A Portable Electrochemical Biosensor Based on an Amino-Modified Ionic Metal-Organic Framework for the One-Site...

Constructing stable, portable sensors and revealing their mechanisms is challenging. Ion metal-organic frameworks (IMOFs) are poised to serve as highly effective electrochemical sensors for detecting organophosphorus pesticides (OPs), leveraging their unique charge properties. In this work, an amino-modified IMOF was constructed and combined with near-field communication (NFC) technology to develop a portable, touchless, and battery-free electrochemical biosensor NH₂-IMOF@CS@AChE. -NH₂ in NH₂-IMOF gives the framework a higher electropositivity compared to IMOF, enhancing the electrostatic attraction with acetylcholinesterase (AChE), which is beneficial for immobilizing AChE. Furthermore, the uncoordinated O atoms and the (CH₃)₂NH₂⁺ groups in NH₂-IMOF help to form stronger bonds with AChE through hydrogen bonds. The results showed a wide linear response range of 1 × 10^-15 to 1 × 10^-9 M and a low detection limit of 1.24 × 10^-13 M for glyphosate (Gly) in the practical detection of OPs. Additionally, electrochemical biosensor arrays were constructed to effectively identify and distinguish multiple OPs on the basis of their unique differential pulse voltammetry (DPV) electrochemical signals. This work provides a simple and effective solution for on-site OP analysis and can be widely applied in food safety and water quality monitoring.