Sampling strategies for enhancing the analytical performance of a hybrid spectroscopy platform in biomedical applications

Abstract

Abstract Laser-Induced Breakdown Spectroscopy (LIBS) of liquids poses significant analytical challenges, especially for biological samples such as blood and saliva, where only limited volumes are available. Maximising spectral information from these scarce samples is therefore essential. Among various liquid sampling approaches, the drop-coating method has shown particular promise for efficient sample utilisation. This study focuses on advancing the drop-coating approach by integrating enhanced sampling and laser excitation strategies to improve spectral performance while preserving LIBS’s intrinsic advantages. Specifically, pulsed laser-based Surface-Enhanced LIBS (SELIBS) and Nanoparticle-Enhanced LIBS (NELIBS) techniques were employed to amplify signal intensity and detection sensitivity. Systematic optimisation of key experimental parameters revealed effective conditions for achieving reproducible and high-intensity spectra. The proposed methodology provides a practical approach to enhance LIBS performance for the trace-level analysis of limited-volume biological samples, laying the groundwork for sensitive, non-destructive diagnostics and forensic applications. Furthermore, this work implements a hybrid spectroscopic platform designed for comprehensive elemental and molecular diagnosis of biological samples. This integrated architecture utilises a dual-laser, single-spectrograph configuration that enables coordinated excitation and collection of LIBS and Raman signals. This configuration simplifies the experimental workflow, reduces alignment and calibration, eases the analysis process and enhances the depth of information that can be extracted from biological samples, yielding a more holistic, comprehensive chemical composition of limited-volume bio samples.