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In this work, a chitosan/alginate multilayer film was constructed via layer-by-layer self-assembly and studied by in situ surface plasmon resonance monitoring and contact angle measurements. The results demonstrate that the surface composition of the self-assembled multilayer film can be simply tailored through pH control during the assembly process. The biological property of the assembled film was further characterized via antigen-antibody interactions, showing that the loading capacity of the antibody on the multilayered film and the binding activity of the antigen to the immobilized antibody could be also well-tuned by pH control. This work can provide more scientific insight in the interaction between protein and polymer matrix and render a novel simple approach to build high-performance biointerfaces through pH control for potential applications of highly sensitive immunosensors.

Phototoelectrochemical (PEC) water splitting represents a highly promising strategy to convert solar energy to chemical energy in the form of hydrogen, but its performance is severely limited by the water oxidation reaction. We conformally grew an ultrathin and continuous coating of Cu2O on TiO2 nanowire array (NWA) to form a truly core-shell TiO2@Cu2O NWA via a new facile, economical, and scalable polymer-mediated self-assembly approach, in which the polymer serves as a stabilizer, reductant, and linker simultaneously. This heteronanostructure was subsequently directly used as a photoanode for PEC water splitting, showing a photocurrent density of 4.66 mA cm(-2) at 1.23 V vs RHE in 0.5 M Na2SO4 solution and a maximum photoconversion efficiency of 0.71%, both of which are the highest reported for TiO2-based photoanodes measured under the same conditions (neutral conditions and without any sacrificial agent). The superior PEC performance of the TiO2@Cu2O NWA toward water oxidation is primarily due to much enhanced visible light collection and charge separation for high charge carrier density as well as greatly facilitated charge transfer and transport. This work not only offers a novel TiO2@Cu2O core-shell NWA photoanode for highly efficient PEC water oxidation and investigate its enhancement mechanism but also provides scientific insights into the mechanism of the polymer-mediated self-assembly, which can be further extended to fabricate various other core-shell nanoarchitectures for broad applications.

A multifunctional multilayered film containing TiO(2) nanoparticles as contact-active antibacterial agent and nanosilver as a release-active antibacterial agent was fabricated via layer-by-layer assembly. TiO(2) nanoparticles with the anatase crystalline dominant structure were synthesized via a sol-gel method. The QCM, AFM, and contact angle measurement results indicated that the TiO(2) nanoparticle-chitosan was successfully assembled with heparin via layer-by-layer assembly. The UV visible spectroscopy demonstrated that the silver ions could be loaded into the multilayers and in situ synthesize silver nanoparticles in the multilayers template. The short-term antibacterial assay showed the TiO(2)-chitosan/heparin multilayers loaded with nanosilver was bactericidal both in the low intensity UV light and in the dark. The long-term antibacterial assay indicated although the antibacterial in dark decreased with the PBS immersion time, the hybrid multilayered films sustained the long-term antibacterial in the low intensity UV light.