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Analytical Applications of Enzymatic Growth of Quantum Dots
Author(s) -
Saa Laura,
Virel Ana,
SanchezLopez Jose,
Pavlov Valery
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200903373
Subject(s) - chemistry , quantum dot , sodium thiosulfate , cadmium sulfide , alkaline phosphatase , thiosulfate , substrate (aquarium) , thiophosphate , enzyme , esterase , nuclear chemistry , inorganic chemistry , biochemistry , nanotechnology , organic chemistry , materials science , sulfur , oceanography , geology
We have developed an analytical assay to detect the enzymatic activity of acetylcholine esterase and alkaline phosphatase based on the generation of quantum dots by enzymatic products. Acetylcholine esterase converts acetylthiocholine into thiocholine. The latter enhances the rate of decomposition of sodium thiosulfate into H 2 S, which in the presence of cadmium sulfate yields CdS quantum dots showing a time dependent exponential growth, typical of autocatalytic processes. This assay was also applied to detect acetylcholine esterase inhibitors. Alkaline phosphatase hydrolyzes thiophosphate and yields H 2 S, which instantly reacts with Cd 2+ to give CdS quantum dots. The formation of CdS quantum dots in both reactions was followed by fluorescence spectroscopy and showed dependence on the concentration of enzyme and substrate.