The objective of S3 is developing breakthrough technologies in gas sensing that will provide higher sensitivity and selectivity at reduced cost. This objective will be pursued by bringing together excellence and complementary skills of ropean Union and Russian groups. Enhanced sensitivity and selectivity will enable toxic and explosive gases to be detected against a background of air constituents and ubiquitous air contaminants. This task will be pursued by studying sensors and sensing principles based on semiconductor nanowires (NWs) molecularly engineered, in terms of doping level, the used additives and /or functionalization processes and heterostructures and deposited onto SiO2/Si and/or alumina MEMS heater platforms. These platforms will be configured in innovative ways to obtain multiple signals from one and the same sensitive layer. Signals recovered will include resistive, field-effect, ion emission and catalytic/thermal conductivity response of the NW materials. Low power operation and additional enhancements in selectivity will be obtained through pulsed-temperature operation and combined self-heated operation mode using dynamic and steady state responses and modulated optical excitation. Furthermore, the increased stability of NW-based sensing materials will positively affect the reliability of the developed sensors. In order to meet application demands, S3 will further explore novel concepts of sampling, filtering and preconcentration of target substances based on nanostructured filter and enrichment materials. The development and the modelling of this new generation of nanostructured gas-sensing and ion emitting materials will be supported by a wide range of morphological and physico-chemical characterisation techniques. The cooperation between EU Union and Russian groups will be improved and strengthened by short and long term exchanges of researchers, the organization of common workshops and tutorials and the establishment of joint doctoral degrees