Boronate affinity-based ratiometric fluorescent quantum dot sensors for the rapid detection of streptomycin from food

Streptomycin (STR), an aminoglycoside-class antibacterial agent, exerts potent antibacterial activity and finds extensive application in veterinary therapeutics and agricultural practices. Nevertheless, the growing improper utilization of STR may lead to persistent residual contamination in food products. This necessitates the development of accurate and reliable quantification methods for STR residues in food matrices. The present study establishes a dual-emission ratiometric fluorescence sensing platform using boronic acid-functionalized CdTe quantum dots with well-defined emission characteristics (APBA@g-r-CdTe QDs) for the specific identification of STR. Compared with traditional single-wavelength fluorescence techniques, this novel strategy exhibits significantly improved analytical performance, featuring enhanced stability and good measurement reproducibility. The developed sensor exhibited an expanded linear detection range spanning 0.01-105 µM concentration levels while achieving a rapid response within 5 minutes. The calculated limit of detection (LOD) reached 3.1 × 10^-9 mol L^-1 (0.45 mg kg^-1), indicating good sensitivity. Furthermore, compared with traditional single-emission fluorescence techniques, the developed boronate affinity-based ratiometric fluorescent probe based on CdTe quantum dots demonstrated improved resistance to environmental interference through its dual-emission sensing mechanism. This analytical system achieved accurate quantification of streptomycin (STR) in complex food matrices including dairy products, tea infusions, and poultry-derived samples, with spiked recoveries ranging from 92.0% to 113.0% across different food types. This study provides a rapid and efficient fluorescence detection tool for cis-diol-containing antibiotics in real samples.