1. Ultraviolet Nanophotonics Enables Autofluorescence Correlation Spectroscopy on Label-Free Proteins with a Single Tryptophan
- Author
-
Prithu Roy, Jean-Benoît Claude, Sunny Tiwari, Aleksandr Barulin, Jérôme Wenger, MOSAIC (MOSAIC), Institut FRESNEL (FRESNEL), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Chemical Physics (physics.chem-ph) ,[PHYS]Physics [physics] ,single molecule fluorescence ,Mechanical Engineering ,FOS: Physical sciences ,tryptophan autofluorescence ,Bioengineering ,General Chemistry ,Condensed Matter Physics ,plasmonics ,Biological Physics (physics.bio-ph) ,ultraviolet UV ,Physics - Chemical Physics ,nanophotonics ,plasmonics nanophotonics ultraviolet UV single molecule fluorescence tryptophan autofluorescence ,General Materials Science ,Physics - Biological Physics ,Optics (physics.optics) ,Physics - Optics - Abstract
International audience; Using the ultraviolet autofluorescence of tryptophan aminoacids offers fascinating perspectives to study single proteins without the drawbacks of fluorescence labelling. However, the low autofluorescence signals have so far limited the UV detection to large proteins containing several tens of tryptophan residues. This limit is not compatible with the vast majority of proteins which contain only a few tryptophans. Here we push the sensitivity of label-free ultraviolet fluorescence correlation spectroscopy (UV-FCS) down to the single tryptophan level. Our results show how the combination of nanophotonic plasmonic antennas, antioxidants and background reduction techniques can improve the signal-to-background ratio by over an order of magnitude and enable UV-FCS on thermonuclease proteins with a single tryptophan residue. This sensitivity breakthrough unlocks the applicability of UV-FCS technique to a broad library of label-free proteins.
- Published
- 2023