Biosensor development for the characterization of exosomes as biomarkers using surface-enhanced Raman scattering (ExoSurf)
The ExoSurf project is funded by the Ministry of Science, Research and Culture of the State of Brandenburg within the StaF program in Germany.
Biomarkers are increasingly used for the early detection of diseases such as cancer and heart attacks. The majority of these are substances from blood or urine, the quantitative detection of which enables an objective assessment of the disease process. This applies to both laboratory diagnostics and point-of-care analysis, which is becoming increasingly important, especially in rural areas of Brandenburg. In recent years, the importance of exosomes for the early detection of cancer has been recognized in particular. For the detection and characterization of exosomes, Raman spectroscopy will be used, which as a method established in chemistry is also increasingly applied in biomedicine. The low intensity of the Raman signal is usually problematic, but here it will be sufficiently amplified by plasmonic effects, specifically surface amplification on nanometer-sized metal structures.
Surface-enhanced Raman spectroscopy (SERS) is considered an effective technique for obtaining an optical fingerprint of a few molecules in the micrometer or even nm range. Using SERS, the hurdle of low Raman scattering rates is overcome by exploiting the tremendous local enhancement of the incident electromagnetic field obtained by electromagnetic coupling between nanoparticles placed in close proximity to the analytes.
The mission of this project is to "go beyond silver and gold" to develop high-performance and low-cost substrates based entirely on CMOS-compatible microfabrication processes that explore novel plasmonic materials and theoretically open a space for describing their optical properties. Indeed, a proper evaluation of the SERS mechanism and an optimized design of the plasmonic structures require a detailed analysis of the electromagnetic field interaction with suitably patterned plasmonic material.
Fraunhofer Institute for Cell Therapy and Immunology, Department of Bioanalytics and Bioprocesses, Potsdam-Golm