ZIF-8/AuAg Nanocluster Composite as Fluorescent Sensor for Highly Sensitive and Selective Detection of Tetracycline

Abstract

Tetracycline (TC) residues pose substantial risks to environmental ecology and food safety, underscoring the need for sensitive and reliable detection technologies. This study developed a high-performance fluorescent probe by integrating bimetallic gold-silver nanoclusters (AuAg NCs) with zeolitic imidazolate framework (ZIF-8). The composite (ZIF-8/AuAg NCs) was fabricated via wet impregnation, where AuAg NCs anchored onto the ZIF-8 surface, forming an oriented monolayer. This structure conferred enhanced stability and through a confinement effect, significantly boosted the fluorescence intensity and quantum yield of the NCs by restricting ligand motion. The composite served as an excellent sensor for TC, exhibiting fluorescence quenching with high sensitivity and selectivity against common interferents. Practical applicability was confirmed in spiked real samples with satisfactory recoveries. The quenching mechanism was elucidated as a synergy of excitation light competition and photoinduced electron transfer. This work provides a robust strategy for constructing stable MOF-NC fluorescent platforms, holding great potential for trace antibiotic monitoring in environmental and food safety contexts.