A Portable Electrochemical Biosensor Based on an Amino-Modified Ionic Metal–Organic Framework for the One-Site Detection of Multiple Organophosphorus Pesticides

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.