Oxygen functionalised epitaxial graphene sensors for enhanced polar organic chemical vapour detection

Oxygen functionalised epitaxial graphene (OFEG) chemiresistor sensors were fabricated for sensing polar organic analyte vapours in the ambient atmosphere. The electrical characteristics of the sensor showed an increase in resistance to polar protic analytes, whilst the resistance decreased upon exposure to polar aprotic vapours. The OFEG sensors showed a significant increase in response time and an order of magnitude improvement in the recovery time in comparison to non-functionalised epitaxial graphene (NFEG) sensors. A strong correlation between the dipole moment of an analyte and the magnitude of the response was observed, where OFEG sensors showed a large linear increase in the magnitude of response in comparison to a small nonlinear change in resistance for NFEG sensors.