Preparation, characterization and stability of “8 17”DNAzyme substrate gold nanoparticle conjugates

Abstract:

“8-17” DNAzyme substrate gold nanoparticles conjugates (17S AuNPs) were prepared by ligand exchanged reaction. It was characterized using dynamic light scattering (DLS) and UV Vis absorption spectrum. The results indicated that the well dispersed gold nanoparticles showed a surface plasma peak at 520 nm in the UV Vis absorption spectrum, whereas the peak of 17S AuNPs conjugates red shifted to wavelength 523 nm. Meanwhile, the hydrodynamic radius of AuNPs and 17S AuNPs were confirmed to be 21.8 nm and 38.6 nm, respectively, using DLS. Moreover, the stability toward salt induced aggregation of AuNPs and 17S AuNPs was further investigated, respectively. As the concentrations of Na+ increased gradually, the absorptiom peak of AuNPs increased at 600 nm, following with a color change from red to blue. For 17S AuNPs a peak at 600 nm is not observed, and the color of the 17S AuNPs solution keeps red. The aforementioned results indicated that 17S AuNPs showed a higher stability than that of AuNPs.