Extracellular biosynthesis and transformation of selenium nanoparticles and application in H2O2 biosensor

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 shaped with diameters ranging from 50 to 400 nm. These spherical monoclinic 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 Se nanomaterial crystals with high surface-to-volume ratio, good adhesive ability and biocompatibility have been employed as enhancing and settled materials for H2O2 biosensor. The results show that the H2O2 biosensor has high sensitivity and affinity for H2O2. The detection limit for H2O2 was found to be 8 x 10(-8) M. Different crystals of Se nanomaterials have no significant difference in electrochemical application. (c) 2010 Elsevier B.V. All rights reserved.