Simultaneous Enhancement of Bioactivity and Stability of Laccase by Cu 2+/PAA/PPEGA Matrix for Efficient Biosensing and Recyclable Decontamination of Pyrocatechol

Anal Chem. 2017 Feb 7;89(3):2065-2072. doi: 10.1021/acs.analchem.6b04691. Epub 2017 Jan 11.

Abstract

Simultaneously enhancing the catalytic bioactivity and stability of enzyme is still an intractable issue in the enzymatic study. Herein, a facile and effective approach was designed to immobilize and modify laccase on a Cu2+-adsorbed pyrene-terminated block copolymer [poly(acrylic acid)/poly(poly(ethylene glycol) acrylate)] (PAA/PPEGA), which was prepared via well-controlled reversible addition-fragmentation chain transfer polymerization. PAA provided the supporting matrix for firm immobilization of Cu2+, an enzyme bioactivity inducer, onto the microstructure of laccase, while avoiding any contamination of the heavy metal Cu2+ into the following application system. The water-soluble, biocompatible, and nontoxic PPEGA was used as an ideal modifier to improve the laccase stability. Accordingly, the modified laccase exhibited enhanced catalytic bioactivity and stability simultaneously to 447% and 237%, respectively. The modified laccase was immobilized on the highly oriented pyrolytic graphite surface and large-area graphene papers through π-π stacking interactions between the pyrene moiety of PAA/PPEGA and the π-conjugated graphenelike surface. The as-prepared portable solid-state electrochemical laccase biosensor showed lowest detection limit of 50 nM (S/N ≥ 3) and long-term stability for pyrocatechol detection. Besides, the laccase immobilization on graphene paper provided efficient pyrocatechol decontamination platform with convenience and recyclability, which could retain the laccase bioactivity of 176% after 8 consecutive operations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins / chemistry*
  • Biosensing Techniques*
  • Catechols / metabolism*
  • Copper / metabolism*
  • Decontamination / methods*
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Stability
  • Laccase / metabolism*
  • Limit of Detection
  • Microscopy, Electron, Transmission
  • Polyethylene Glycols / chemistry*
  • Polymerization
  • Proton Magnetic Resonance Spectroscopy
  • Pyrenes / chemistry
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Acrylic Resins
  • Catechols
  • Pyrenes
  • Polyethylene Glycols
  • Copper
  • pyrene
  • Laccase
  • catechol