Wide-Field Surface-Enhanced Coherent Anti-Stokes Raman Scattering Microscopy

Abstract

Surface-enhanced Raman scattering (SERS) spectroscopy has been used extensively to study biology, chemistry, and materials. However, point-by-point SERS mapping is time-consuming, taking minutes to hours for large-scale imaging. Here, we report a wide-field surface-enhanced coherent anti-Stokes Raman scattering (WISE-CARS) microscope for monitoring nanotags in live cells and labelfree detection of metabolic molecules. The WISE-CARS microscope achieves an imaging speed of 120 fps for a field of view of 130 μm × 130 μm. By spectral focusing of femtosecond lasers, a hyperspectral WISE-CARS stack of 60 frames can be acquired within 0.5 s, where over 1 million Raman spectra are parallelly recorded with a spectral resolution of 10 cm −1 . As applications, we demonstrate time-lapse, three-dimensional (3D) WISE-CARS imaging of nanotags in live cells as well as label-free detection of adenine released from S. aureus.

Computational coherent Raman scattering imaging: breaking physical barriers by fusion of advanced instrumentation and data science

“…Plasmonic enhancement with nanostructures has been reported on both CARS [44] and SRS [45] with single-molecule sensitivity. With minimal requirement on laser powers, plasmonic CARS could be implemented with a wide-field configuration [46]. This opens doors to imaging at unprecedented speeds if combined with stateof-the-art high-speed cameras.…”

Broadband Four‐Wave Mixing Enhanced by Plasmonic Surface Lattice Resonance and Localized Surface Plasmon Resonance in an Azimuthally Chirped Grating

“…[ 1 ] Four‐wave mixing (FWM) is a third‐order nonlinear optical process. Its intriguing properties can be harnessed to manifest applications in biosensing, [ 2 ] nonlinear microscopy and imaging, [ 3 ] telecommunications, [ 4 ] all‐optical switching, [ 5 ] signal regeneration, [ 6 ] phase‐sensitive amplification, [ 7 ] entangled photon pair generation, [ 8 ] and metrology. [ 9 ] Enhancement of nonlinear light–matter interaction by carefully tailoring the geometry of nanometer‐scale cavities is a very effective way to amplify these processes.…”

Surface-Enhanced Coherent Anti-Stokes Raman Scattering of Molecules near Metal–Dielectric Nanojunctions

“…Surface-enhanced CRS was first demonstrated in the form of surface-enhanced CARS (SE-CARS) in 1979 by using the propagating surface plasmon polariton (SPP) modes supported on a flat silver film to amplify the CARS spectrum of liquid benzene . Subsequent work has focused predominantly on plasmonic junctions in gold and silver nanostructures, confirming the ability of plasmonic resonances to amplify the CRS signal, even reaching the single-molecule limit. ,− These metallic systems are chosen as they feature some of the highest achievable field-enhancement factors. However, there is a limit to how much incident radiation can be applied before photoinduced breakdown of the plasmonic substrate and the molecule occurs. − It has been shown that under ultrafast excitation the electron temperature can reach thousands of kelvin and that also the lattice temperature can go up, affecting the structural integrity of the junction.…”