# Enhanced Recognition via Defect Engineered Amorphous Metal–Organic Framework for Sensitive and Stable Pesticide Biosensor

## TL;DR

A new biosensor using defect-engineered amorphous metal-organic frameworks detects pesticides with high sensitivity and stability in complex food samples.

## Contribution

A defect-engineered amorphous metal-organic framework encapsulates enzymes to enhance biosensor performance.

## Key findings

- AChE@AMOF-74 shows 3.4-fold higher catalytic activity than crystalline nanoarchitectures.
- The biosensor detects paraoxon with a detection limit of 0.05 ng·mL−1.
- The method enables on-site pesticide detection in complex food matrices.

## Abstract

Enzyme‐based biosensors with rapid and on‐site detection capabilities possess great potential for practical application. However, conventional enzyme immobilization strategies often enhance stability at the expense of substantial enzyme activity loss, thereby limiting the detection performance of enzyme‐based biosensors. Herein, a highly sensitive and robust biosensor is constructed based on defect‐engineered amorphous metal‐organic frameworks, enabling on‐site detection of organophosphate pesticides in complex food matrices. Defective acetylcholinesterase@amorphous metal‐organic frameworks (denoted as AChE@AMOF‐74) can be in situ tailored via a defect‐engineered strategy to provide a suitable microenvironment and obtain high porosity for enzyme encapsulation, while its porous architecture enhances the catalytic activity of immobilized enzyme. Impressively, the catalysis activity and target recognition ability of AChE@AMOF‐74 are 3.4‐fold and 5.6‐fold higher than those of nanoarchitectures with a regular crystalline structure. Benefiting from the structural advantages, a robust AChE@AMOF‐74‐based biosensor is constructed for the sensitive detection of pesticides, enabling quantitative analysis of paraoxon with a detection limit of 0.05 ng·mL−1 using an image processing algorithm. This work demonstrates the significant potential of AMOFs in constructing high‐performance enzyme‐based biosensors and has been successfully applied to detect pesticide in complex food matrices, providing a new protocol for on‐site application.

A defect‐engineered assembly strategy is reported for the in situ encapsulation of acetylcholinesterase (AChE) into amorphous MOF‐74, endowing the composite with superior catalytic activity and target recognition capability. Leveraging these structural advantages, a sensitive and stable biosensor is constructed for the detection of paraoxon pesticide.