High-sensitivity tetracycline detection with ring-cavity laser sensor enhanced by AgNPs@HOF-101@TC Apt/PDA functional film

In this study, a silver nanoparticles@hydrogen-bonded organic framework-101@tetracycline aptamer/polydopamine (AgNPs@HOF-101@TC Apt/PDA)-modified fiber ring laser (FRL) sensor is fabricated for the detection of tetracycline (TC). By cascading a microfiber interferometer (MFI) and a fiber Bragg grating (FBG) into the FRL system, the detection of TC concentration is realized by measuring the wavelength shift of the output laser, with simultaneous temperature compensation. The sensor exhibits a broad response range of 0.001-1000 nM, a linear range of 0.001-0.01 nM, a sensitivity of 219.44 nm/nM, and a limit of detection (LOD) of 0.52 pM. Recoveries in real samples (tap water, river water, milk and honey) range from 82.16% to 116.62%. A support vector regression (SVR) model is used to predict the TC concentration, with a coefficient of determination (R²) reaching 0.9937. With its high sensitivity and excellent stability, this sensor provides a reliable technical solution for the detection of antibiotic residues.