Hierarchically Porous Copolymer Film as Immobilization Matrix for Phenol Biosensor with High Sensitivity

A hierarchically porous structure of the matrix for immobilization of bioactive molecules is of crucial importance in improving the performance of electrochemical biosensors. In the present work, a block copolymer film was prepared via spinodal-decomposition-induced macro- and mesophase separation plus extraction by rinsing (SIM2PLE). The film exhibited an interconnected porous structure including macropores and mesopores. Thus, the specific surface area of the film was greatly enhanced, which was a benefit to the subsequent immobilization of enzyme. Then the resultant porous block copolymer film was adopted to construct a high-performance electrochemical biosensor to detect phenolic compounds. The as-developed phenolic biosensor exhibited a high sensitivity (3.0 × 103 mA·M–1·cm–2), quick response (<5 s), and extremely low detection limit (7 nM at an S/N ratio of 3). Moreover,a decent linear range (0.02–35 μM) was also observed. This work demonstrates that the hierarchically porous film based on copolymer prepared by SIM2PLE can serve as a versatile immobilization matrix and has promising applications in high-performance electrochemical biosensors.