Chemical-recognition-driven selectivity of SnO2-nanowire-based gas sensors

•Proposing a simple and an efficient method to modulate the selectivity of the gas sensor.•Use of SAM molecules with different chemical moieties for tuning the selectivity of SnO2 nanowires-based gas sensors.•Adsorbed SAM molecules acted as a passivation layer and lowered the base resistance and the operating temperatures.•Gas sensing studies showed distinct selectivity behavior for each SAM molecules.•Molecular dynamic simulation further supports the selective gas sensing mechanism.