Synthesis of crystalline silver nanoplates and their application for detection of nitrite in foods

The high-yield crystalline silver nanoplates were synthesized by mixing para-phenylenediamine (PPD) and silver nitrate with the addition of an appropriate amount of formic acid at low temperature. X-ray diffraction measurements show that the silver samples are pure face-centered cubic (fcc) phase with a preferred orientation of (111) direction. The silver nanoplates modified electrode (AgNP/GC) exhibits an excellent electrocatalytic activity toward the oxidation of nitrite (NO2-). The corresponding linear range and detection limit are estimated to be from 1 x 10(-5) M to 1 x 10(-3) M (r = 0.999) and 1.2 x 10(-6) M, respectively, at a signal-to-noise ratio of 3. It was successfully applied to the determination of nitrite in some food samples and the results were consistent with those obtained with the standard spectrometer procedure. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.