Infrared-spectroscopic, dynamic near-field microscopy of living cells and nanoparticles in water
Autor: | Thorsten Gölz, Enrico Bau, Fritz Keilmann, Korbinian J. Kaltenecker |
---|---|
Rok vydání: | 2021 |
Předmět: |
Intravital Microscopy
Optical Phenomena Infrared Science Infrared spectroscopy Molecular imaging Article law.invention Scanning probe microscopy Optical microscope law Spectroscopy Fourier Transform Infrared Escherichia coli Humans Nanotechnology Super-resolution microscopy Absorption (electromagnetic radiation) Cellular microbiology Microscopy Multidisciplinary Spectroscopy Near-Infrared Resolution (electron density) Silicon Compounds Water Chemical physics A549 Cells Medicine Nanoparticles Near-field scanning optical microscope Single-Cell Analysis |
Zdroj: | Scientific Reports Scientific Reports, Vol 11, Iss 1, Pp 1-12 (2021) |
ISSN: | 2045-2322 |
Popis: | Infrared fingerprint spectra can reveal the chemical nature of materials down to 20-nm detail, far below the diffraction limit, when probed by scattering-type scanning near-field optical microscopy (s-SNOM). But this was impossible with living cells or aqueous processes as in corrosion, due to water-related absorption and tip contamination. Here, we demonstrate infrared s-SNOM of water-suspended objects by probing them through a 10-nm thick SiN membrane. This separator stretches freely over up to 250 µm, providing an upper, stable surface to the scanning tip, while its lower surface is in contact with the liquid and localises adhering objects. We present its proof-of-principle applicability in biology by observing simply drop-casted, living E. coli in nutrient medium, as well as living A549 cancer cells, as they divide, move and develop rich sub-cellular morphology and adhesion patterns, at 150 nm resolution. Their infrared spectra reveal the local abundances of water, proteins, and lipids within a depth of ca. 100 nm below the SiN membrane, as we verify by analysing well-defined, suspended polymer spheres and through model calculations. SiN-membrane based s-SNOM thus establishes a novel tool of live cell nano-imaging that returns structure, dynamics and chemical composition. This method should benefit the nanoscale analysis of any aqueous system, from physics to medicine. |
Databáze: | OpenAIRE |
Externí odkaz: |