Olga Kazakova: Graphene sensors for ultrasensitive environmental monitoring

Quantum Detection, NPL, Teddington, UK  We demonstrate proof-of-concept graphene sensors for environmental monitoring of ultralow concentration NO2 in complex environments. Robust detection in a wide and environmentally relevant range of NO2concentrations, 10−154 ppb, was achieved, highlighting the great potential for graphene-based NO2sensors, with applications in environmental pollution monitoring, portable devices, automotive and mobile sensors for a global real-time monitoring network. The measurements were performed in a complex environment, combining NO2/synthetic air/water vapour, traces of other contaminants, and variable temperature in an attempt to fully replicate the environmental conditions of a working sensor. It is shown that the performance of the graphene-based sensor can be affected by co-adsorption of NO2and water at low temperatures (≤70 °C). However, the sensitivity to NO2 increases significantly when the sensor operates at 150 °C and the cross-selectivity to water, SO2, and CO is minimized. Additionally, it is demonstrated that single-layer graphene exhibits two times higher carrier concentration response upon exposure to NO2than bilayer graphene.  [1] Ch. Melios, et al., ACS Sensors. 3, 1666 (2018) Olga Kazakova received the Ph.D. degree in Solid State Physics from Institute of Crystallography, Russian Academy of Science in 1996. In 1999 – 2002, she was a first postdoctoral researcher and then an Assistant Professor at Chalmers University of Technology, Gothenburg, Sweden. Since 2002, she has been working at the National Physical Laboratory. Her research interests include functional (electronic, optical, structural) nanoscale studies of 2D materials; development of novel Scanning Microscopy techniques; novel sensors for Life Science and metrological applications. She is an author of ca 160 peer-refereed publications and had above 130 presentations at scientific conferences, e.g. ca 60 invited talks and seminars.   She was a recipient of the numerous national and international awards, including Intel European Research and Innovation Award (2008), NPL Rayleigh Award and Serco Global Pulse Award (2011). She is a Fellow of Institute of Physics.  Email: olga.kazakova@npl.co.uk  http://www.npl.co.uk/people/olga-kazakova