Synthesis Of Nanomaterials By DNA And Microorganism Templates And Application

With the fast development of science and technology, the synthesis research and character detection of new-style nano-materials had achieved significant improvement. Current nano-synthesis methods include physical and chemical techniques, but they are characterized by elevated temperatures, long growth times, high pressures, low yields, and also environmentally hazardous. However, there is an interesting and exciting biogenic synthesis to prepare various nanomaterials, This method is very simple, reliable, clean, nontoxic and environmentally friendly procedure.Deoxyribonucleic acid (DNA) is an attractive bio-molecule as a template of nanostructures because of its narrow width (ca.2nm) and ability to self-recognize and self-assembly DNA has been widely exploited as a template for the fabrication of a variety of nanomaterials. The cells of microorganism have many kinds of geometrical shapes and can be used for a template of nanomaterials. Bacillus subtilis and E. Coli are readily available and easy to handle without much difficulty. Synthesis of nanomaterials by DNA and bacteria template, characters of these materials and applications of sensor were been important discussed. The main results are summarized as follows:1. A very simple and novel approach of fabricating Ag-DNA network is reported. The Ag-DNA network can be formed from reduction of cationic silver absorbed on DNA template by sunlight. Mesh size of the Ag-DNA network and diameter of the Ag-DNA nanowire can be controlled by adjusting the concentration of DNA and irradiation time, respectively. Furthermore, the Ag-DNA network placed onto comb-like gold electrodes can be utilized as a biosensor, which presents a good response for the detection of caricnoembryonic antigen (CEA).2. We reported a very simple, reliable, clean, nontoxic and eco-friendly biological method for the synthesis of semiconductor monoclinic Se nanoparticles by the Bacillus subtilis. The as-synthesized Se nanoparticles were spherical shapes with diameters of ranging from 50 to 400 nm. These spherical monoclinic spherical Se nanoparticles can be transformed into highly anisotropic, one-dimensional (1D) trigonal structure after one day at the room temperature and grown from aqueous solutions. Furthermore, the obtained two kinds of perfect appearance Se nanomaterials crystals with high surface-to-volume ratio, good adhesive ability and biocompatibility have been employed as enhancing and settled materials for H2O2 biosensor.3. Ag nanoparticles were synthesized by E.Coli. The various culture factors affecting the synthesis of Ag nanoparticles were discussed. The samples were characterized by SEM, XRD and UV-Vis. We tried to explore a green new approach of the synthesis of nanomaterials.