A Portable Electrochemical\nBiosensor Based on an Amino-Modified\nIonic Metal–Organic Framework for the One-Site Detection of\nMultiple Organophosphorus Pesticides

Constructing stable, portable sensors and revealing their\nmechanisms\nis challenging. Ion metal–organic frameworks (IMOFs) are poised\nto serve as highly effective electrochemical sensors for detecting\norganophosphorus pesticides (OPs), leveraging their unique charge\nproperties. In this work, an amino-modified IMOF was constructed and\ncombined with near-field communication (NFC) technology to develop\na portable, touchless, and battery-free electrochemical biosensor <b>NH</b><sub><b>2</b></sub><b>-IMOF@CS@AChE</b>. -NH<sub>2</sub> in <b>NH</b><sub><b>2</b></sub><b>-IMOF</b> gives the framework a higher electropositivity compared to <b>IMOF</b>, enhancing the electrostatic attraction with acetylcholinesterase\n(AChE), which is beneficial for immobilizing AChE. Furthermore, the\nuncoordinated O atoms and the (CH<sub>3</sub>)<sub>2</sub>NH<sub>2</sub><sup>+</sup> groups in <b>NH</b><sub><b>2</b></sub><b>-IMOF</b> help to form stronger bonds with AChE through hydrogen\nbonds. The results showed a wide linear response range of 1 ×\n10<sup>–15</sup> to 1 × 10<sup>–9</sup> M and a\nlow detection limit of 1.24 × 10<sup>–13</sup> M for glyphosate\n(Gly) in the practical detection of OPs. Additionally, electrochemical\nbiosensor arrays were constructed to effectively identify and distinguish\nmultiple OPs on the basis of their unique differential pulse voltammetry\n(DPV) electrochemical signals. This work provides a simple and effective\nsolution for on-site OP analysis and can be widely applied in food\nsafety and water quality monitoring.