Coupling of in-tube SPME and SERS for ultrafast screening of hydrophobic pollutants in aqueous matrices

In-tube SPME-SERS platform enables rapid pollutant screening. • Dynamic flow enhances mass transfer and extraction capacity. • Sampling, enrichment, and detection are completed within 3 min. • The method successfully screens multiple hydrophobic pollutants in water. Background Given the persistence, bioaccumulation, and toxicity of hydrophobic pollutants (HPs), rapid and reliable screening methods are critically needed. Herein, we propose an integrated approach coupling surface-enhanced Raman spectroscopy (SERS) with in-tube solid-phase microextraction (in-tube SPME) for the rapid screening of HPs. The device integrates a dual-functional substrate (tert-dodecylthiol-modified silver nanostructures) within a quartz capillary and a syringe pump for flow control. During analysis, sample solutions are pumped through the capillary, enabling rapid HP adsorption onto the substrate via hydrophobic interactions under continuous flow. Results This dynamic configuration enhances mass transfer efficiency, facilitating rapid SERS detection with a portable Raman spectrometer. The entire “sampling and detection” workflow of the in-tube SPME-SERS method can be completed within 3 min. This method exhibits a good linear relationship (R 2  = 0.997) for the quantitative determination of Sudan III over the concentration range of 5–100 nM, with a limit of detection (LOD) as low as 0.658 nM, demonstrating outstanding sensitivity. Furthermore, the method shows satisfactory performance in terms of spatial homogeneity, batch-to-batch reproducibility, and long-term stability. Significance By balancing speed and accuracy in environmental HP analysis, this work provides a robust framework for portable screening platforms with significant potential for ecological monitoring and exposome research. Download: Download high-res image (211KB) Download: Download full-size image