Enzyme‐Engineered Metal‐Organic Frameworks for the Construction of Organophosphorus Pesticide Biosensor

Abstract Rational immobilization of fragile enzymes on a scaffold is an efficient protocol to achieve robust biocatalyst, yet the construction remains challenging due to the trade‐off between enzyme activity and framework environment. Herein, an enzyme‐engineered assembly strategy enabling the in situ fusion of acetylcholinesterase (AChE) into Zn‐based metal‐organic frameworks (Zn‐MOF‐74) during the rapid nucleation and crystal defect growth process, is demonstrated. The Zn‐MOF‐74 composites can offer a hydrophilic framework microenvironment for maintaining the biological state of AChE, with flower‐like porous structure that allows for boosting the mass transfer process of substrates and products. Impressively, the apparent activity of AChE can be well maintained 90% after encapsulation, and the AChE@Zn‐MOF‐74 composites produced excellent stability in inhospitable environments. Given the structural integration, a robust AChE@Zn‐MOF‐74‐based biosensor is constructed for the sensitive detection of chlorpyrifos (organophosphorus pesticides) with a detection limit of 1.0 ng mL⁻¹, enabling the monitoring of pesticide degradation extent in the water body. This study is anticipated to offer valuable insight into understanding the structure‐activity relationship of enzyme@MOF to encourage applications in the construction of robust biosensors for precision agriculture.