Artículos de revistas
Amphiphilic porphyrin-cardanol derivatives in Langmuir and Langmuir-Blodgett films applied for sensing
Fecha
2013-05Registro en:
Colloids and Surfaces A, Amsterdam : Elsevier BV, v. 425, p. 68-75, May 2013
0927-7757
10.1016/j.colsurfa.2013.02.033
Autor
Sandrino, Bianca
Clemente, Claudenilson da Silva
Oliveira, Thiago Mielle Brito Ferreira
Ribeiro, Francisco Wirley Paulino
Pavinatto, Felippe José
Mazzetto, Selma Elaine
Lima Neto, Pedro de
Correia, Adriana Nunes
Pessoa, Christiana Andrade
Wohnrath, Karen
Institución
Resumen
This study presents the preparation of a nanostructured films with an amphiphilic meso-porphyrin whose side chains are derived from cardanol, a byproduct of the cashew industry. The Langmuir films were prepared on acidified water to reducing the self-aggregation of the complex and the mean molecular area for the meso-porphyrin measured by surface pressure isotherms was 177 Å2 and confirmed by compressibility modulus. The 700 nm band observed in the Langmuir films supports the coexistence of monomers and dimers similar to the spectra of the solution (CHCl3/CH3COOH). The formation of bright block domains with different sizes and shapes for the monolayer disappears after surface pressure starts to increase (π ≥ 2 mN m-1), as observed by Brewster angle microscopy measurements. Results of UV-vis spectra of the Langmuir films and FTIR reflection of the Langmuir-Blodgett (LB) films of meso-porphyrin indicated that the molecules exhibit preferential orientation with the planes perpendicular to the water (Langmuir) and parallel to the substrate (LB) surface. The LB films were tested as a promethazine sensor, which detected a concentration of 2 µM, a value greater than those obtained by other nanostructured systems.