Electrochemical Sensing Using Quantum-Sized Gold Nanoparticles

Abstract
This paper describes the electrocatalytic activity of quantum-sized thiolate protected Au25 nanoparticles and their use in electrochemical sensing. The Au25 film modified electrode exhibited excellent mediated electrocatalytic activity that was utilized for amperometric sensing of biologically relevant analytes, namely, ascorbic acid and uric acid. The electron transfer dynamics in the Au25 film was examined as a function of Au25 concentration, which manifested the dual role of Au25 as an electronic conductor as well as a redox mediator. The electron transfer study has further revealed the correlation between the electronic conductivity of the Au25 film and the sensing sensitivity.