Detection of Glyphosate Based on <italic>In Situ</italic> Formation of Fluorescent Polymer Nanoparticles

A convenient and sensitive fluorescent sensor was successfully constructed for quantitative determination of glyphosate based on the in situ formation of fluorescent polymer nanoparticles (FPNPs) through Cu2+-triggered polymerization and the strong coordination interaction between Cu2+ and glyphosate. Cu2+ initiated the rapid copolymerization of dopamine (DA) and m-phenylenediamine (MPD), leading to the formation of FPNPs. However, when glyphosate was present, it coordinated with Cu2+, which significantly inhibited the formation of FPNPs, resulting in a decrease of the fluorescence intensity of the system. Consequently, fluorescent detection of glyphosate was achieved based on the Cu2+-DA-MPD system. Under the optimal experimental conditions, the method exhibited a linear detection range of 5–95 μmol/L with a limit of detection as low as 1.75 μmol/L (S/N=3). It also demonstrated high selectivity and excellent anti-interference capability. When this method was employed for detection of glyphosate in actual water samples, spiked recoveries between 97.8% and 103.3% were obtained, demonstrating its reliable practicality and substantial application potential in real sample analysis. Moreover, this method did not require the pre-preparation of fluorescent materials, offering a new idea for rapid detection of glyphosate.