nir-vana innovation network

The Ukrainian University since 2000 works on the method of modification of planar printed electrodes with metal and metal oxides particles for the using as sensitive elements of chemical/biochemical sensors. It develops methods of environmental, food, pharmaceutical, and biomedical analysis, and is working on sensitive elements for voltammetric chemical and biosensors. The University develops methods of modification of 3D and planar screen printed electrodes with silica thin films using sol- gel technique. The silica film obtained onto the surface of the electrodes is mesoporous and electroconductive. The incorporation of the nanostructured metal or metal oxide particles within mesoporous silica film onto the surface of the electrodes is a promising way to obtain sensitive elements of chemical/biochemical sensors.
The modification of the electrodes by metal (Au, Pt) or metal oxide (CuO, MnO2, Fe2O3) nanoparticles is fulfilled in two ways:
1. Electrodeposition of the metal or metal oxide nanoparticles from the aqueous solution. The fixation of the particles onto the surface of the electrode by silica thin film
2. The one-step modification of the electrode by silica film with encapsulated metal or metal oxide particles.
The methods of microscopy (AFM, SEM, TEM) confirmed the formation of uniformly distributed nanostructured metal/metal oxide particles on the surface (the average diameter of the particles is 100 – 250 nm). The silica film fixes particles on the surface and thus increased the operation stability of the electrodes.
The developed electrodes demonstrated enhanced electroactive surface area compare to non modified one and electrocatalytic activity in the presence of hydrogen peroxide especially those modified with Pt, and metal oxide nanopartilces. The limit of detection of H2O2 is around 10 mkM. The reproducibility of the analytical response of 1.10-4 M of H2O2 is good (Sr=0.02; n= 4). The electrode loose 10-15 % of its original response after 3-4 month of regular using.
The developed method of hydrogen peroxide determination is selective. Because of the electrocatalytic nature of the current the reducing compounds (ascorbic acid, uric acid, urea) do not interfere with H2O2 determination.
The silica film is a promising matrix for encapsulation of different organic molecules and biomolecules including enzymes, antibodies, etc. Thus proposed method of the electrodes modification can be used for obtaining sensitive elements of chemical/ biochemical sensors.
The University is seeking companies or scientific laboratories which are interested to use the developed method for the construction of chemical/biochemical voltammetric sensors for environmental, food or biomedical application.
The desirable type of cooperation is a research cooperation agreement (the development of sensors based on the proposed sensitive elements).

Advantages & innovations

The using of mesoporous silica film helps to fix the nanoparticles onto the surface of the electrodes without decreasing their electroconductivity. The porous nature of the film enables small molecules of the substrate to diffuse to the catalytic centers of the nanoparticles onto the surface of the electrode. The small pores of the film do not allow the metal/ metal oxide particles washed from the surface. Thus stable analytical response of the modified electrode is obtained. The silica film is chemically and mechanically stable. The combination of metal/metal oxide nanoparticles and mesoporous silica film on the surface of planar screen printed electrodes was not described in the literature before. The film is ideal for incorporation of biomolecules (proteins, enzymes or antibodies ) inside. The encapsulated proteins will be in the close contact with metal/metal oxide nanoparticles. The last ones act as nanowires between protein active center and electrode surface. Such approach is perspective for the development of sensitive elements of the third generation mediator free biosensors. The planar screen printed electrodes are excellent transducers for voltammetric/ amperometric sensors because they are easy to use, cheap and need only 10-80 mkL of the sample. The sensors using planar electrodes as transducers can be easily miniaturized and integrated with a smartphone for the further application for point of care diagnostics.

Stage of development

Available for demonstration

Partner sought

The University is looking for entities are needed which have expertise in the production of analytical instrumentation, especially in the production of electrochemical equipment. The desirable type of cooperation is research cooperation agreement in the development of sensors based on the proposed sensitive elements (conversion of the information processing unit into a system on a smartphone).