A self-calibrating dual responsive platform for sensitive detection of sulfite and sulfonic derivatives based on a robust Hf(IV) metal−organic framework

A robust hafnium-based metal organic framework Hf-PBTA with sensitive and ratiometric dual-emissive fluorescence response towards sulfite and sulfonic derivatives, including antibiotic sulfamethazine, has been developed, which shows a fast detection of sulfite ions at a concentration as low as 76 ppb. The opposite response tendency from two radiative pathways towards aromatic sulfonic molecules and sulfite anion stems from the synergistic effect of pyridine protonation effect, π-π stacking interaction and intramolecular twist motion.