By in situ simultaneous polymerization of dopamine and hydrolytic polycondensation of 3-aminopropyltriethoxysilane in an aqueous solution, a novel hybrid polymer network coating on stainless steel was formed. The polydopamine and silica hybrid polymer (PDSHP) adhered strongly on the surface of stainless steel. The PDSHP film provides active catechol and primary amine groups. Branched polyethylenimine was grafted based on the PDSHP film. The structure and morphology of the multilayer coating were characterized by attenuated total reflectance Fourier transform infrared spectroscopy reflectance, X-ray photoelectron spectroscopy, and atomic force microscopy and scanning electron microscopy images. The coatings on the stainless steel substrates exhibited anticorrosion of seawater. By making use of the primary amine groups on the multilayer coating, a biocidal agent 3chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) was grafted. The grafted CHPTAC was effective in killing bacteria, extending the multilayer polymer coating with biocidal functionality.

D-amino acid oxidase (DAAO) and catalase (CAT) have been genetically modified by fusing them to an elastin-like polypeptide (ELP). ELP-DAAO and ELP-CAT have been separately immobilized on multi-walled carbon nanotubes (MWNTs). It has been found that the secondary structures of the enzymes have been preserved. ELP-DAAO catalyzed the oxidative deamination of D-alanine, and H 2 O 2 was evolved continuously. When the MWNT-supported enzymes were used together, the generated hydrogen peroxide of ELP-DAAO could be decomposed in situ. The catalytic efficiency of the two immobilized enzymes was more than five times greater than that of free ELP-DAAO when the ratio of immobilized ELP-CAT to immobilized ELP-DAAO was larger than 1:1.