Electrochemical sensing using quantum-sized gold nanoparticles

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.