title: Fabrication of oriented poly-L-lysine/bacteriorhodopsin-embedded purple membrane multilayer structure for enhanced photoelectric response.
abstract: A poly-L-lysine (PLL)/bacteriorhodopsin-embedded purple membrane (bR-PM) multilayer film has been successfully constructed by a layer-by-layer (LbL) assembly process to enhance the photoelectric response of bR. The assembly conditions were investigated and optimized. The PLL/bR-PM adsorption process was in situ studied by surface plasmon resonance and the growth of multilayer was further characterized by UV-vis absorption spectroscopy. The results indicate that the amount of adsorbed bR-PM vs. the assembled layer number exhibits linear relationship. The atomic force microscopy images of sequentially assembled PLL/bR-PM bilayers show that the patch structure of bR-PM in the structure is well preserved and the roughness increases with increase of the bilayer number. The peak photocurrent generated from PLL/bR-PM film increases with increase of the PLL/bR-PM bilayers until achieving a maximum value. The photocurrent of bR-PM from the film through PLL assembler is higher than those assembled by other polycations, thus rendering a new platform to effectively enhance the bR photoelectric responses.
authors.affiliation: School of Chemical and Biomedical Engineering & Center for Advanced Bionanosystems, Nanyang Technological University, 70 Nanyang Dr., Singapore 637457, Singapore.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Cui
authors.forename: Weihua
authors.initials: W
authors.lastname: Hu
authors.forename: Zhisong
authors.initials: Z
authors.lastname: Lu
authors.forename: Chang Ming
authors.initials: CM
authors.lastname: Li
mesh_terms: D000327:Adsorption; D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000302:isolation & purification; D019617:Halobacterium salinarum / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D055668:Photochemical Processes; D011107:Polylysine / Q000737:chemistry*; D018717:Purple Membrane / Q000737:chemistry*; D013053:Spectrophotometry; D013499:Surface Properties
chemical_list: D011107:Polylysine; D001436:Bacteriorhodopsins