Electrochemical Luminescence Enhancement Of Luminol In Neutral System Synthesis And Characterization Of Ag@SiO₂, SiO₂@Ag Nanoparticle

Conductive glass (ITO) electrodes were modified with polyethylenimine (PEE) and polyacrylicacid (PAA) via electrostatic interaction, the electrochemical luminescence behavior of luminol on the modified electrodes was compared. It was found that the electrode process was scarcely affected by the PEE modification, but the electrochemical luminescence of luminol was greatly enhanced. This is attributed to the stabilization of the excited state of intermediate of luminol by the interaction with the positively charged PEE modified layer. The PAA modification influences the electrochemical reaction due to the electrostatic repulsion. ITO was modified with gold nanoparticles and formed two-dimensional submonolayer. The gold nanoparticles can catalyze the electrochemical reaction. The surrounding electronic field was enhanced by the lumiol electrochemical luminescence. The electrochemical luminescence of luminol was quenched because of the nonradiated energy transfer between the excitated luminol and gold nanoparticles. To avoid this, two method were used. First CTAB was used in the solution; second the NAu/ITO electrodes were modified with PEE and PAA. And then greatly enhancement of luminol electrochemical luminescence was obtained.Ag@SiO2 particles were synthesized by the hydrolyzing of TEOS in the presence of Ag nanoparticles. The thickness of SiO2 was controlled by the quantum of TEOS. There was red shift along with the thickness of SiO2. SiO2@Ag particles were synthesized by the silver nitrate deoxidizing. After several times growth, the surface of SiO2 was covered by Ag particles. The Absorption spectra of SiO2@Ag only...