| Texto completo | |
| Autor(es): Mostrar menos - |
Dias, Clemerson F. B.
[1]
;
Araujo-Chaves, Juliana C.
[1, 2]
;
Mugnol, Katia C. U.
[1, 2]
;
Trindade, Fabiane J.
[3]
;
Alves, Oswaldo L.
[4]
;
Caires, Antonio C. F.
[1]
;
Brochsztain, Sergio
[3]
;
Crespilho, Frank N.
[5]
;
Matos, Jivaldo R.
[6]
;
Nascimento, Otaciro R.
[7]
;
Nantes, Iseli L.
[2]
Número total de Autores: 11
|
| Afiliação do(s) autor(es): | [1] Univ Mogi das Cruzes, CIIB, Mogi das Cruzes, SP - Brazil
[2] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Grp Nanoestruturas Biol & Mat Avancados NanoBioMA, Santo Andre, SP - Brazil
[3] Univ Fed ABC, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, Santo Andre, SP - Brazil
[4] Univ Estadual Campinas, Lab Quim Estado Solido, Campinas, SP - Brazil
[5] Univ Sao Paulo, IQSC, BR-13560970 Sao Carlos, SP - Brazil
[6] Univ Sao Paulo, Inst Quim, Lab Anal Termica Prof Dr Ivo Giolito, Sao Paulo - Brazil
[7] Univ Sao Paulo, Inst Fis, Grp Biofis Sergio Mascarenhas, Sao Carlos, SP - Brazil
Número total de Afiliações: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | RSC ADVANCES; v. 2, n. 19, p. 7417-7426, 2012. |
| Citações Web of Science: | 7 |
| Resumo | |
In the present paper, we report on the molecular interaction and photochemistry of TiO2 nanoparticles (NPs) and cytochrome c systems for understanding the effects of supramolecular organization and electron transfer by using two TiO2 structures: P25 TiO2 NPs and titanate nanotubes. The adsorption and reduction of cytochrome c heme iron promoted by photo-excited TiO2, arranged as P25 TiO2 NPs and as nanotubes, were characterized using electronic absorption spectroscopy, thermogravimetric analysis, and atomic force microscopy. In an aqueous buffered suspension (pH 8.0), the mass of cytochrome c adsorbed on the P25 TiO2 NP surface was 2.3 fold lower (0.75 mu g m(-2)) than that adsorbed on the titanate nanotubes (1.75 mu g m(-2)). Probably due to the high coverage of titanate nanotubes by adsorbed cytochrome c, the low amount of soluble remaining protein was not as efficiently photo-reduced by this nanostructure as it was by the P25 TiO2 NPs. Cytochrome c, which desorbed from both titanium materials, did not exhibit changes in its redox properties. In the presence of the TiO2 NPs, the photo-induced electron transfer from water to soluble cytochrome c heme iron was corroborated by the following findings: (i) identification by EPR of the hydroxyl radical production during the irradiation of an aqueous suspension of TiO2 NPs, (ii) impairment of a cytochrome c reduction by photo-excited TiO2 in the presence of dioxane, which affects the dielectric constant of the water, and (iii) change in the rate of TiO2-promoted cytochrome c reduction when water was replaced with D2O. The TiO2-promoted photo-reduction of cytochrome c was reverted by peroxides. Cytochrome c incorporated in the titanate nanotubes was also reversibly reduced under irradiation, as confirmed by EPR and UV-visible spectroscopy. (AU) | |
| Processo FAPESP: | 09/15558-1 - Interação entre biomoléculas e sistemas celulares com nanoestruturas 0D, 1D e 2D utilizando métodos eletroquímicos |
| Beneficiário: | Frank Nelson Crespilho |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 11/01541-0 - Desenvolvimento de bioanodos constituídos por glicose oxidase e frutose desidrogenase e suas formas recombinantes para aplicação em protótipos de biocélulas a combustível enzimáticas: geração de energia a partir da biomassa (cana-de-açúcar) |
| Beneficiário: | Frank Nelson Crespilho |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |