Further development of fluorescence excitation spectroscopy

|   Physik, Chemie, Gäste

Matthias Rang & Peter Stolz

In Goethean science there is a distinction between organic and inorganic science which goes back to Goethe and was described by Steiner in his "Grundlinien einer Erkenntnistheorie der Goetheschen Weltanschauung". In each field of research, multiple disciplines are connected with each other (such as physics, chemistry and geology in inorganic science or biology, botany, morphology, etc. in organic natural science), but it is rather rare for a research question to be located in between, such that the two fields of research of animate and inanimate nature are equally connected. Such a research question is present in the current project, which, in a very general description, deals with the relationship between light and life.

Inspired by the work of biophysicist Fritz Popp, Jürgen Strube developed fluorescence excitation spectroscopy some twenty-five years ago. Biological samples - particularly food - were illuminated with different coloured light. Strube's research found that the biological samples glowed back very lightly in the dark, with varying intensity and different colours. Since then, fluorescence excitation spectroscopy has been further developed by Strube and Stolz at the Kwalis Research Institute near Fulda (DE). In particular, the institute has been able to show the difference in the quality of food products from organic, biodynamic and conventional cultivation. It can be examined whether, for example, an apple is ripe or it is still in a vegetative growth stage.

In this project, which is a cooperation between the Research Institute Kwalis GmbH and the Natural Science Section, we want to continue this research. Our first and primary goal is to set up a second measuring system. More than 100,000 series of measurements have been carried out at the existing facility at Kwalis, which is now over twenty years old. We therefore consider the completion of a new facility to be urgent. This will allow us to carry out comparative measurements with the existing facility and thus to characterise the method itself even more precisely.

Following a preliminary phase, we were finally able to start the research project in May 2019 and are currently in the middle of developing the new facility. The measurement of the light emission of the biological samples represents a challenge, since the intensity (even for today's conditions in modern quantum-optical laboratories) is extremely low and the equipment must be sensitive to individual light quanta. Additionally, the associated amplifier and counter electronics have cost us a lot of time over the past year and development is still ongoing. Technical challenges also arise from the fact that the detectors for noise suppression have to be strongly cooled while at the same time positioned close to the sample in order not to lose light intensity. As a result, the measuring head of the system is very crowded and the dimensioning of the individual components requires a lot of attention and time. Nevertheless, we hope to be able to complete the facility in 2020 and then move on to the further objectives of the project, which is scheduled to last three years in total.

The project is financially supported by the Software AG Foundation, the Wolfgang Gutberlet Foundation, the Rudolf Steiner Fund for Scientific Research Nuremberg, and the Eudoxos Foundation. We are very grateful for the support and sponsorship of these institutions.