Polydopamine-mediated synthesis of core-shell gold@calcium phosphate nanoparticles for enzyme immobilization

Biomater Sci. 2019 Jun 25;7(7):2841-2849. doi: 10.1039/c9bm00283a.

Abstract

Considerable efforts have been made to develop reliable immobilization approaches to improve enzyme stability and reusability. However, relatively complicated preparation often leads to compromised enzyme activity. This study reports a facile method of retaining full enzymatic activity by immobilizing glucose oxidase (GOx) into core-shell nanoparticles with polydopamine (PDA) sandwiched between a gold nanoparticle (Au NP) core and a calcium phosphate (CaP) shell (Au@PDA@CaP). The strong adhesion of PDA on Au NPs and its metal chelating properties directed the preferential growth of the CaP shell on the Au NPs, leading to well-dispersed and uniform nanohybrids. Concurrent loading of GOx during the growth of CaP held the key to the successful immobilization of GOx. As a result, Au@PDA@CaP-immobilized GOx had similar activity but better resistance against heating, long-term storage and repeated uses compared to free GOx. This work provides a green strategy for constructing nanobiocatalysts with high enzyme activity and stability.

MeSH terms

  • Biocatalysis
  • Calcium Phosphates / chemistry*
  • Chemistry Techniques, Synthetic
  • Enzyme Stability
  • Enzymes, Immobilized / chemistry*
  • Enzymes, Immobilized / metabolism
  • Glucose Oxidase / chemistry*
  • Glucose Oxidase / metabolism
  • Gold / chemistry*
  • Hydrogen-Ion Concentration
  • Indoles / chemistry*
  • Nanoparticles / chemistry*
  • Nanotechnology*
  • Polymers / chemistry*
  • Temperature

Substances

  • Calcium Phosphates
  • Enzymes, Immobilized
  • Indoles
  • Polymers
  • polydopamine
  • Gold
  • calcium phosphate
  • Glucose Oxidase