Synergistic combination of convective self-assembly and hollow core fiber for sensitive SERS detection of glucose molecules.

This study demonstrates a highly sensitive surface-enhanced Raman scattering (SERS) platform developed by integrating convective self-assembly (CSA) with hollow core fibers (HCFs). Traditional solid-core-based fiber-optic SERS probes, such as multi-mode fibers (MMFs), often suffer from limited light-matter interaction area and poor hot-spot generation. To overcome these limitations, we utilized the CSA to deposit plasmonic nanoparticles onto the long interior walls of the HCF. This architecture confines both the excitation laser and the target analyte within the micro-capillary core, dramatically extending the effective interaction volume. The analytical performance of the CSA-based HCF sensor was evaluated through quantitative glucose detection analysis. Our results reveal a remarkable sensitivity enhancement and a fairly good linearity across a broad physiological concentration range, ensuring precise glucose detection. The combination of the HCF's waveguide efficiency and the reliable hot-spot distribution achieved via CSA provides a robust, high-performance solution for trace-level biomolecular sensing. This platform holds significant potential for next-generation point-of-care diagnostics and metabolic healthcare monitoring.