Biocompatible polypyrrole-block copolymer-gold nanoparticles platform for determination of inosine monophosphate with bi-enzyme biosensor

•A bi-enzyme biosensor system for determination of IMP was developed.•A novel PPy-F127-Au NPs with conductivity and biocompatibility was designed and synthesized.•The biosensor showed a linear range from 0.05 to 15 g/L.•The biosensor showed a low detection limit of 3.85 ng/mL.•The idea and method will provide a new approach for evaluation of freshness and quality of stored muscles.

Inosine monophosphate (IMP) is considered to be an important constituent in the formation and development of meat flavor. In this paper, a bi-enzyme biosensor system for determination of IMP was developed to evaluate the freshness and quality of stored muscles. More details of preparing for polypyrrole-Pluronic F127-gold nanoparticles (PPy-F127-Au NPs) and immobilizing bi-enzyme (peroxidase and 5′-nucleotidase) on PPy-F127-Au NPs modified glassy carbon electrode (GCE) were presented. The electrochemical behaviors of the bi-enzyme biosensor were analyzed, and the concentration of IMP was determined based on the bi-enzyme biosensor response. The results of linear sweep voltammetric (LSV) and square wave voltammetry (SWV) indicated that the catalytic reaction was occurred favorably on the surface of the bi-enzyme biosensor, with a wide detection range (0.05–15 g/L) and a low detection limit of 3.85 ng/mL. The good anti-interference ability, stability and repeatability of this biosensor were also proved. The analytical results by the biosensor system did correlate well with those obtained by liquid chromatography.