Wei Zhong



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Nanomaterial are widely used in different areas such as optical device, drug delivery, chemicals, mechanics, magnetics, catalysis, energy science, Nano therapeutics and space industries depend on the special physical properties. However, most methods to produce nanoparticles are expensive or environmental unfriendly which can involve in toxic chemical. Another reason is that the nanoparticles from bio-based protocols are hydrophilic which is compatible with biological materials. In this project, we chose Shewanella oneidensis which is Gram-negative bacterium as the organism to produce sliver nanoparticles from sliver nitrate solution. The mechanism of bacterial of ion metal ion reduction to stable metal nanoparticles is unclear, but the NADH-dependent reeducates, quinines, and soluble electron-shuttles are thought to play an important role in metal reduction. This research focused on the temperature and DMSO affects the synthesis of silver nanoparticles by Shewanella Oneidensis. At various temperatures, the bio-activity of bacterium is different which can affect the silver nanoparticles reducing rate and the spherical size and nanoparticle geometry. DMSO is an aprotic, polar solvent which can penetrate skin and other membranes without damaging the cells. Due to this property of DMSO, DMSO was utilized as a co-solvent, which may change biosynthesis of silver nanoparticles. The synthesis processes were carried out at different temperatures and DMSO concentration and the nanoparticle formation monitored by using UV-vis spectrometer scans of the aqueous layer of reaction at 0 hr, 24 hr and 48 hr.

Publication Date


Project Designation

Capstone Project

Primary Advisor

Donald A. Comfort

Primary Advisor's Department

Chemical and Materials Engineering


Stander Symposium project


Arts and Humanities | Business | Education | Engineering | Life Sciences | Medicine and Health Sciences | Physical Sciences and Mathematics | Social and Behavioral Sciences

DMSO and Temperature Contributions to Synthesis of Silver Nano-Particles by the Bacterium Shewanella oneidensis