الفهرس 
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Abstract
The development of rapid and reliable processes for the synthesis of nanosized materials is of great importance in the field of nanotechnology. Synthesis of silver nanoparticles (AgNPs) using microorganisms has been reported, but the process is rather slow. The aim of the current study is to develop rapid and simple green biosynthesis method of AgNPs using bacterial supernatant (B. supernatant).Combinatorial biosynthesis using bacterial supernatant with either light irradiation or thermal effect was described. Photochemical biosynthesis has been assessed using coherent light sources: violet DPSS laser light (λ = 405 nm), green DPSS laser light (λ = 532 nm) and red He-Ne laser light (λ = 632.8 nm) and incoherent light sources: blue LED light (λ = 490 nm) and sun light. The nanoparticles prepared either by photochemical or by thermal biosynthesis were characterized via ultraviolet-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM). The results showed that only sun light and light sources in the blue region could be used for the photochemical biosynthesis of Ag-NPs with size ~ 10 nm. Moreover, thermal biosynthesis of B. supernatant either by conventional heating or microwave irradiation produced Ag-NPs with size ~ 6.5 nm. It was found that the AgNPs prepared either photochemically or thermally were highly monodipersed with spherical shape and stable for several months. For the first time, the synthesis of silver nanoparticles was achieved by broth media (culture broth media as well as by its ingredients) without bacterial inoculation using light irradiation or thermal effect. Finally, we can conclude that both photochemical and thermal biosynthesis of AgNPs are effective, simple, green, rapid and stable methods. Therefore, green biosynthesis of AgNPs could be used as a good alternative to the chemical methods when exposed to light photons or thermal energy.