Photothermal Microscopy and
Spectroscopy Webinar

Mid-infrared photothermal (MIP) microscopy allows fast, label-free chemical imaging with high spatial resolution. To enhance signal contrast in applications involving complex matrices, such as cell imaging, it may be beneficial to detect biomolecules via vibrational probes absorbing in the cell-silent spectral region. Promising vibrational probes for selective imaging of lipids and proteins in cells are the alkyne and azide functional groups, and deuterium. A widefield heterodyne MIP system based on an external-cavity quantum cascade laser emitting around 2100 cm ¹ is presented together with suitable detection schemes. Results from imaging of alkyne-tagged palmitic acid (PA), azide-tagged PA and perdeuterated PA are discussed.