Laser-deposited carbon aerogel derived from graphene oxide enables NO2-selective parts-per-billion sensing

4 figures.Laser-deposited carbon aerogel is a low-density porous network of carbon clusters synthesized using a laser process. A one-step synthesis, involving deposition and annealing, results in the formation of a thin porous conductive film which can be applied as a chemiresistor. This material is sensitive to NO2 compared to ammonia and other volatile organic compounds and is able to detect ultra-low concentrations down to at least 10 parts-per-billion. The sensing mechanism, based on the solubility of NO2 in the water layer adsorbed on the aerogel, increases the usability of the sensor in practically relevant ambient environments. A heating step, achieved in tandem with a microheater, allows the recovery to the baseline, making it operable in real world environments. This, in combination with its low cost and scalable production, makes it promising for Internet-of-Things air quality monitoring.This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 642742. R.A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through Project Grant MAT2016-79776-P (AEI/FEDER, UE) and from the European Union H2020 programs “ESTEEM3” (823717), Flagship Graphene (881603), FLAG-ERA - Graphene (MICINN) GATES (PCI2018-093137). WKM and ABM further acknowledge the Gobierno de Aragon (Grupos Reconocidos DGA T03_17R (FEDER, UE) and T03_20R)