Towards the development of an automated ATP measuring platform to monitor microbial quality of drinking water

This work aimed to develop an automated and nearly on-line method to monitor ATP levels in drinking water as an indicator of microbial contamination. The system consists of a microfluidic cartridge installed in a light tight box, where the sample is mixed with the reagents and the emitted light is detected by a photomultiplier.

Temperature in the assay box is controlled and set to 25°C. Calibration of the system using ATP standard solutions was successful, both for free and for total ATP. Chemical release of ATP by reagent addition however resulted in the formation of particles that ultimately clogged the microfluidic channels.

An alternative thermal lysis step was implemented, by adding a flow-though heating/cooling step to the system. Thermal lysis showed efficient release of ATP from an E. coli dilution, but the releasing efficiency varied according to the type of water. Overall, the developed prototype system proves the concept of a lab-on-a-chip ATP analyzer.