Characterization of a biochip for SPRI and SERS analysis of extracellular vesicles

FEMTO-ST is a research institute located in Besançon, France, affiliated with the University of Franche-Comté (UFC) and the French National Center for Scientific Research (CNRS). It houses a team of over 750 researchers and engineers working across diverse fields such as electronics, mechanics, thermal sciences, optics, and photonics, contributing to significant advancements in science and technology.

Extracellular vesicles (EVs) are nanovesicles emitted by cells. EVs are of interest both in therapeutics, as a vector for active substances, and in diagnostics. These last years, the Nano2BIO team of FEMTO-ST Institute (Besançon) had developed a multiplex biochip to characterize EVs with complementary methods (atomic force microscopy – AFM, surface plasmon resonance imaging- SPRi) [Obeid et al., 2019 ; Raizada et al., 2023]. This internship is part of an ANR project to add Raman spectroscopy to the characterization methods. This technique would give molecular information on the composition of the membrane of EVs and its content. As Raman intensity is weak, our goal is to develop a biochip that would enhance the Raman signal (surface enhanced Raman spectroscopy – SERS), while being compatible with AFM and SPRi.
The M2 internship will be carried out in cooperation with a PhD student working on the development of the biochip. A first version, enabling SERS enhancement, has already been produced. The next step is to produce a version also compatible with SPRI.

The objectives of this internship will be:
- To characterize the topography of the biochips at the nanoscopic scale using AFM, in order to guide the manufacturing process.
- Test and measure, using Raman spectroscopy, the enhancement achieved by the chip surface, with a reference molecule and EVs.
- Test the surface plasmon resonance for SPRI, with a reference sample, then EVs.

Applications are welcome from students in their 2nd year of a research master’s program or 3rd year of an engineering school. Candidates should have a sound background in physics, experience in optics or plasmonics would be a plus.