Cys、Hcy、GSH)的检测限分别为0.133 μM、0.086 μM和0.123 μM。
