CoO/CuO hollow nanocage hybrids with high oxidase-like activity for biosensing of dopamine.

Here, we report the synthesis, characterization, and oxidase-like activity of CoO/CuO hollow nanocage (HNC) nanocomposites. The CoO/CuO HNCs were successfully prepared by hydrothermal treatment of ZIF-67 in copper nitrate solution, followed by carbonization in air. The obtained nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction.

Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential.