Recently, a research team led by Professor Yang Liangbao from Institute of Health and Medical Technology of the Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences (CAS) has successfully utilized surface-enhanced Raman spectroscopy (SERS) to accurately monitor the diffusion behavior of a single molecule in sub-nanometer space.
The research was published in The Journal of Physical Chemistry Letters.
SERS technology, a highly sensitive and selective analytical technique, enables single-molecule level analysis by triggering a resonance phenomenon on a metal surface that significantly enhances the molecular Raman signal. However, long-term monitoring of unlabeled individual molecules remains a challenge.
In this study, the team utilized the excellent photothermal effect of gold nanorods to construct hotspot structures with a gap size of ~ 1.0 nm using laser reconstruction.
The constructed hotspot not only provided superb SERS enhancement but also actively captured the target molecules, realizing real-time monitoring and analysis of the diffusion behavior of crystalline violet single molecules.
"This allowed us to observe the blinking behavior of single crystal violet (CV) molecules for durations of up to 4 minutes using dynamic surface-enhanced Raman spectroscopy (D-SERS)," said YAN Wuwen, member of team.
Combining density-functional theory (DFT) calculations and SERS-mapping results, they concluded that the crystalline violet single molecules can be confined in sub-nanometer space.
"This allowed us to observe the blinking behavior of single crystal violet (CV) molecules for durations of up to 4 minutes using dynamic surface-enhanced Raman spectroscopy (D-SERS)," said YAN Wuwen, member of team.
This research provides a unique way to understand molecular interactions, chemical reactions, and the behavior of biomolecules.
Figure Left: Transmission electron micrograph of the cross-section of laser reconfigured gold nanorods; Middle: results of the detection and analysis of single-molecule diffusion behavior; Right: results of SERS-mapping of crystalline violet molecules in 4 min. (Image by YAN Wuwen)
