Journals Proceedings

Abstract

A facile, rapid and green synthesis of gold and silver nanoparticles (GNPs and SNPs) using juice of different fruits as reducing and stabilizing agent is reported. Seven different fruits were used in the comparative study with green tea and coffee: lemon, melon, pineapple, banana, orange and tomato. The efficiency of the fruits for the synthesis and stabilization of metallic nanoparticles was compared at pH 3, 7 and 10. The effect of the buffer agent, phosphate and HEPES, was also studied. The early analysis of NP formation was done by observing the color change of the samples. Alkaline pH was favorable for the synthesis of metallic NPs at all the tested conditions. Green tea and coffee were the most efficient agents for the synthesis of GNPs and SNPs. The formation of the GNPs was evident only few seconds after the addition of gold salt solution in the extracts. The most efficient fruits for GNP synthesis were lemon, banana and orange. In the presence of these fruits the formation of GNPs was evident few minutes after the addition of gold salt. HEPES buffer accelerated significantly the rate of GNP formation by fruits. In the presence of HEPES GNP formation using fruits was evident immediately after the addition of gold salt. The fruit-mediated SNP synthesis was relatively slow, spent hours or days according to the fruit type and were not accelerated by HEPES. The GNPs synthetized using fruits were characterized by UV–Vis spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and zeta potential. The GNPs were predominantly spherical and presented different zeta potential values indicating that biomolecules composing fruit juices such as sugars and flavonoids remained capping the NPs.