Bioinspired synthesis of nanofibers on monolithic scaffolds for enzyme immobilization with enhanced loading capacity and activity recovery

BACKGROUND: The enzymatic process in continuous flow reactors has become attractive owing to the merits of in‐line purification, improved mixing and mass transfer, etc. However, the construction of continuous flow reactors requires stable and surface‐active monolithic scaffolds for enzyme immobilization. RESULTS: In this study, nanofibers of linear polyethyleneimine (LPEI) are formed on the surface of poly(sodium 4‐styrenesulfonate) (PSS)‐treated cordierite honeycomb (named LPEI/PSS cordierite‐H) as monolithic scaffold for enzyme immobilization. The controlled self‐assembly of LPEI ensures the formation of nanofibers (diameters of 20–80 nm) on the surface of cordierite‐H, which roughens the surface and offers many active sites for enzyme loading. The electrostatic interaction between negatively charged enzyme and positively charged LPEI helps the enzyme firmly attach on the surface. The loading capacity of LPEI/PSS cordierite‐H was 1.24 mg g⁻¹. Horseradish peroxidase (HRP)‐loaded LPEI/PSS cordierite‐H (HRP@LPEI/PSS cordierite‐H) exhibited activity recovery of 55.33%, 2‐fold higher than that of HRP‐loaded branched polyethyleneimine (BPEI)/PSS cordierite‐H (HRP@BPEI/PSS cordierite‐H) (23.72%). Furthermore, a silica layer was formed on the surface of HRP@LPEI/PSS cordierite‐H through LPEI‐induced silicification, which could prevent the enzyme from deactivation under extreme conditions. CONCLUSION: These monolithic biocatalysts have great potential for applications in wastewater treatment and even in other fields such as pharmaceutical synthesis. © 2019 Society of Chemical Industry