From the Ecole de Physique des Houches Fluorescence markers for advanced microscopy
Coherent Raman imaging is a label free technique featuring chemical sensitivity that has a great potential for direct cancer cell imaging. However high-resolution, high contrast coherent Raman images have so far been restricted to table-top microscopes. In a recent publication in Light Science & Applications, High-resolution multimodal flexible coherent Raman endoscope, we bridge the microscope / endoscope gap and achieve high-resolution multimodal (CARS, SHG, 2-photon) imaging of fresh human tissue with a small flexible endoscope. Our design uses a unique combination of innovations including a double-clad hollow-core fiber with a Kagomé lattice, a microsphere focusing and a resonant miniature piezo scanner. This combination of features is dedicated to solve most of the issues raised in nonlinear endoscopy and is compatible with a broad range of multi-beam nonlinear contrasts.
Understanding the nanoscale organization of the cell membrane is a topic of high current interest. However, conventional optical microscopes fail to provide the combination of high spatial and temporal resolutions needed.
We have recently introduced optical nanoantennas to breach into these limitations and monitor nanoscale structural dynamics on biological membranes. Our latest perspective paper in J Phys Chem Letters: “Optical NanoAntenna Fluorescence Correlation Spectroscopy to Probe the Nanoscale Dynamics of Biological Membranes” aims to put into a broader context very recent works using nanophotonic techniques to probe the nanoscale organization of biological membranes.
For non-suscribers, it is also freely available on arXiv.
I have recently released a brief introduction to the key concepts for understanding the phenomenon of ﬂuorescence enhancement with optical nanostructures. This document should be a chapter of a book “Plasmonics in Chemistry and Biology” edited by Nordin Felidj and Marc Lamy de la Chapelle, Pan Stanford Editions, and is already available on arXiv. It also provides a brief review of diﬀerent approaches to enhance single molecule ﬂuorescence with plasmonic and non-plasmonic nanoantennas. Lastly, it describes three main biochemical applications opened by this technique.
This book chapter is an introduction designed for students for master degree or just starting their PhD. The main novelty is figure 2 representing the figure of merit for fluorescence enhancement as a function of the publication year for different experimental results. For more advanced readers, I recommend instead the excellent review on single photon sources with nanoantennas by Femius Koenderink.
As Pantone says: "Inventive and imaginative, Ultra Violet lights the way to what is yet to come." We couldn't agree more...