Green principles can be applied to exploit greener nano-synthesis with the intention of producing risk-free nanoscale gold particles. Pear extract is used to obtain phytochemically-derived reducing agents for the generation and stabilization of gold nanoparticles under nontoxic conditions, reduce the complexity of current methodologies and enhance their efficiency.

Pear extract can be used for the synthesis of gold nanoparticles. Pear extract is a reservoir of hytochemicals such as organic acids, amino acids, peptides and proteins.besides saccharides. Saccharides in the extract provides synergistic reducing power for the rapid transformation of chloroaurate ions into gold nanoparticles. Fresh pears are used for the preparation of pear extract. Peeled yellow pear slices are ground in a blender, filtered through mesh and centrifuged twice to remove cell-free debris andis then filtered through a 0.2 μm filter and employed for the synthesis of gold nanoparticles. Doubledistilled water is used to dilute the aqueous chloroauric acid stock solution and the original pear extract during synthesis and to disperse the resulting gold nanoparticles.

Biosynthesis of gold nanoparticles (Pear-AuNPs) is done by adding pear extract at 50% (v/v) with a final concentration of HAuCl4 of 2 mM at 90deg C. The formation of nanoparticles is monitored by UV-vis spectroscopy. Appearance of a purple-red color indicats the formation of gold nanoparticles. This color is generated by the excitation of surface plasman vibrations in the nanoparticles. The mixture is centrifuged at 11,000 × g for 15 min at 4 deg C and the process of centrifugation and redispersion is repeated three times to remove unbound pear phytochemicals. Rapidly produced Pear-AuNPs within 20 min are collected and purified by repeated Centrifugation. The resulting nano-materials is safe biomedical applications. The competence of the pear extract to facilitate the functional reduction of gold ions under aqueous conditions satisfies the fundamental principles of green chemistry.

Earlier reports indicate that the synthesis of gold nanoparticles using geranium extract required more time to initiate and it is completed in 48 h, Biosynthesis of silver and gold nanoparticles using bacteria and fungi has been reported, and the time required for completion of the reaction ranged from 24 to 120 h. Intracellular synthesis, prolonged synthesis, multiple purification steps and the maintenance of cell cultures are the drawbacks of microbial procedures. Coffee, tea and soybeans, Cinnamomum camphora leaf extract, Emblica officinalis fruit extract have been identified as effcient reducing and stabilizing agents for the production of gold as well as silver nanoparticles.