日韩av大片在线观看欧美成人不卡|午夜先锋看片|中国女人18毛片水多|免费xx高潮喷水|国产大片美女av|丰满老熟妇好大bbbbbbbbbbb|人妻上司四区|japanese人妻少妇乱中文|少妇做爰喷水高潮受不了|美女人妻被颜射的视频,亚洲国产精品久久艾草一,俄罗斯6一一11萝裸体自慰,午夜三级理论在线观看无码

文獻(xiàn)名： Spectrofluorimetric determination of Hg2+ and Pb2+ using acetylcholinesterase (AChE)-based formation of silver nanoparticles

 

作者： D. Nanda Kumar,   Jaydeep Roy,   S. A. Alex,   N. Chandrasekaran and    A. Mukherjee

Centre for Nanobiotechnology, VIT University, Vellore – 632014, India

 

 

摘要：We herein report a novel fluorimetric detection method for Hg2+ and Pb2+ based on in situ formation of AgNPs, where thiocholine (TCh), a product obtained by the hydrolysis of acetylcholine (ACh) by acetylcholinesterase (AChE), can act as a stabilizing agent. Uniformly dispersed AgNPs were obtained in the control sample (in the presence of optimized concentrations of AChE, ATCh, AgNO3 and NaBH4) without addition of any inhibitors (Hg2+ or Pb2+), resulting in decreased fluorescence intensity. However, the addition of Hg2+ and Pb2+ to the reaction mixture tends to decrease the vibrational and rotational speed with an increase in the aggregate diameter of particles, and thus increases the emission intensity of AgNPs at 423 nm. The increase in the emission intensity can be well correlated to the increase in concentration of metal ions. The limit of detection (LOD) was found to be 1.47 × 10−14 M for Hg2+ and 0.324 × 10−10 M for Pb2+, and the proposed method was successfully used for the determination of Hg2+ and Pb2+ in environmental samples. Further, this sensor model was also employed to perform the concurrent detection of Hg2+ in the presence of Pb2+ or vice versa in aqueous solutions.