Regioselective Tip-Enhanced Raman Spectroscopy of Lipid Membranes with Sub-Nanometer Axial Resolution

• DOI: 10.1021/acs.nanolett.3c00689
• Publication Date: 2023-04-25T10:56:15Z
• Authors: Dušan Mrđenović; Zi-Xi Tang; Yashashwa Pandey; Weitao Su; Yao Zhang; Naresh Kumar; Renato Zenobi
• Keywords: Dipalmitoylphosphatidylcholine

Noninvasive and label-free analysis of cell membranes at the nanoscale is essential to comprehend vital cellular processes. However, conventional analytical tools generally fail meet this challenge due lack required sensitivity and/or spatial resolution. Herein, we demonstrate that tip-enhanced Raman spectroscopy (TERS) a powerful nanoanalytical tool analyze dipalmitoylphosphatidylcholine (DPPC) bilayers human with submolecular resolution in vertical direction. Unlike far-field measurements, TERS spectra DPPC reproducibly exhibited uniquely shaped C-H band. These unique spectral features were also observed spectrum pancreatic cancer cells. Spectral deconvolution DFT simulations confirmed signal primarily originated from vibrations CH3 groups choline headgroup lipids. The reproducible results obtained study unequivocally ultrahigh for nanoanalysis lipid under ambient conditions.