Visual and rapid detection of glyphosate in tea using a MOF-driven fluorescent paper sensor

To overcome the limitations of conventional enzymatic glyphosate (Glyp) detection methods, including enzyme environmental sensitivity, high cost, and limited enzyme sources, this study developed a portable paper-based fluorescence platform (Y-R membrane) based on a metal-organic framework (MOF)-driven fluorescence regulation mechanism for non-enzymatic and rapid detection of Glyp. This platform was constructed by immobilizing MnMOF and yellow carbon dots (Y-CDs) on a polyvinylidene fluoride membrane. The ZrOx-OH derived from alkaline-treated UiO-66 regulated the Mn³⁺/Mn²⁺ redox reactions through its surface hydroxyl groups, triggering the red fluorescence of MnMOF. Glyp detection was achieved via competitive binding of its carboxyl groups to ZrOx-OH hydroxyls, inhibiting the redox process and inducing concentration-dependent fluorescence quenching. Coupled with RGB analysis, this platform exhibited excellent linearity (R² = 0.993) within 0.1-100 μg/mL range, with a detection limit of 0.06 μg/mL. The standard addition experiments demonstrated Glyp detection recoveries of 96.0 %∼103.4 % in tea samples, completing detection within 15 min. This platform enabled rapid, accurate and visual screening of Glyp residues without needing enzymatic reactions or sophisticated instruments. With its advantages of operational simplicity, cost-effectiveness, and intuitive readout, this system offered a novel competitive reaction-based sensing strategy for on-site rapid screening of Glyp in agricultural products.