Ultrasensitive Vibrational Imaging of Retinoids by Visible Preresonance Stimulated Raman Scattering Microscopy.
Minghua ZhugeKai-Chih HuangHyeon Jeong LeeYing JiangYuying TanHaonan LinPu-Ting DongGuangyuan ZhaoDaniela MateiQing YangJi-Xin ChengPublished in: Advanced science (Weinheim, Baden-Wurttemberg, Germany) (2021)
High-sensitivity chemical imaging offers a window to decipher the molecular orchestra inside a living system. Based on vibrational fingerprint signatures, coherent Raman scattering microscopy provides a label-free approach to map biomolecules and drug molecules inside a cell. Yet, by near-infrared (NIR) pulse excitation, the sensitivity is limited to millimolar concentration for endogenous biomolecules. Here, the imaging sensitivity of stimulated Raman scattering (SRS) is significantly boosted for retinoid molecules to 34 micromolar via electronic preresonance in the visible wavelength regime. Retinoids play critical roles in development, immunity, stem cell differentiation, and lipid metabolism. By visible preresonance SRS (VP-SRS) imaging, retinoid distribution in single embryonic neurons and mouse brain tissues is mapped, retinoid storage in chemoresistant pancreatic and ovarian cancers is revealed, and retinoids stored in protein network and lipid droplets of Caenorahbditis elegans are identified. These results demonstrate VP-SRS microscopy as an ultrasensitive label-free chemical imaging tool and collectively open new opportunities of understanding the function of retinoids in biological systems.
Keyphrases
- label free
- high resolution
- blood pressure
- mass spectrometry
- drug delivery
- optical coherence tomography
- high speed
- gold nanoparticles
- stem cells
- density functional theory
- fluorescence imaging
- bone marrow
- spinal cord injury
- photodynamic therapy
- molecular dynamics simulations
- gene expression
- high throughput
- emergency department
- room temperature
- energy transfer
- mesenchymal stem cells
- tandem mass spectrometry
- protein protein