AIE-active photosensitisers for monitoring and minimising microbial contamination in the fountain solution cycle

This research project aims to develop a method for monitoring and minimising microbial contamination in the fountain solution circuit. This method is based on specially developed AIE (Aggregation Induced Emission) active photosensitisers. They fluoresce by energy transfer and emit absorbed energy to surrounding molecules when their molecular mobility (e.g. when embedded in bacteria) is photochemically stimulated (e.g. by irradiation with Vis light). This transfer to surrounding molecules leads to highly reactive oxygen species (ROS) and singlet oxygen formation. AIE-active photosensitisers are added at low concentrations (e.g., as part of the fountain solution concentrate) to monitor and deactivate microbial contamination in the fountain solution.

They are embedded in the bacteria in place and restrict their molecular mobility there. By continuously measuring the fluorescence, specially developed algorithms can be used to monitor whether microbial contamination has occurred or whether a threshold value has been exceeded. The fountain solution circuit is treated with light of a suitable wavelength (e.g., Vis LED arrays inserted into the circuit) to decontaminate as required. By stimulating the AIE-active photosensitisers present in the microorganisms, a reactive species is formed that oxidatively inactivates them (photodynamic inactivation). Successful decontamination can be demonstrated by fluorescence measurements (disappearance of the fluorescence signal).