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.