In the talk, the activities of the Institute of Electrical Measurement and Sensor Systems at the Graz University of Technology in the field of aerosol sensing will be presented. The attention will be paid to several topics covering air quality assessment related to combustion sources as well as design aspects for miniaturized on-chip sensors.In the first part, new methods developed within the Horizon 2020 funded project City Air Remote Emission Sensing (CARES) for the remote detection of traffic-related particle emissions will be presented. These particles are of major concern since studies suggest severe health effects leading to premature deaths even at low levels of exposure. The second part deals with challenges in miniaturizing aerosol sensors. A close-meshed and wide-area monitoring has up to now failed due to the size, complexity and cost of the currently available sensor concepts. The aim of this work is to explore the possibility to use novel aerosol sensing concepts for PM2.5 sensing. Major aspects of the sensor design are the compatibility to standard CMOS processes combined with System in Package (SiP) solutions leading to cost efficiency and relatively easy scalability, which both are premises for a dense sensor network. The third part shows first results of a recently developed low cost, low energy Black Carbon (BC) sensor. BC is of special interest due to its global warming as well as toxic potential.