Interaction of polyphenols and Ag on the surface plasmon resonance absorption and resonance Rayleigh scattering spectra

Polyphenols are a kind of vital biologically active substances in fruits and vegetables. In this study, with the reductive ability in the alkaline solution, eight polyphenols[(-)-Epigallocatechin gallate (EGCG), (-)-Epigallocatechin (EGC), (-)-Epicatechin gallate (ECG), (-)-Epicatechin (EC), (-)-Gallocatechin gallate (GCG), (-)-Gallocatechin (GC), (+)-Catechin (C) and Gallic acid (GA)] could produce silver nanoparticles(AgNPs) with [Ag(NH 3 ) 2 ] + . It was found that the AgNPs had intense surface plasmon resonance bands at 415 nm and RRS spectra signals at 450 nm, which were linearly related to the concentration of polyphenols. It was used for the spectrophotometric and RRS spectra determination of the former eight polyphenols with low detection limits. The developed method was applied for the determination of polyphenols in tea and products.