Wolfgang Fritzsche, head of the Nanobiophotonics department at the Leibniz Institute for Photonic Technologies Jena (Leibniz-IPHT), researches special effects on nanoparticles and how these can be used, for example, to detect pathogenic germs. For his ongoing commitment to research and teaching, the chemist has now received an adjunct professorship for physical chemistry at the Friedrich Schiller University in Jena. The certificate was presented personally by the President of the University, Walter Rosenthal.
Wolfgang Fritzsche's field of research, "Molecular Plasmonics", encompasses several interlinked scientific disciplines. On the one hand, he produces new metal nanoparticles and metallic nanostructures with precisely defined optical properties and then combines these materials with biomolecules such as DNA. “We integrate these hybrid nanostructures, for example, into the hair-thin channels of microfluidic chips and thus obtain a miniature analysis laboratory. This opens up completely new fields of application for nanostructures in biophotonics for us,” Fritzsche describes another research focus of his department. The metal nanostructures are suitable as sensitive optical markers and sensors for medical diagnostics, Here the focus is on the detection and identification of DNA molecules of pathogenic germs. "In the research projectIn the Specc , we have established an optical platform that, thanks to the DNA sensors, enables the rapid and parallel detection of sepsis-relevant fungal pathogens for the first time ,” says the chemist. Other fields of application are the analysis of food and water as well as solving environmental technology issues. As active optical antennas, the nanostructures are able to release the energy introduced as light very locally as heat or electrons. They can be used for high-precision material processing or catalysis on the nanoscale.
Wolfgang Fritzsche studied chemistry in Jena and received his doctorate in 1994 on high-resolution microscopy of DNA-protein complexes at the Max Planck Institute for Biophysical Chemistry and the Georg August University in Göttingen. After a research stay at Iowa State University in the USA, Wolfgang Fritzsche returned to Jena in 1996 and took over the management of the "Molecular Nanotechnology" working group and later the management of the "Nanobiophotonics" department at the IPHT. He is the author of over 140 peer-reviewed publications, coordinates several national and international research projects and organizes conferences on molecular plasmonics and DNA nanotechnology. He is President of the German Society for Cytometry (DGfZ) .
The Friedrich Schiller University has now honored his many years of excellent expertise in the development of nanoparticle-based methods for bioanalytics and his commitment to teaching with the title of adjunct professor.
Today, innovative tools for diagnostics and bioanalytics are needed, to be usable outside of dedicated laboratories and with less qualified personnel, at minimal costs.
Plasmonic nanostructures promise to provide sensing capabilities with the potential for ultrasensitive and robust assays in a high parallelization and miniaturization, and without the need for markers. Upon binding of molecules, the localized surface plasmon resonance (LSPR) of these structures is changed, and can be used as sensoric readout . This is possible even on a single nanostructure level, using optical darkfield detection introduced more than 100 years ago , as demonstrated for DNA detection . In contrast to SPR, LSPR senses only in a very thin layer (on the scale of the particle diameter), resulting in an efficient background suppression .
In order to multiplex this approach, an imaging spectrometer based on a Michelson interferometer has been developed, able to readout a whole array of sensors in one step . On the sensor side, microarrays of gold nanoparticle spots were fabricated using spotting of pre-synthesized gold nanoparticles . Such chemically synthesized particles allow for a cost-efficient generation of highly crystalline particles as nanosensors; by using microfluidic approaches, a higher quality and reproducibility can be achieved . Using this microarray approach, a multiplex DNA-based detection of fungal pathogens involved in sepsis could be demonstrated . DNA-based signal amplification, such as hybridization chain reaction, improves the sensitivity . Beyond DNA detection, LSPR sensing is also applicable for the detection of protein targets, such as CRP .
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