WP6. Prototyping of a tailored Biosensor & Catalyst

D.6.1 First evidence of the optimisation of a tailored (electro)catalyst
D.6.2 First evidence of the optimisation of a tailored CME-based microfluidic biosensor.
D.6.3 First demonstrator of a metallic tailored fuel-cell (electro)catalyst
D.6.4 First demonstrator of a tailored microfluidic CME-based biosensor



“Copper Metallization of Gold Nanostructure Activated Polypyrrole by Electroless Deposition" Electrochimica Acta (https://doi.org/10.1016/j.electacta.2017.06.157)



Thiocholine (TCh) is the enzymatic product obtained from the interaction of the Acetylcholinesterase enzyme (AChE) and its specific substrate Acetylthiocholine Chloride (ACTh Cl). AChE is the main enzyme of which activity is inhibited irreversibly by pesticides containing organophosphorus (OP) compounds. TCh is an electroactive species and it is used for electrochemical detection of pesticides.

Nanostructured zirconia has both the role of an enhancer for the electron transfer rate as well as a platform for immobilizing the AChE enzyme. Electrochemical methods are the most commonly used detection methods for OPs.  Cyclic Voltammetry (CV) method is used to determine the oxidation potential of TCh in order to be applied in an amperometric detection system for portable biosensors with applications in environmental pollution control.

For the amperometric detection of TCh an electron beam evaporated gold transducer was modified with a thin film of NS-ZrO2 produced with the supersonic cluster beam deposition  technique. The fixed potential applied during the assessment was the oxidation potential of TCh obtained through voltammetric methods. Concentrations of synthetically produced TCh ranging between 5 uM and 25 uM were added to a Phosphate Buffer Solution (PBS) under continuous stirring and the obtained current level for each concentration was registered, in a determined period of time. In the end the concentrations used were plotted against the current peaks for each concentration and the limit of detection (LOD) of the system was determined.  For this example in particular, the LOD obtained was of 0.25 uM while the Bare Au control transducer has expressed a LOD of 0.3 uM.  NS-ZrO2 modified transducers  have shown to improve in the electrochemical behavior in terms of electron transfer and electrochemical detection capability, therefore making them a promising platform that can be integrated in electrochemical biosensing devices for environmental pollution monitoring.



The proposed integrated microfluidics biosensors device was produced by integrating the three electrodes(Au working, Ag/AgCl quasi-reference electrode and Pt-counter electrode) fabricated by supersonic cluster beam implantation into microfluidics platform fabricated by fused deposition modeling 3D printer.

After the required three electrodes were successfully produced on ABS base material and the microfluidics fabrication protocol with electrode integration steps were realized,  the three electrodes were integrated without any breaks.

To perform electrochemical test the device should be connected to a potentiostat with connection pad. However, connecting very hard electrical connectors like crocodile clip can easily break the connection pad  when directly connected to it. Therefore, we used highly conductive metallized papers interconnectors fabricated by deposition of Au thin films using supersonic cluster beam deposition. Then, the metallized papers were connected. The prototype device holder is also  fabricated using FDM.

Finally, the prototype device will be electrochemically characterized and then customized to detect organophosphate pesticide.