- Abstract 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.