A groundbreaking fluorescent sensor system developed by researchers at the Hefei Institutes of Physical Science offers a rapid and visual method for detecting phoxim, a widely used organophosphorus pesticide posing risks to food safety and the environment. Led by Prof. JIANG Changlong, the team engineered a novel supramolecular probe combining a flavonoid-based fluorescent dye (BFL) with whey protein, marking a significant advance in portable pesticide detection.
Traditional detection methods such as gas chromatography–mass spectrometry (GC–MS) deliver high precision but are hampered by their reliance on bulky instrumentation and intricate sample preparation, restricting their application in field-based screening. The new probe sidesteps these limitations through an elegant molecular design that exploits competitive binding interactions to generate an immediate visual signal.
At the core of the system is the BFL molecule, which fluoresces strongly upon binding with whey protein due to alterations in the local environment enhancing its emissive properties. When phoxim is introduced, it competitively disrupts this binding, causing fluorescence quenching and a visible transition from green fluorescence to complete colorlessness. This fluorescence “turn-off” provides a direct and rapid indication of pesticide presence without the need for complex instrumentation.
The BFL@WP sensor exhibits a concentration-dependent fluorescence response within a 0 to 130 nM range, boasting a detection limit as low as 1.143 nM in solution. Furthermore, it maintains remarkable selectivity against common ionic interferences, enabling accurate detection even in complex matrices. Fast response times add to its suitability for real-time monitoring applications.
To enhance user accessibility, the research team translated the sensor into a paper-strip format coupled with a smartphone-based readout platform. Under ultraviolet illumination, fluorescent signals on the strip can be captured and analyzed through smartphone imaging software by quantifying RGB channel changes, allowing for straightforward, on-the-spot quantitative analysis. The paper-strip sensor exhibits a detection sensitivity down to 3.277 nM and shows reliable performance when tested in real-world samples including tap water, lake water, and fruit juice.
This innovation reflects a promising shift towards portable, low-cost, and user-friendly pesticide monitoring, with the potential to revolutionize on-site food safety inspections and environmental surveillance. Its simple operation and rapid visual feedback empower non-expert users to perform critical pesticide screening, thereby advancing public health protections and environmental stewardship.
The integration of supramolecular chemistry with widely available biomaterials such as whey protein exemplifies an effective strategy for designing advanced sensors. This study not only showcases impressive technical achievement but also opens avenues for future sensor development targeting other hazardous compounds with similar competitive binding mechanisms.
Through bridging sophisticated fluorescence sensing with accessible technology, the team at Hefei Institutes of Physical Science has created a tool with real-world relevance that could reshape rapid monitoring paradigms in agriculture and environmental management.
Subject of Research: Rapid fluorescent detection of organophosphorus pesticide phoxim using supramolecular sensor systems.
Article Title: Rapid Visual Detection of Phoxim Via Competitive Binding in a Flavonoid-Based Fluorescent Dye@Whey Protein Sensor
News Publication Date: 15-May-2026
Image Credits: LIU Anqi
Keywords
Fluorescent sensor, Phoxim detection, Organophosphorus pesticide, Supramolecular probe, Whey protein, Flavonoid dye, Rapid screening, Portable pesticide detection
