AI Article Synopsis
- The study investigates new nanojunctions made from gold and silicon particles for enhanced surface measurements in coherent anti-Stokes Raman spectroscopy (CARS).
- By successfully reducing background noise, they achieved detectable molecular signals using lower power densities than previously reported.
- This approach shows promise for improved sensing technologies by avoiding issues seen in traditional all-metal systems.
Article Abstract
We discuss an experimental configuration consisting of {Au film}-molecule-{Au particle} or {Au film}-molecule-{Si particle} nanojunctions for performing wide-field surface-enhanced CARS (SE-CARS) measurements in a reproducible and controllable manner. While the allowable illumination dosage in the {Au film}-molecule-{Au particle} case is limited by the strong two-photon background from the gold, we successfully generate a detectable coherent Raman response from a molecular monolayer using the lowest reported average power densities to-date. With a vision to minimize the two-photon background and the intrinsic losses observed in all-metal plasmonic systems, we examine the possibility of using high-index dielectric particles on top of a thin metal film to generate strong nanoscopic hotspots. We demonstrate repeatable SE-CARS measurements at the {Au film}-molecule-{Si particle} heterojunction, underlining the usability of this experimental geometry. This work paves the way for the development of next-generation of chemical and biomolecular sensing assays that can minimize some of the major drawbacks encountered in fragile and lossy all-metal plasmonic systems.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11382608 | PMC |
| http://dx.doi.org/10.1021/acs.jpcc.2c01642 | DOI Listing |
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