By controlling the pH of the solution

single-layer dopamine modified multiwalled carbon nanotubes (micaDA-MWCNTs) were prepared under acid condition. Multiwalled carbon nanotubes/chitosan (CS/micaDA-MWCNTs) composites were prepared by covalent grafting method with glutaraldehyde as a bridge material between chitosan and multi-walled carbon nanotubes (MWCNTs). The structure and nature of CS/micaDA-MWCNTs composites were characterized by transmission electron microscope (TEM)

Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The results showed that about 6 nm membrane layer of chitosan was well-distributively coated on the surface and the end of MWCNTs. The effective biocompatible strategy of dopamine monolayer film coated carbon nanotubes can not only achieve the purpose of modification with less damage of carbon nanotube structure

but also increase significant amounts of surface active groups of MWCNTs

thereby increasing the content of grafted chitosan. Thermogravimetry analysis (TGA) data showed the chitosan graft was approximately 71.78%. CS/micaDA-MWCNTs had the advantages of both CS and MWCNTs in bacteriostasis

sustained-release effect and diatom growth inhibition. Antifouling experiments indicated that the composites had an efficient broad-spectrum of antibacterial activity against E. coli

S. aureus

Vibrio anguillarum

Navicula parva and Navicula rows.