Gold nanoparticle-modified ultramicroelectrode arrays: A suitable transducer platform for the development of biosensors

Abstract

This work reports on the performance of gold ultramicroelectrode arrays (UMEAs) modified with gold nanoparticles (GNP) for the development of biosensors. As a proof of concept an amperometric peroxidase-based biosensor for the detection of phenolic compounds was developed. GNPs were electrodeposited on to the UMEA surface, thereby increasing its active area up to 100 times but without affecting its inherent electrodic properties. Horseradish peroxidase enzyme (HRP) was covalently immobilized over the electrodes by means of a thiol self-assembled monolayer (SAM). The resulting biosensors were applied to the amperometric detection of catechol. The use of GNP-modified UMEAs increased the sensitivity of the biosensor compared with the values achieved with bare UMEAs and microelectrode based biosensors.