DESESBCO
Deep eutectic solvents for polymer-modified electrodes: electrochemical sensors/biosensors and corrosion protection

Challenge

Development of new modified electrode electrochemical sensors and biosensors with improved performance and better adapted for the identification and measurement of key chemical compounds in complex media and applicable in the areas of health, food and environment. The use of this modification strategy will also be followed in order to protect metals by inhibitor coatings to prevent corrosion.  

Solution

The strategic objectives of the project include the control of the nanostructure and surface morphology of the new electrochemical sensors and biosensors, with the deposition of nanomaterials and of electroactive polymers, investigating their formation in new binary and ternary deep eutectic solvents (DES). The electrochemical and electrocatalytic properties of the modified electrodes will improve the analytical parameters of the new sensors in the context of applications in the detection of important analytes in health, foods and the environment, as well as for coatings of metals that are more effective and long-lasting against corrosion.

Objectives, Activities and Results expected / achieved

The development of new electrochemical sensors and biosensors will be carried out, based on electrodes modified with polymer films prepared in deep eutectic solvents with improved analytical performance. The platforms will be tested with analytes that are important in food, health and the environment and as protective films against corrosion.
Deep eutectic solvents (DES) will play a crucial role in the project. DES are easily prepared, have low toxicity and are sufficiently conducting to act as both electrolyte and solvent, for the formation of films of electroactive polymers on appropriate electrode substrates by electropolymerization. The preparation of different polymer films in ethaline DES, principally based on phenazines, already carried out by us, demonstrated that the nanostructure, morphology and electrochemical properties of the polymer films formed are not the same. The detailed mechanism of electropolymerization in ethaline and in other binary DES are being investigated. Ternary DES, with two hydrogen bond donors, are being evaluated for the electrosynthesis of electroactive polymers, seeking lower viscosity and higher conductivity, and greater stability over time and with changes in temperature.

In parallel, the influence of incorporation of nanomaterials will be evaluated (mainly nanotubes, metal and metal oxide nanoparticles, graphene and carbon black), before, during and after electropolymerization. Electrocatalytic effects will be explored.

The electrode platforms prepared in this way will be evaluated as sensors and enzyme biosensors with model analytes. This will include using DES rather than aqueous media for the assembly of the modifier layer components, as well as different enzyme immobilization techniques. Application to key analytes for food, health and environment will then be tested, chosen in the light of current concerns and legislation.

The electropolymerisation in DES media chosen for this purpose of phenazine dyes on metals prone to corrosion will be tested and compared with the same strategy in aqueous solution.