A further insight into the biosorption mechanism of PtIV by infrared spectrometryReport as inadecuate




A further insight into the biosorption mechanism of PtIV by infrared spectrometry - Download this document for free, or read online. Document in PDF available to download.

BMC Biotechnology

, 9:62

First Online: 06 July 2009Received: 26 November 2008Accepted: 06 July 2009

Abstract

BackgroundPlatinum nanomaterial is one of the significant noble metal catalysts, and the interaction of platinum with microbe is one of the key factors in influencing the size and the distribution of the platinum nanoparticles on the microbial biomass. Some properties of PtIV adsorption and reduction by resting cells of Bacillus megatherium D01 biomass have once been investigated, still the mechanism active in the platinum biosorption remains to be seen and requires further elucidating.

ResultA further insight into the biosorption mechanism of PtIV onto resting cells of Bacillus megatherium D02 biomass on a molecular level has been obtained. The image of scanning electron microscopy SEM of the D02 biomass challenged with PtIV displayed a clear distribution of bioreduced platinum particles with sizes of nanometer scale on the biomass. The state of PtIV bioreduced to elemental Pt0 examined via X-ray photoelectron spectroscopy XPS suggested that the biomass reduces the PtIV to PtII followed by a slower reduction to Pt0. The analysis of glucose content in the hydrolysates of D02 biomass for different time intervals using ultraviolet-visible UV-vis spectrophotometry indicated that certain reducing sugars occur in the hydrolyzed biomass and that the hydrolysis of polysaccharides of the biomass is a rapid process. The infrared IR spectrometry on D02 biomass and that challenged with PtIV, and on glucose and that reacted with PtIV demonstrated that the interaction of the biomass with PtIV seems to be through oxygenous or nitrogenous chemical functional groups on the cell wall biopolymers; that the potential binding sites for Pt species include hydroxyl of saccharides, carboxylate anion and carboxyl of amino acid residues, peptide bond, etc.; and that the free monosaccharic group bearing hemiacetalic hydroxyl from the hydrolyzed biomass behaving as an electron donor, in situ reduces the PtIV to Pt0. And moreover, the binding of the PtIV to the oxygen of the carbonyl group of peptide bond caused a change in the secondary structure of proteins; i.e. a transformation, in polypeptide chains, of β-folded to α-helical form; it might be expected to be more advantageous than β-folded form to the platinum nanoparticles under shelter from gathering although the both special conformations of proteins could be much probably responsible for the stabilization of the particles.

ConclusionThat knowledge could serve as a guide in the researches for improving the preparation of highly dispersive supported platinum catalyst and for fabricating new advanced platinum nanostructured devices by biotechnological methods.

Electronic supplementary materialThe online version of this article doi:10.1186-1472-6750-9-62 contains supplementary material, which is available to authorized users.

Ru Xue, Yiwen Ye, Jianhong Zheng and Zhenling Xu contributed equally to this work.

Download fulltext PDF



Author: Zhongyu Lin - Ru Xue - Yiwen Ye - Jianhong Zheng - Zhenling Xu

Source: https://link.springer.com/article/10.1186/1472-6750-9-62







Related documents