Label-free imaging of fibroblast membrane interfaces and protein signatures with vibrational infrared photothermal and phase signals
Abstract
Label-free vibrational imaging of biological samples has attracted significant interest due to its integration of structural and chemical information. Vibrational infrared photothermal amplitude and phase signal (VIPPS) imaging provide label-free chemical identification by targeting the characteristic resonances of biological compounds that are present in the mid-infrared fingerprint region (3 µm - 12 µm). High contrast imaging of subcellular features and chemical identification of protein secondary structures in unlabeled and labeled fibroblast cells embedded in a collagen-rich extracellular matrix is demonstrated by combining contrast from absorption signatures (amplitude signals) with sensitive detection of different heat properties (lock-in phase signals). We present that the detectability of nano-sized cell membranes is enhanced to well below the optical diffraction limit since the membranes are found to act as thermal barriers. VIPPS offers a novel combination of chemical imaging and thermal diffusion characterization that paves the way towards label-free imaging of cell models and tissues as well as the study of intracellular heat dynamics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 14, 2020
- Source ID
- 10.1364/boe.411888
Entities
People
- Allyson E. Sgro
- Breanna M. O’reilly
- Daniel Langley
- Geva Hilzenrat
- Michelle Y Sander
- Panagis D. Samolis
- Sally L. McArthur
- Shyamsunder Erramilli
- Zay Oo
Organizations
- Air Force Office of Scientific Research
- Australian National Fabrication Facility
- Boston University
- Burroughs Wellcome Fund
- National Institutes of Health
- National Science Foundation