Inhibitive determination of mercury ion using a renewable urea biosensor based on self-assembled gold nanoparticles

.A renewable potentiometric urease inhibition biosensor based on self-assembled gold nanoparticles has been developed for the determination of mercury ions. Gold nanoparticles were chemically adsorbed on the PVC-NH2 matrix membrane pH electrode surface containing N,N-didecylaminomethylbenzene (DAMAB) as a neutral carrier and urease was then immobilized on the gold nanoparticles. The response characteristics of the DAMAB/PVC-NH2 pH-sensitive membrane and the effects of the size of nanoparticles have been investigated in detail. The linear range of determination of Hg2+ was 0.09-1.99 mu mol L-1 with a detection limit of 0.05 mu mol L-1. The advantages of self-assembled immobilization are low detection limit, fast response and ease regeneration. The assembled gold nanoparticles and inactive enzyme layers denatured by Hg2+ can be rinsed out via a saline solution with acid and alkali successively. This sensor is generally of great significance for inhibitor determination, especially in comparison with expensive base transducers. (c) 2005 Elsevier B.V. All rights reserved.