An aptamer-based biosensor for the detection of lysozyme with gold nanoparticles amplification

Herein, we present a simple signal-off electrochemical lysozyme aptasensor with gold nanoparticles modification. Gold nanoparticles were anchored onto a gold electrode surface which was previously modified with self-assembled monolayers of p-aminothiophenol. In this work, p-aminothiophenol, gold nanoparticles amplification, and the DNA duplex in which one strand was covalently attached with thiol and the other was tagged with Fc, were three main protocols employed in lysozyme detection. The SWV peak current decreased with increasing concentration of lysozyme. A lower detection limit of 0.1 pM lysozyme has been obtained. The aptasensor also presents high specificity for lysozyme, which is not affected by the coexistence of other proteins. Such an aptasensor opens a rapid, selective and sensitive route for lysozyme detection and provides a promising strategy for other protein detections. (C) 2010 Elsevier B.V. All rights reserved.