Distance-controlled surface-enhanced Raman spectroscopy of nanoparticles

Biological particles, e.g., viruses, lipid particles, and extra -cellular vesicles, are attracting significant research interest due to their role in biological processes and potential in practical applications, such as vaccines, diagnostics, and therapies. Their surface and interior contain many different molecules including lipids, nucleic acids, proteins, and car-bohydrates. In this Letter, we show how distance-controlled surface-enhanced Raman spectroscopy (SERS) is a promis-ing method to extract essential information from the spatial origin of the signal. This is a highly important parameter in the analysis of these biological particles. The principle of the method is demonstrated by using polystyrene (PS) beads as a biological particle model conjugated with gold nanospheres (AuNSs) functioning as distance-controlled SERS probes via biotin-streptavidin binding. By tuning the size of AuNSs, the Raman signal from the PS beads can be weakened while the signal from the biotin-streptavidin complex is enhanced.

Automated summary

Biological particles, such as viruses, lipid particles, and extra-cellular vesicles, have attracted significant research interest due to their important role in biological processes and potential applications in vaccines, diagnostics, and therapies. This study demonstrates the promise of distance-controlled surface-enhanced Raman spectroscopy (SERS) in extracting essential information from the spatial origin of the signal, which is a crucial parameter in the analysis of these biological particles. By using polystyrene beads as a model, the principle of the method is shown using gold nanospheres as distance-controlled SERS probes through biotin-streptavidin binding.