Beyond Color: Hybrid Vibrational-Electronic Broadband Coherent Anti-Stokes Raman Scattering for Molecularly Informed...

We demonstrate that broadband coherent anti-Stokes Raman scattering (BCARS) on hematoxylin and eosin (H&E)-stained tissue generates a hybrid vibrational-electronic spectroscopic contrast arising from coupled Raman-active vibrations and chromatin-hematoxylin electronic resonances. This hybrid response, inaccessible to conventional spontaneous Raman or infrared microscopy due to fluorescence and substrate interference, transforms routine histology slides into sources of quantitative molecular information. The resulting spectra encode both Raman-active vibrations and resonance-modulated four-wave-mixing contributions arising from hemalum-chromatin interactions, thereby linking histological color contrast to quantitative, machine-readable spectral features. In breast tissue microarrays, we show (i) pixel-wise wavenumber-shift mapping that resolves subnuclear domains and highlights necrosis-associated nuclear shrinkage; (ii) phase-retrieved Raman-like spectra that separate hemalum-associated resonant features from nonpigmented contributions attributable to processing reagents; and (iii) nucleus-level discrimination of ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), and invasive lobular carcinoma (ILC) using a PCA-LDA workflow. This study is a feasibility demonstration rather than a clinical validation, but establishes electronically enhanced BCARS on routine H&E slides as a route to unlock archival repositories for molecular phenotyping and AI-enabled histopathology.