2D MoS₂ plasmonic nanocavity based SERS platform for bilirubin detection.

This article focuses on the development of a highly sensitive surface enhanced Raman spectroscopy (SERS) platform for detecting bilirubin (BR) at ultralow sub-nanomolar concentrations, which is important due to bilirubin's association with chronic heart, lung, and neurological disorders. The study introduces a plasmonically active two-dimensional molybdenum disulfide (2D MoS₂) based SERS substrate combined with a gold (Au) film to form a plasmonic nanocavity that effectively suppresses fluorescence interference via Förster resonance energy transfer (FRET), enabling reliable detection of BR down to 0.1 nM. Calibration of BR concentration is achieved by referencing stable citrate peaks from gold nanoparticle synthesis, allowing linear quantification across picomolar to micromolar ranges. This approach offers a simplified, one-step method with enhanced sensitivity compared to traditional substrates and holds promise for early diagnosis of diseases linked to low bilirubin levels, with future work aimed at validating the platform in biological samples such as blood serum and urine.