Challenging a Preconception: Optoacoustic Spectrum Differs from the Optical Absorption Spectrum of Proteins and Dyes for Molecular Imaging
| Autor: | Yuanhui Huang, Dierk Niessing, Andriy Chmyrov, Kanuj Mishra, Christina Heichler, Juan Pablo Fuenzalida Werner, Clemens Neufert, Robert Janowski, Andre C. Stiel, Vasilis Ntziachristos, Paul Vetschera |
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| Rok vydání: | 2020 |
| Předmět: |
Models
Molecular Absorption spectroscopy Photoswitch Protein Conformation 010401 analytical chemistry 010402 general chemistry Photochemistry 01 natural sciences Fluorescence 0104 chemical sciences Analytical Chemistry Molecular Imaging Rhodamine Photoacoustic Techniques chemistry.chemical_compound Luminescent Proteins chemistry Absorption Physicochemical Limit of Detection Molecular imaging mCherry Coloring Agents Preclinical imaging Alexa Fluor |
| Zdroj: | Analytical chemistry. 92(15) |
| ISSN: | 1520-6882 |
| Popis: | Optoacoustic (photoacoustic) imaging has seen marked advances in detection and data analysis, but there is less progress in understanding the photophysics of common optoacoustic contrast agents. This gap blocks the development of novel agents and the accurate analysis and interpretation of multispectral optoacoustic images. To close it, we developed a multimodal laser spectrometer (MLS) to enable the simultaneous measurement of optoacoustic, absorbance, and fluorescence spectra. Herein, we employ MLS to analyze contrast agents (methylene blue, rhodamine 800, Alexa Fluor 750, IRDye 800CW, and indocyanine green) and proteins (sfGFP, mCherry, mKate, HcRed, iRFP720, and smURFP). We found that the optical absorption spectrum does not correlate with the optoacoustic spectrum for the majority of the analytes. We determined that for dyes, the transition underlying an aggregation state has more optoacoustic signal generation efficiency than the monomer transition. For proteins we found a favored optoacoustic relaxation that stems from the neutral or zwitterionic chromophores and unreported photoswitching behavior of tdTomato and HcRed. We then crystalized HcRed in its photoswitch optoacoustic state, confirming structurally the change in isomerization with respect to HcReds' fluorescence state. Finally, on the example of the widely used label tdTomato and the dye indocyanine green, we show the importance of correct photophysical (e.g., spectral and kinetic) information as a prerequisite for spectral-unmixing for in vivo imaging. |
| Databáze: | OpenAIRE |
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