Plasmon-enhanced stimulated Raman scattering microscopy with single-molecule detection sensitivity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31754221.
- Also identified by DOI 10.1038/s41467-019-13230-1 and PMC identifier 6872561.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Stimulated Raman scattering (SRS) microscopy allows for high-speed label-free chemical imaging of biomedical systems. The imaging sensitivity of SRS microscopy is limited to ~10 mM for endogenous biomolecules. Electronic pre-resonant SRS allows detection of sub-micromolar chromophores. However, label-free SRS detection of single biomolecules having extremely small Raman cross-sections (~10<sup>-30</sup> cm<sup>2</sup> sr<sup>-1</sup>) remains unreachable. Here, we demonstrate plasmon-enhanced stimulated Raman scattering (PESRS) microscopy with single-molecule detection sensitivity. Incorporating pico-Joule laser excitation, background subtraction, and a denoising algorithm, we obtain robust single-pixel SRS spectra exhibiting single-molecule events, verified by using two isotopologues of adenine and further confirmed by digital blinking and bleaching in the temporal domain. To demonstrate the capability of PESRS for biological applications, we utilize PESRS to map adenine released from bacteria due to starvation stress. PESRS microscopy holds the promise for ultrasensitive detection and rapid mapping of molecular events in chemical and biomedical systems.
Medical subject headings
- Lasers
- Nonlinear Optical Microscopy
- Single Molecule Imaging
- Spectrum Analysis, Raman
- Staphylococcus aureus