Antibiotic quantitative fluorescence chemical sensor based on Zn-MOF aggregation-induced emission characteristics

Abstract

Antibiotic residues in water and food can aggravate the development of antibiotic-resistant bacteria. As a result, that is critical to creating a practical approach for detecting leftover antibiotics in a timely and sensitive manner. This research utilize the water instability of MOFs, and uses the zinc-based metal–organic framework of tetra (4-carboxyphenyl) ethylene (Zn-TCPE) as the sensing unit to create a new fluorescence sensing platform based on multiple colorimetric responses for ultra-fast and sensitive detection of tobramycin. Due to poor water stability, Zn-TCPE with aggregation-induced emission (AIE) would break into untidy pieces following immersion in aqueous solution. More importantly, the fluorescence of the Zn-TCPE aqueous solution was dimmed because the crystal framework of the Zn-TCPE was destroyed by the coordination of water molecules, causing the AIE-active organic linkers (H4TCPE) to undergo non-radiative emission motion, implying underlying mechanism research in the fluorescence “turn-off-on” mode. Because hydrophilic functional groups such as amino and hydroxyl can coordinate with metal ions, the Zn-TCPE aqueous solution showed great sensitivity for the response of amino, hydroxyl, and ether groups. The coordinated coordination of amino, hydroxyl, and ether groups with Zn2+ explains the reaction mechanism, culminating in the full destruction of Zn-TCPE. With the crystal structure collapse of Zn-TCPE, the AIE organic linkers are freed and then reassemble to form emissive aggregates with increased fluorescence. Because aminoglycoside (AG) antibiotics have hydrophilic functional groups such as amino, hydroxyl, and ether groups, they are employed as a molecular model for study. Interestingly, the Zn-TCPE probe has a strong selectivity for distinguishing AG antibiotics sulfate from other antibiotics.