Graphdiyne: A new promising member of 2D all-carbon nanomaterial as robust electrochemical enzyme biosensor platform

Graphdiyne (GDY), a new two-dimensional all-carbon allotrope composed of benzene rings and alkyne unites, was successfully synthesized via a crossing-coupling reaction with much intriguing properties especially highly π-conjugated structure, attractive electronic and chemical properties, good biocompatibility and dispersion in aqueous solution. The as-prepared graphdiyne was explored for the first time as an extremely attractive matrix for tyrosinase (a model enzyme) immobilization to construct a mediator-free GDY-based biosensor for rapid detection of bisphenol A (BPA). The response of GDY-based tyrosinase biosensor is linear over the range of 1.0 × 10⁻⁷ to 3.5 × 10⁻⁶ mol L⁻¹ with a high sensitivity of 2990.8 mA cm⁻² M⁻¹ and a low detection limit of 24 nmol L⁻¹. The proposed GDY-based tyrosinase biosensor exhibited better analytical performances for BPA detection than CNTs and graphene based biosensors. The excellent performance of the biosensor should partially be ascribed to the strong π-π interactions between graphdiyne and BPA, which could enrich available BPA concentration on the electrode to react with tyrosinase. The robust GDY-based tyrosinase biosensor was used for BPA detection in drinking bottles and tap water with satisfactory results. As a new 2D all-carbon nanomaterial, graphdiyne is proved to be a powerful electrochemical enzyme biosensor platform for biomolecules (as recognition elements) immobilization and biosensor fabrication, and provides great application prospect for biomedical detection and environmental analyses.