Nanoscale mapping of newly-synthesised phospholipid molecules in a biological cell using tip-enhanced Raman spectroscopy

Abstract

Nanoscale chemical mapping of newly-synthesised phospholipid molecules inside a mammalian cell is demonstrated using tip-enhanced Raman spectroscopy (TERS) for the first time using mouse pre-adipocyte cells as a model system. Newly-synthesised membrane phospholipid distribution within a pre-adipocyte cell is mapped with <20 nm spatial resolution, overcoming the diffraction limit of confocal Raman spectroscopy via plasmonic enhancement of Raman signals at a TERS tip-apex.

Tip‐Enhanced Raman Spectroscopy: A Tool for Nanoscale Chemical and Structural Characterization of Biomolecules

“…Similar TERS features associated with lipid structures were observed in mitochondria, bacteria, and human/animal cells . The Gram‐positive bacteria Staphylococcus epidermidis presented TERS signatures that revealed their protein (mostly Phe, Tyr, and amide bands), sugar, and lipid components .…”

Atomic Force Microscopy Meets Biophysics, Bioengineering, Chemistry, and Materials Science

“…[44] Therefore, the combination of AFM (which can be operated in liquid conditions) with Raman spectroscopy can be usefult oi nvestigate both topographical and chemicalc hanges at the nanoscale for aw ide range of (biological) samples, such as fibril proteins, [45] carbon nanotubes, [46] DNA, [47] and cells. [48] More specifically,t ip-enhanced Ramans pectroscopy (TERS) [49] uses an apertureless probe to enhancet he Raman signal emitted by the sample molecules, which are separated from the probe by af ew nanometers, and am etallict ip that is irradiated along its apical axis by al aser with aw avelength in the visible region (l = 500-650 nm). Because the tip is sufficiently close to the sample, field enhancement is possible, leadingt om olecular excitation and registration of local Ramans pectra.…”

Recent advances in hybrid measurement methods based on atomic force microscopy and surface sensitive measurement techniques

“…gemstone identication), 227 biology (e.g. secondary structure of polypeptides/proteins, phospholipids), [228][229][230][231] material science 232,233 (e.g. semiconductors, carbon materials and polymers) and life science (e.g.…”

“…The resolution of TERS is typically in the order of 20 nm (see Fig. 9), 231,237,238 but can be enhanced by specic reection modes up to 1 nm. 239 TERS has been utilized in a broad range of applications in biology, such as pathogens, 241 cell membranes 242 and peptides, 243 in materials science, 244 such as polymer blends, and chemical engineering, i.e.…”