We are thrilled to announce the arrival of our newest PhD student, Malavika Kayyil Veedu, who will be joining us for the next three years. She will be working with us on a cutting-edge research project on plasmonics-enhanced fluorescence and nanopores.
Malavika comes to us as part of the Marie Curie research program doctoral network called Dynamo, funded by the European Union. With her background and experience, she will be a valuable addition to our team and we can't wait to see the exciting results that come from her research.
We believe that collaboration is key to making meaningful advancements in our field, and we are confident that Malavika will bring a fresh perspective and new ideas to our lab.
Ultraviolet Nanophotonics Enables Autofluorescence Correlation Spectroscopy on Label-Free Proteins With a Single Tryptophan
Proteins are naturally fluorescent in the ultraviolet, offering an appealing approach to probe proteins in their native state without introducing any external fluorescent label. The UV autofluorescence of proteins is based on the presence of tryptophan amino acids, which typically occur as 1 to 5 tryptophan per protein. However, due to weak signals and large backgrounds in the UV, the current technology was restricted to large proteins featuring several tens of tryptophan residues. The vast majority of proteins remained well below the detection sensitivity for single label-free protein detection.
In a recent Nano Letters publication, our team breaks into this sensitivity limit and achieves label-free UV-autofluorescence detection down to the single tryptophan level thanks to a nanophotonic enhancement of the signal. Our approach relies on a rationally-designed combination of plasmonic antennas, antioxidants and background noise reduction techniques to improve the signal to background ratio by over an order of magnitude. Achieving the ultimate sensitivity of UV-FCS down to the single tryptophan regime has wide applications for various communities from nanophotonics to biochemistry.
We conclusively demonstrate UV-fluorescence correlation spectroscopy (UV-FCS) on proteins with a single tryptophan residue. This unlocks the applicability of UV-FCS to a broad library of thousands of proteins, which remained previously inaccessible (over 90% of human proteins have at least one tryptophan residue, but only 4% have more than 20 tryptophans). Fluorescence correlation spectroscopy (FCS) and related techniques have a large impact on molecular biophysics in assessing diffusion properties, local concentrations or kinetic reaction rates.
The signal to background maximization approach is of interest to a wide range of scientists and engineers working with single molecule fluorescence, photonics, or plasmonics. Our article details several multidisciplinary aspects: (i) plasmonic nanophotonic elements to enhance the fluorescence, (ii) antioxidants to neutralize the reactive oxygen species ubiquitous to ultraviolet and (iii) background suppression based on a rational understanding of the background physical origins.
Preprint is also freely availabe on ArXiv 2301.01516
We currently have two open positions with funding from China Scholarship Council CSC and Groupe Ecoles Centrales GEC-CSC:
- One for a PhD: "UV autofluorescence microscopy"
- One for a postdoc: "Fiber-integrated plasmonic nanotweezers to manipulate single proteins"
Find them on the https://gec-csc.fr/ website with application form, section Natural & Life sciences: Physics & Astronomy. Application deadline January 10 2023!
It is not mentioned on the application website but I would expect Chinese nationality is a requirement for eligibility.
We're hiring! PhD fellowship on dynamic control in hybrid plasmonic nanopores: road to next generation multiplexed single molecule detection
Within the Marie Skłodowska-Curie Doctoral Networks DYNAMO merging of 6 world-leading academic groups and 1 high tech company, we are offering one full PhD fellowship on plasmonic trapping and enhanced UV label-free single protein detection with plasmonic nanopores.
See the complete details in the description enclosed below. The application website is here.
You may also find it on Academic Positions
• Regular submission deadline: September 6, 2022
• Regular registration deadline: October 4, 2022
• Conference: Oct 25-27, 2022