Ultrabright gap-enhanced Raman tags for high-speed bioimaging.

ABSTRACT: Surface-enhanced Raman spectroscopy (SERS) is advantageous over fluorescence for bioimaging due to ultra-narrow linewidth of the fingerprint spectrum and weak photo-bleaching effect. However, the existing SERS imaging speed lags far behind practical needs, mainly limited by Raman signals of SERS nanoprobes. In this work, we report ultrabright gap-enhanced Raman tags (GERTs) with strong electromagnetic hot spots from interior sub-nanometer gaps and external petal-like shell structures, larger immobilization surface area, and Raman cross section of reporter molecules. These GERTs reach a Raman enhancement factor beyond 5?×?10⁹ and a detection sensitivity down to a single-nanoparticle level. We use a 370??W laser to realize high-resolution cell imaging within 6?s and high-contrast (a signal-to-background ratio of 80) wide-area (3.2?×?2.8?cm²) sentinel lymph node imaging within 52?s. These nanoprobes offer a potential solution to overcome the current bottleneck in the field of SERS-based bioimaging.

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC6715656 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature