Silver nanoparticle-initiated chemiluminescence reaction of luminol-AgNO3 and its analytical application

Ag+ has been regarded as an inert chemiluminescent oxidant. In this work, it was found that in the presence of silver nanoparticles (AgNPs), AgNO3 could react with luminol to produce strong chemiluminescence (CL). The AgNPs with smaller size could initiate stronger CL emission. To investigate the CL mechanism of the AgNPs-luminol-AgNO3 system, the UV-visible spectra and the CL spectrum of the CL system were obtained. The CL reaction mechanism involving catalysis was proposed. Compared with the reported nanoparticles-luminol-H2O2 CL system, the AgNPs-luminol-AgNO3 CL system has the advantages of low background and good stability. Moreover, the new CL system was used in immunoassay for IgG.