One-step synthesis of a Tb-PET MOF for quantitative visual sensing of Anthrax biomarker

Novel strategies for the sensitive and rapid detection of the anthrax biomarker (2,6-pyridinedicarboxylic acid, DPA) are critical for ensuring food safety and preventing the disease. In this study, a novel fluorescent metal-organic framework (MOF) was fabricated via a directly from waste polyethylene terephthalate (PET) plastic. The sensor exhibited excellent pH stability (pH = 2-10), ultrafast response (within 5 s), a low detection limit (0.15 μM), and strong anti-interference performance. Spectroscopic and DFT studies confirmed that the fluorescence enhancement originates from DPA chelation with Tb³⁺, where DPA acts as an efficient energy-transfer antenna. Building on this mechanism, we demonstrated the immediate visual detection of DPA in tap water, tea, and milk using the MOF solution under UV light. Furthermore, quantitative analysis of DPA in milk was performed via a smartphone-based assay, thereby establishing a rapid, accurate, and practical method for on-site detection.