Microwave Assisted Rapid and Green Synthesis of Silver Nanoparticles Using a Pigment Produced by Streptomyces coelicolor klmp33

Traditional synthesis of silver nanoparticles using chemical methods produces toxic substances. In contrast biological synthesis is regarded as a safe and nontoxic process but the major drawback of biological synthesis is, this process is slow. In the present investigation, we developed a rapid and green synthesis of silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33 in just 90？s. The silver nanoparticles were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biobased synthesis developed in this method is a safe, rapid, and appropriate way for bulky synthesis of silver nanoparticles. 1. Introduction Nanotechnology is expected to be the basis of many important technological innovations in the 21st century [1]. Various physical and chemical methods were reported for the synthesis of silver nanoparticles, but most of these methods cause potential environmental and biological hazards [2]. Compared to physical and chemical methods, biological synthesis using microbes and plants was regarded as a safe and ecofriendly process [3]. Several biological synthesis methods, using microbes like Cladosporium cladosporioides [4] and Fusarium oxysporum [5], have been suggested as safe, cost-effective, possible ecofriendly ways and alternatives to chemical and physical methods, but these methods also have the drawback that these processes were rather slow [6]. Parallel to microbes mediated synthesis, several rapid plant mediated synthesis method using crude plant parts extracts like Sorbus aucuparia [7] and Chenopodium album [8] were also reported, but large scale usage of plants for industrial purpose synthesis may lead to loss of valuable species [9]. Therefore, there is a need to develop a rapid and ecofriendly process for the synthesis of silver nanoparticles. In our earlier study, we reported synthesis of silver nanoparticles using pigment produced by Streptomyces coelicolor klmp33 by photoirradiation method in 20？min, but still we think the synthesis is more time consuming [10]. So, we explored different methods using the same pigment produced by S. coelicolor klmp33 to overcome this problem. Among different methods, microwave assisted synthesis showed promising result; the advantage of microwave irradiation over conventional biological synthesis is the improvement in rate kinetics of the reaction due to rapid heating and penetration involved, which may result in a narrow distribution of the particle size [11, 12].