CURRENT TRENDS IN THE DEVELOPMENT OF GAS DETECTORS OF TOXIC SUBSTANCES

The main trends in the creation of sensitive elements of gas sensors for the detection of toxic substances in polluted areas, in industrial premises and the atmosphere are analyzed. An important aspect of the application of gas sensors is the monitoring of the quality of food products, especially of animal origin, since the consumption of spoiled products can be a great danger to human health. The principles of operation and new directions in the field of gas sensor technologies based on thin films of polymers and their nanostructures and composites with semiconductor materials of various types are outlined. Modern trends in the creation of detectors of harmful substances involve the use of new sensor media based on nanostructured components of various nature and the formation of thin film structures, using new, advanced nanotechnological approaches. It is promising to use new compositions of indicator substances (copolymers and layered structures based on poly-3,4-ethylenedioxythiophene, polyanisidine, pentacene, carbon and silicon nanoclusters), and new technological methods of their formation ("in situ" polymerization, layered assembly, electropolymerization and etc.), which do not require the use of complex, expensive equipment. The principles of construction of multifunctional gas sensors are presented. The construction of a gas sensor is proposed, the information signal of which is determined by the selective absorption of the optical medium interacting with the gas. To obtain spectral characteristics, optocouples are used, which consist of controlled sources of optical radiation and photosensitive elements. The key issue for the successful implementation of all improvements in gas sensors and nanosensors at the current stage will remain the search for substances and structures that are highly sensitive to the action of toxic gases, including components of explosive and poisonous substances, and can selectively react to their presence by changing optical and/or electrical properties.