PROSPECTIVE DIRECTIONS FOR THE IMPLEMENTATION OF SOL-GEL TECHNOLOGY IN THE SYNTHESIS OF ZINC OXIDE NANOSCALE FILMS IN SPR SENSORS

An analysis of the materials used for the manufacture of sensitive elements of PPR sensors was carried out. Zinc oxide is a promising material for optoelectronics. It is heat-resistant, has anti-corrosion and antimicrobial properties, is environmentally safe and cheap, and is also characterized by high biocompatibility. Therefore, this material is attractive for use as an additional nanolayer of a SPR sensor. The main technologies of applying zinc oxide on a layer of gold are considered. It was determined that the sol-gel technology has a number of advantages, namely: it does not require expensive equipment and special premises, it allows to simultaneously applying a film to a large batch of samples. Conducted studies on the application of an additional nanolayer of zinc oxide on the SPR-sensitive element revealed that this layer has protective properties - when annealed at 500°C, the gold nanolayer retains its sensory properties and the film does not collect into droplets. That is, this additional layer prevents the surface diffusion of gold atoms to create droplets that have lower energy compared to the film. The detected effect may be related to the fact that there are residual zinc atoms in zinc oxide, which come into contact with gold atoms and interfere with their surface diffusion. This hypothesis is consistent with the following facts: gold forms alloys with zinc, but these alloys are brittle. That is, zinc atoms in gold alloys prevent the movement of dislocations in the gold lattice. It is shown that the application of an additional sol-gel nanolayer of zinc oxide on the surface of the sensitive element of the SPR sensor creates a complex of positive properties, namely: it improves its sensitivity due to a significant reduction of stresses in the gold nanolayer during annealing using sol-gel technology and, in addition, increases the life of the sensitive element because this additional layer prevents the gold layer from wearing away. Therefore, an additional nanolayer of zinc oxide made it possible to create an improved PPR-sensitive element. Prospective areas of use of the improved sensitive element in the future are proposed for the control and research of substances in veterinary medicine, microbiology, food and ceramic and abrasive industries