SERSbased

SERS-based refers to systems and methods that rely on surface-enhanced Raman spectroscopy (SERS) to detect and analyze chemical species. SERS enhances the Raman scattering signal of molecules that are in close proximity to plasmonic metal surfaces, typically gold or silver nanoparticles or nanostructured films. The enhancement arises mainly from electromagnetic effects associated with localized surface plasmon resonances and, to a lesser extent, from chemical interactions between the analyte and the metal surface. This leads to substantial improvements in sensitivity, enabling detection from trace levels and, in some cases, single-molecule detection.

SERS-based platforms are used for chemical sensing, biomedical diagnostics, environmental monitoring, and food safety, among other applications. Common formats include colloidal nanoparticle assays, substrate-based SERS chips, SERS tags or beads for multiplexed detection, and immunoassays that couple SERS readouts to antigen–antibody interactions. SERS can be integrated with microfluidics, lateral flow devices, and portable spectrometers to enable rapid, in-field analysis.

Key considerations for SERS-based sensors include substrate reproducibility and stability, uniform enhancement, and calibration for quantitative work. Substrate design employs roughened metal surfaces, nanopatterned nanostructures, and core–shell nanoparticles to optimize hotspots—regions of intense electromagnetic field where signals are amplified. Challenges include batch-to-batch variability, background fluorescence, and potential heating effects under laser illumination.

Spectral data from SERS-based methods typically show characteristic Raman fingerprints with shifts in ranges typical for the analyte, enabling qualitative identification and, with proper calibration, quantitative measurements.