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 label-free 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.