Biomimetic superoxide dismutase stabilized by photopolymerization for superoxide anions biosensing and cell monitoring.

Photopolymerization strategy, as one of the immobilization methods, has attracted considerable interest because of some advantages, such as easy operation, harmlessness to the biomolecules, and long storage stability. (E)-4-(4-Formylstyryl) pyridine (formylstyrylpyridine) was prepared through Heck reaction and used as a photopolymer material to immobilize biomimetic superoxide dismutase under ultraviolet irradiation (UV) irradiation in a short time. The styrylpyridinium moiety of Formylstyrylpyridine was photoreactive and formed a dimer under UV irradiation. Mn2P2O7 multilayer sheet, a novel superoxide dismutase mimic, was synthesized. The formed photopolymer can immobilize Mn2P2O7 firmly under UV irradiation. On the basis of high catalytic activity of Mn2P2O7 biomimetic enzyme and long-term stability of Mn2P2O7-formylstyrylpyridine film, after introducing multiwalled carbon nanotubes (MWCNTs), a novel electrochemical biosensing platform called MWCNTs/Mn2P2O7-formylstyrylpyridine for superoxide anion (O2(•-)) detection was constructed. The biosensor displayed good performance for O2(•-) detection and provided a reliable platform to adhere living cells directly on the modified electrode surface. Therefore, the biosensor was successfully applied to vitro determination of O2(•-) released from living cells, which had a promising prospect for living cells monitoring and diagnosis of reactive oxygen species-related diseases.