Effect of varying chain length of n-alcohols and n-alkanes detected with electrostatically-formed nanowire sensor

•Detection of n-alcohols (polar) and n-alkanes (non-polar) with electrostatically-formed nanowire (EFN) sensor.•Alkyl chain length of target n-alcohols and n-alkanes demonstrated a direct correlation to the sensor response.•Sensor response achieved without any explicit modifications on the SiO2 molecular gate of the EFN sensor.•Sensor operation at room temperature.

Recent experimental investigations on the electrostatically-formed nanowire (EFN) sensor have led to promising results for gas phase chemical detection. Herein, we elaborate on the EFN sensor performance by systematically varying the alkyl chain length of target n-alcohols and n-alkanes. We observe that in addition to the polar target molecules, the sensor is also capable of detecting non-polar alkanes without any explicit additional surface treatment. Moreover, there is a noted increase in the sensor response commensurate with the increasing alkyl chain length for both the alcohols and alkanes tested. The underlying mechanism responsible for the observed phenomena is attributed to an interplay between the alcohol/alkane-silicon oxide interaction, induced surface EFN electric field and inherent molecular properties of our target species.