Enhanced chemiluminescence of the luminol-AgNO3 system by Ag nanoparticles

The oxidation reaction of luminol with AgNO3 can produce chemiluminescence (CL) in the presence of silver nanoparticles (NPs) in alkaline solution. Based on the studies of UV-vis absorption spectra, photoluminescence (PL) spectra and CL spectra, a CL enhancement mechanism is proposed. The CL emission spectrum of the luminolAgNO3Ag NPs system indicated that the luminophore was still 3-aminophthalate. On injection of silver nanoparticles into the mixture of luminol and AgNO3, they catalysed the reduction of AgNO3 by luminol. The product luminol radicals reacted with the dissolved oxygen, to produce a strong CL emission. As a result, the CL intensity was substantially increased. Moreover, the influences of 18 amino acids, e.g. cystine, tyrosine and asparagine, and 25 organic compounds, including gallic acid, tannic acid and hydroquinone, on the luminolAgNO3Ag NPs CL system were studied by a flow-injection procedure, which led to an effective method for detecting these compounds. Copyright (c) 2011 John Wiley & Sons, Ltd.