Tuning Atomically Dispersed Fe Sites in Metal–Organic Frameworks Boosts Peroxidase-Like Activity for Sensitive Biosensing

The two functional groups (nitro and amino) were introduced into MIL-101(Fe) for tuning the atomically dispersed metal active sites. Benefiting from both geometric and electronic effects, the nitro-functionalized MIL-101(Fe) shows a superior electronic structure of active sites and low reaction energy barrier for the HO* formation. Nitro-functionalized MIL-101(Fe)-based biosensor was successfully employed to detect acetylcholinesterase activity and organophosphorus pesticide.