Optical and impedimetric study of genetically modified cells for diclofenac sensing

Whole-cell biosensors, based on genetically modified yeast cells, were employed to detect anthropogenic micropollutants (e.g. drugs). Specific stimuli, e.g. traces of drugs, lead to the induction of fluorescence in the respective cells. Receptors of the cells detect specific signal molecules and induce the formation of fluorescent proteins. In this work, genetically modified cells of the yeast Saccharomyces cerevisiae BY4741 were confined in a four-chamber microfluidic cell, providing an optical monitoring of the cell behaviour and their supply with the nutrients. The measurements of the time-dependent fluorescence intensity were performed with different concentrations of the drug diclofenac, and the sensitivity of yeast cells to diclofenac was demonstrated. Cell viability was monitored by simultaneous impedance recording.