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Amperometric Sensing Based on Glutathione Protected Au 25 Nanoparticles and Their pH Dependent Electrocatalytic Activity
Author(s) -
Kumar S. Senthil,
Kwak Kyuju,
Lee Dongil
Publication year - 2011
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201100240
Subject(s) - nanoclusters , ascorbic acid , chemistry , electrochemistry , amperometry , electrode , selectivity , electrocatalyst , inorganic chemistry , glutathione , electrochemical gas sensor , nanoparticle , catalysis , nanotechnology , materials science , organic chemistry , enzyme , food science
We report here the electrochemical behavior of quantum sized glutathione protected Au 25 nanoclusters and their use in electrochemical sensing. The Au 25 modified electrode was found to show excellent electrocatalytic activity towards the oxidation of ascorbic acid and dopamine over a wide linear range from 0.71 to 44.4 µM. The modified electrode exhibited pH dependent electrocatalytic activity, which was attributed to the consequence of electrostatic attraction/repulsion between the charged Au 25 clusters and the charged analytes at different pH. This result demonstrates the feasibility of enhancing the sensing selectivity among the charged analytes by controlling the charges on the clusters.