2-D/2-D heterostructured biomimetic enzyme by interfacial assembling Mn3(PO4)2 and MXene as a flexible platform for realtime sensitive sensing cell superoxide

It is critical for fabricating flexible biosensors with both high sensitivity and good selectivity to realize real-time monitoring superoxide anion (O-2(center dot-)), a specific reactive oxygen species that plays critical roles in various biological processes. This work delicately designs a Mn-3(PO4)(2)/MXene heterostructured biomimetic enzyme by assembling two-dimensional (2-D) Mn-3(PO4)(2) nanosheets with biomimetic activity and 2-D MXene nanosheets with high conductivity and abundant functional groups. The 2-D nature of the two components with strong interfacial interaction synergistically enables the heterostructure an excellent flexibility with retained 100% of the response when to reach a bending angle up to 180 degrees, and 96% of the response after 100 bending/relaxing cycles. It is found that the surface charge state of the heterostructure promotes the adsorption of O-2(center dot-), while the high-energy active site improves electrochemical oxidation of O-2(center dot-). The Mn-3(PO4)(2)/MXene as a sensing platform towards O-2(center dot-) achieves a high sensitivity of 64.93 mu A.mu M-1.cm(-2), a wide detection range of 5.75 nM to 25.93 mu M, and a low detection limit of 1.63 nM. Finally, the flexible heterostructured sensing platform realizes real-time monitoring of O-2(center dot-) in live cell assays, offering a promising flexible biosensor towards exploring various biological processes.

Automated summary

This study presents a flexible Mn-3(PO4)(2)/MXene heterostructured biomimetic enzyme for real-time monitoring of superoxide anion, exhibiting excellent flexibility, high sensitivity, and wide detection range toward O-2(center dot-).