A novel nanosensor for detecting tetracycline based on fluorescent palladium nanoclusters

Tetracycline (TC) is considered one of the most widely used antibiotic medicines, and ranks the second highest in global production and usage among all antibiotics. In this study, palladium nanoclusters (Pd NCs) have been successfully synthesized using polyvinylpirrolidone (PVP) as a capping agent and an ultrasensitive photoluminescent nanosensor for TC, and was first constructed based on an internal filtration effect causing fluorescence quenching of Pd NCs. The as-synthesized Pd NCs have high fluorescence intensity, good stability at extreme pH, high ionic strength, and excellent stability in light (under UV irradiation), and its fluorescence quantum yield (QY) was up to 5.9%. The fluorescence ratio of I/I0 linearly decreases with the increase in the concentrations of TC in the range from 0 nM to 220 nM in an aqueous buffer with the detection limit of 0.03 nM. The ultrasensitive detection of TC was also successfully realized in the spiked samples of honey with good recoveries. The advantages of this method include simplicity, rapidity, high sensitivity, high selectivity and cost efficiency.