In this PhD project, yeasts Saccharomyces cerevisiae will be investigated by two important methods: electrochemical and mechanical after exposure with toxic materials and electric field. Electrochemical methods will be used to determine cells viability and cell wall permeability. Cells physical properties will be evaluated by mechanical dynamical characteristics, such as resonant frequency, stiffness and friction. These characteristics are very important in cell damage diagnosis. Interdisciplinary researches combining mechanics and biochemistry can give additional information about cells healthy and diseases. As powerful method in single cell researches two methods will be used for experimental research: SECM and AFM. Both of them can work in the cell’s natural environment, and evaluate single cells locally. Since SECM is equipped with ultramicroelectrode, it will be possible to detect the effect of low concentrations toxic materials. Additionally, SECM will be applied in order to exposure the cells by electric field and register changes in cell viability immediately. To evaluate damage to the cell, the mathematical model will be created, which describes single cell and determine toxic materials and electric field influence on cells mechanical properties. The relation between cells biochemical and mechanical properties will allow to extend the knowledge about living cells, additionally, it is expected to create simple and fast methodology to determine cells viability.
Yeast investigations by a Scanning Electrochemical Microscope (SECM) is a relatively new field of science: despite of the fact, that there are many studies in the world where the yeasts are measured by electrochemical methods, SECM studies are used rarely. Research on the mechanical properties of cells is performed using atomic force microscope (AFM) and mathematical models. Initial research on the modeling and mechanical properties of yeast cells has been performed in our laboratory. The results show that the electrochemical activity of yeast cells is related to their mechanical properties.