Surface Plasmon Spectral Shifts of Functionalized Gold Nanoparticles for the Use in Biosensors

摘要

Recently there has been a great interest in the use of gold nanoparticles to detect the hybridization process of DNA. The method uses the physical phenomenon that describes size-dependent Surface Plasmon Resonance (SPR) of gold nanoparticles and its shift to greater wavelengths upon their aggregation. Here we report on the synthesis of gold nanoparticles coated with functional linker biomolecules and their spectral shift driven by the formation of the avidin-biotin complex towards the use of these materials in the development of DNA biosensors. The gold nanoparticles were covalently functionalized by biotin and BSA-biotin in aqueous solution. UV-vis analysis of the dispersed colloidal nanoparticles resulted in a characteristic absorption spectra. Upon the addition of the avidin, the aggregation of gold nanoparticles was inferred from the alteration of absorption spectra.