Project-ID: SC15-004
Project start: 01. Mai 2017
Project end: will follow
Runtime: 24 months / finished
Funding amount: € 199.800,00

Brief summary:

The pollution of water with specific hazardous substances and their quantification is a key issue in water management and of great importance. Based on this the main aim of our project is the development and optimization ion selective electrodes (ISEs) for rapid and accurate water analysis. This goal includes the development of a suitable potentiometric ISE prototype which will bear a cosane-analyte complex and will be able to detect pollutants down to a concentration of 10-6 mol/L within the first and to 10-9 mol/L within the final project stage.

The therefore necessary complexes will be synthesized via the conjugation with the protonated form of a desired analyte. Since this possibility is so far only working for nitrogen containing analytes, we will use a set of 10 organic water contaminants mainly belonging to the group of pharmaceutical active ingredients (PhACs) for the synthesis of the corresponding complexes. These compounds were chosen based on their recent detection within the Danube and all water and air stable complexes will be included in the first prototype electrodes.

These electrodes will incorporate membranes of the ion pair complex and plasticized PVC. In order to find the best composition ( regarding sensitivity, selectivity and nernstian behaviour), screenings with different plasticizers and different ratios of plasticizer, PVC and the ion pair complexes will be carried out. The best working potentiometric ISE electrodes will afterwards be tested in spiked samples with different turbidity levels, sediments and microbial contamination in order to establish a protocol for real life samples and the improved sensor.

Starting parallel to the sensor evaluation we will focus on the improvement of the sensitivity in order to reach contamination levels down to 10-9 mol/L. This will include the sensor miniaturization using commercial electrodes (screen printed electrodes, thin film electrodes) or graphene based field effect transistors (FETs) as an alternative. These devices will be combined with our complexes in order to improve the sensitivity. Since it might be very challenging to find a working setup for these low concentrations, a solid phase extraction (SPE) step for 1000fold analyte enrichment will be developed and used as backup to reach our target. As last step, our developed final device will be used for the quantification of pollutions in water samples from the Danube. In addition the possibility of direct stream water measurements will be investigated.

This project is expected to lead to the development of an approach towards the preparation of ion sensitive devices for all kind of nitrogen containing water and environment pollutants. If successful this will enable us to prepare taylor-made electrodes/sensors for all kind of applications within a minimal amount of time. Such sensors would be a perfect tool for the monitoring of contamination spreading through water systems without any delay compared with LCMS methods.

Keywords:
Limnology, water safety, biosensors, analytical chemistry