A novel biosensor utilizing the peroxidase-like activity of bovine spleen ferritin for highly sensitive detection of tetracycline antibiotics

The traditional methods for detecting tetracycline antibiotics (TCs) residues in foods have limitations such as complexity of the operation, high energy consumption, and potential contamination. In this research, ferritin from the bovine spleen (BSF) was separated and identified. A biosensor for highly sensitive detection of TCs was established using peroxidase activity of the inner iron nanoparticle of BSF. TCs can be combined with the inner iron nanoparticle of BSF to further affect the substrate oxidation reaction catalyzed by it, resulting in color changes that can be monitored by UV-vis spectra. Under the optimal reaction conditions, the detection limits are 21.6 nM for oxytetracycline, 15.0 nM for tetracycline, 20.2 nM for chlortetracycline, and 20.1 nM for doxycy-cline, respectively. In conclusion, a novel biosensor which is green and stable for highly sensitive detection of TCs, and the potential pathway for the high-value utilization of visceral by-products were provided in this research.