Amperometric sensing of NADH at gold nanorods stabilized in amine-functionalized silicate sol–gel matrix modified electrode

Abstract

The gold nanorods stabilized in amine-functionalized silicate sol–gel matrix (Au–TPDT NRs) in aqueous medium are prepared and their application toward the electrochemical sensing of reduced β-nicotinamide adenine dinucleotide (NADH) is demonstrated. The prepared Au–TPDT NRs is characterized by using absorption spectroscopy and transmission electron microscopy. The electrochemical characteristics of the Au–TPDT NRs modified electrode are studied by using cyclic voltammetry. The electrocatalysis and electrochemical sensing of NADH at physiological pH using the Au–TPDT NRs modified electrode are investigated. The amperometric sensing of NADH shows enhanced electrocatalytic activity for the Au–TPDT NRs modified electrode without incorporating any mediator due to the synergetic catalytic effect of Au NRs and TPDT silicate sol–gel matrix. The amperometric current increased linearly with increasing the NADH concentration in the range from 1 to 13 µM and the lowest detection limit is estimated as 0.38 µM. The present work demonstrates that the GC/Au–TPDT NRs modified electrode is simple to prepare and shows good response for the electrochemical detection of NADH.