Research Article
Barry Morris and Farhad Beh
Abstract
The purpose of this investigation was to study the effects of gold (Au) and silver (Ag) nanoparticles on a commonly used enzymatic reaction between horseradish peroxidase (HRP) and the substrate, 3,3',5,5'-tetramethylbenzidine (TMB). Two different methodologies were used in this study. The first was the addition of small quantities of nanoparticles, directly onto a solution of streptavidin-peroxidase (streptavidin bound to HRP), prior to its reaction with TMB. The second was the addition of nanoparticles to immobilized streptavidin-peroxidase, covalently bounded to wells of a microtitre plate. In both cases, reactions with TMB were measured by visible absorbance spectroscopy, using a microtitre plate reader. The results indicate that both gold and silver nanoparticles have a significant effect; with gold suppressing the reaction and silver enhancing it.