Interwoven Porous ZIF Polyhedra Threaded with Silver Thiolate Nanowires for Ultrasensitive SERS Detection of Chlorotoluene Isomers

The identification of isomeric organic compounds poses a significant challenge due to their structurally and chemically analogous features. This research introduces an innovative methodology for the detection of chlorotoluene isomers through the utilization of Surface-Enhanced Raman Spectroscopy (SERS). The approach utilizes an exceptionally efficient SERS substrate, namely (Ag⁰ ₂Ag^IMpy)_n@h-ZIF (where Mpy denotes p-mercaptopyridine), characterized by its hollow Zeolitic Imidazolate Frameworks (h-ZIFs) interwoven with silver thiolate nanowires. The porous channels within h-ZIFs stably adsorb various chlorotoluene isomers, subsequently exposing them to the electromagnetic field generated by Ag⁰ species. In addition to coordinating with silver ions, the Mpy component within the silver nanowires functions as a highly stable SERS probe, which improves detection accuracy by serving as an internal standard. This study introduces a novel Ag-ZIF model as a highly efficient SERS substrate and presents a distinctive methodology for differentiating organic isomers or analogous small molecules.