Preparation Of Au Hollow Nanoshells And Their Localized Surface Plasma Resonance For Sensing

Noble metal nanoparticles exhibit rich localized surface plasmon resonanceproperties, which is highly dependent on the composition, shape and size of metalnanoparticles and the surrounding refractive index. So we can prepare LSPR sensorswhich is cheap, versatile, as well as sensitive.In this paper, we develop a simple galvanic replacement reaction method betweenAg nanoparticles and HAuCl₄to prepare the Au hollow nanoshells on ITO surface.Firstly, Ag nanoparticles were deposited on ITO surface by cyclic voltammetry. Weprepare a variety of sizes and shapes of Ag nanoparticles by controlling depositionpotential. Then Au hollow nanoshells were prepared by a template sacrifice method.The Au hollow nanoshells on ITO substrate were characterized by means of UV-visspectroscopy, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, X-rayspectroscopy （EDS） and X-ray diffraction （XRD）. The influences of the reaction containthe temperature, time and the concentration of HAuCl₄solution were investigated. TheLSPR peak wavelength of the nanoparticles could be regulated and controled in therange of480nm1000nm.On the other hand, the Au hollow nanoshells decorated on ITO substrate wereused to investigate the response of different organic solvents. The sensitivitis of Auhollow nanoshells at an average diameter of50and100nm were160and280nm/RIU,which was about more than doubled higher than that of original Ag nanoparticles. Thenthe analytical performances of sensor chips for monitoring both thiol and proteinadsorption were examined. We chose the biotin-streptavidin and h-IgG/goatanti-I-h-IgG systems to validate the LSPR properties.