BS7.4 - Investigations of the Cellular Metabolism of Various Bacteria Utilizing Light-addressable Potentiometric Sensors (LAPS) Incorporated with Multi-chamber Structures

17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
Biosensors 7 - Cell Sensing
S. Dantism, D. Roehlen, T. Wagner, M. Schoening - Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich (Germany), P. Wagner - Department of Physics and Astronomy, Soft-Matter Physics and Biophysics Section, KU Leuven, Leuven (Belgium)
340 - 341


Light-addressable potentiometric sensors (LAPS) are field-effect-based potentiometric sensors, which are able to monitor analyte concentrations in a spatially resolved manner. Hence, a LAPS measuring system is a powerful tool to acquire a chemical image visualizing different concentrations of bio/chemical species in aqueous solutions such as for cellular metabolism studies. The planar sensor surface of LAPS allows a simple fixation of measurement chambers enabling simultaneous and multivariate analysis of different analyte solutions. In this work, 3D-printed photo-polymer-based (PPABS) multi-chamber structures were combined with LAPS to study the metabolic activity of Escherichia coli (E. coli) K12, Corynebacterium glutamicum and Lactobacillus brevis, as test microorganisms. In order to eliminate undesired influences (e.g., pH value variations of the medium and sensor signal drifts) during the measurements, differential measurements were performed to determine the acidification rates of those bacteria after glucose uptake. In order to improve the performance of the LAPS system, a novel FPGA-controlled illumination unit consisting of 16 smallsized tunable infrared laser-diode modules (LDMS) has been developed. Furthermore, a salt bridge chamber was built up and integrated with the LAPS measuring system providing multi-analyte measurements with a single Ag/AgCl reference electrode.