Extended Data Fig. 6: Entacapone photothermal signal retrieved from modulation transfer detection.
From: The Parkinson’s disease drug entacapone disrupts gut microbiome homeostasis via iron sequestration
a. 10 mM Entacapone DMSO solution (under acidic pH conditions) measured by UV-VIS spectroscopy. b. Photothermal signal time trace exhibits a π/2 phase delay relative to the intensity modulation by the AOM and instantaneous signals, such as SRS and XPM. c. Pump probe signal phase upon increasing photothermal decay time. d. Entacapone accumulation in microbiota cells via pump probe detection with delay in time and x/y channel lock-in amplifier signal detection. As photothermal is not sensitive to picosecond level delay, the y channel showed a constant strong photothermal signal from the drug, while in the x-channel, the instantaneous cross phase modulation background showed up as a cross-correlation profile of two the pump and probe laser beams.
