title: Gold nanoparticles bound on microgel particles and their application as an enzyme support.
abstract: Submicron-sized poly(N-isopropyl acrylamide)/polyethyleneimine core-shell microgels were prepared in aqueous media by using tert-butyl hydroperoxide (TBHP) as an initiator, and then the gold nanoparticles (∼8 nm) were formed on the surface of the microgels. The amino groups on the polyethyleneimine (PEI) chains act as the binder for the assembly of the gold nanoparticles/microgel complex. In aqueous media the microgels are highly stable with the gold nanoparticles on their extended PEI chains, and this multi-scale nanoparticle complex can be recovered from water and redispersed in water. The nanogold/microgel particles were conjugated with the enzymes horseradish peroxidase (HRP) and urease. It is found that under identical assay conditions the enzyme/nanogold/microgel systems exhibit enhanced biocatalytic activity over free enzymes in solution, especially at lower enzyme concentrations. In addition, compared to free HRP, the HRP/nanogold/microgel systems show higher activity at varied pHs and temperatures, as well as higher storage stability. Thus the novel nanogold/microgel particles can serve as an excellent support for enzymes.
authors: College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China.
authors: Jing
authors: J
authors: Xu
authors: Fang
authors: F
authors: Zeng
authors: Shuizhu
authors: S
authors: Wu
authors: Xinxing
authors: X
authors: Liu
authors: Chao
authors: C
authors: Hou
authors: Zhen
authors: Z
authors: Tong