A new strategy for silver deposition on Au nanoparticles with the use of peroxidase-mimicking DNAzyme monitored by Localized Surface Plasmon Resonance technique
in: Sensors (2017)
Peroxidase-mimicking DNAzyme was applied as a catalyst of silver deposition on gold nanoparticles. This DNAzyme is formed when hemin binds to the G-quadruplex-forming DNA sequence. Such a system is capable to catalyze redox reaction with one or two electrons transfer. The process of silver deposition was monitored by localized surface plasmon resonance technique, which allows recording scattering spectrum of a single nanoparticle. Our study showed that DNAzyme is able to catalyze silver deposition. The AFM experiments proved that DNAzyme induced deposition of silver shell of approximately 20 nm thickness on Au nanoparticles. Such effect is not observed when hemin is absent in the system. However, we noticed that addition of hemin alone, led to the nonspecific binding of this molecule on the gold surface that also enhanced silver deposition. Analysis of SEM images indicated that the surface characteristics of silver layer deposited by DNAzyme are different than that for hemin alone. Proposed strategy of silver layer synthesis on gold nanoparticles catalyzed by DNAzyme is an innovative approach and can find application in bioanalysis (LSPR, electrochemistry) as well as in material sciences.