Yoonsung Oh, Juhan Hyun, Sungwook Yoon, Dahui Song, Jinhyuk Park
This study presents a versatile solid-phase microextraction-surface-enhanced Raman spectroscopy (SPME-SERS) fiber for qualitative screening of organic contaminants across different sample phases. The fiber was fabricated by incorporating polydimethylsiloxane-modified Ag-nanoaggregates (AgNA) into a porous poly(2,6-diphenyl-p-phenylene oxide) (PPPO) matrix coated on a metallic support. In this structure, the PPPO matrix provides a stable porous framework for AgNA distribution, while the AgNA interface simultaneously promotes analyte enrichment and SERS signal enhancement. The successful formation of the nanocomposite coating and its plasmonic properties were confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible analyses. The sensing performance of the SPME-SERS fiber was systematically evaluated using various organic contaminants, including cationic and anionic dyes, herbicides, and volatile organic compounds (VOCs). In liquid-phase analysis, characteristic SERS signals of rhodamine 6G, rose bengal, diquat, and 2,4-dichlorophenoxyacetic acid were successfully detected under aqueous and non-aqueous conditions. The fiber also enabled direct detection of dye molecules immobilized in a poly(vinyl alcohol)-glycerol gel matrix, demonstrating its applicability to solid matrix samples. Furthermore, gas-phase VOCs such as methyl salicylate and linalool were collected and discriminated based on their time-dependent SERS responses, with gas chromatography/flame ionization detection analysis supporting the interpretation of concentration-dependent trends. Real-sample screening using a topical analgesic and lavender tea further confirmed the practical feasibility of the platform. These results demonstrate that the proposed SPME-SERS fiber can serve as a simplified and adaptable analytical tool for qualitative screening of organic contaminants in liquid, gel, and vapor-phase environments.