SERS Analysis of Multiple Halogenated Phenols via Hydrogen Bond Enhanced Halogen Bond

The widespread use and environmental persistence of halophenols have raised severe ecological and health concerns, necessitating rapid and robust monitoring methods in complex water environments. In this study, we propose a novel SERS analytical strategy with multiplexing potential for the selective recognition and simultaneous screening of halophenols based on a hydrogen bond enhanced halogen bond (HBeXB) mechanism. By in situ coassembling a long-chain hydrophobic regulator and a nitrogen-containing heterocyclic probe (4-mercaptopyridine) onto a three-dimensional silver-coated copper foam, a synergistic dual-component recognition layer was constructed. The highly hydrophobic microenvironment effectively repels polar hydration interference, while the 4-mercaptopyridine probe leverages the highly directional HBeXB mechanism to selectively capture halophenol congeners acting as dual hydrogen-bond and halogen-bond donors. Driven by the distinct polarizabilities of different halogen atoms (I > Br > Cl), the probe exhibits monotonic Raman frequency shifts, enabling reliable physical fingerprinting for decoupling structurally similar analogues. The proposed method demonstrates reliable SERS responses toward four typical halogenated phenol congeners alongside anti-interference capabilities against various environmental interferents, achieving quantitative detection of tribromophenol with a lower detection limit of 50 nM. This strategy offers a promising technical avenue for the continuous screening and early risk warning of emerging pollutants.