Time-Domain Photothermal AFM Spectroscopy via Femtosecond Pulse Shaping.
Miriam Bohlmann KunzYulia PodorovaZachary T ArmstrongMartin T ZanniPublished in: Analytical chemistry (2022)
A time-domain version of photothermal microscopy using an atomic force microscope (AFM) is reported, which we call Fourier transform photothermal (FTPT) spectroscopy, where the delay between two laser pulses is varied and the Fourier transform is computed. An acousto-optic modulator-based pulse shaper sets the delay and phases of the pulses shot-to-shot at 100 kHz, enabling background subtraction and data collection in the rotating frame. The pulse shaper is also used to flatten the pulse spectrum, thereby eliminating the need for normalization by the laser spectrum. We demonstrate the method on 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn) microcrystals and Mn-phthalocyanine islands, confirming subdiffraction spatial resolution, and providing new spectroscopic insights likely linked to structural defects in the crystals.
Keyphrases
- single molecule
- photodynamic therapy
- high speed
- blood pressure
- atomic force microscopy
- high resolution
- cancer therapy
- drug delivery
- drug release
- optical coherence tomography
- high frequency
- molecular docking
- room temperature
- electronic health record
- magnetic resonance imaging
- ionic liquid
- solid state
- mass spectrometry
- machine learning
- diffusion weighted imaging
- transition metal