A mobile biosensor using living cells for water quality analysis

Cell based biosensor systems using miniaturized electrochemical or optical sensors have been introduced in different applications such as pharmacology or as an alternative for animal experiments in toxicology [1-3]. Combining such systems with mobile phones they can be used in wireless networks for applications in area-wide environmental monitoring, homeland security or for Point-of-Care technologies [4]. For these applications the biosensor devices have to be operated automatically and autonomous. I.e. the biosensor devices have to be embedded into a software controlled systems which takes care of configuration, data processing and interpretation. Also aspects as maintenance and quality assurance have to be considered. In this work a mobile handheld biosensor system is described. It is intended for use in environmental monitoring scenarios. The focus is put on water quality analysis and to provide evidence of different toxins (e.g. herbicides or hormones) when taking probes from the outlet of a sewage treatment plant. The enabling technology towards cell based biomonitoring with living cells as signal converters is to use a multiparametric electrochemical biochip. The sensor chip monitors the metabolism and morphology of the cells via miniaturized pH, dissolved oxygen and impedance sensors. This BioChip-C is processed in thin film technology on a ceramic substrate. For measurement of the cellular respiration an amperometric dissolved oxygen sensor is used, for measurement of extracellular acidification a RuOx metal oxide pH sensor is implemented and for measurement of the morphology of the cells an interdigitated electrode structure is used. The paper shows that it is possible to establish a meshed network by installing multiparametric biosensor devices which are linked wirelessly to a central database system that provides an end user experiment analysis service.