A fluorescence ionic probe utilizing Cu2+ assisted competition for detecting glyphosate abused in green tea

Food fraud caused by the violation of glyphosate use in tea is frequently exposed, posing a potential health risk to consumers and undermining trust in food safety. In the work, an ionic fluorescent probe “[P 66614 ] [4HQCA]-Cu 2+ ( PHQCA-Cu 2+ )” was constructed using Cu 2+ and ionic liquids coordination through a competitive coordination strategy to detect glyphosate. This probe exhibited a prominent “turn-on” fluorescence response in glyphosate detection. PHQCA-Cu 2+   was destroyed by glyphosate with its strong coordination capability, and a new complex re-formed simultaneously between glyphosate and the Cu 2+ in it, where Cu 2+ served as an “invisible indicator” influencing fluorescence changes. Remarkably, PHQCA-Cu 2+   formed rapidly within 5 s, demonstrated exceptional sensitivity and selectivity, and satisfactory detection performance on paper strips impregnated with   PHQCA-Cu 2+ .   Importantly,   PHQCA-Cu 2+   showed excellent recoveries in various green tea, which offered a viable method for identifying contaminated products from the supply chain quickly to enhance overall food safety surveillance.