We propose a novel optical gas recognition thin film layer of 4-[bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-amino]phenol on quartz substrates. The gas optical response to the following analytes have been investigated as air pollutants (SO2, NO2, CO, CH4 and NH3). The spin-coated pyrazole layer appears to have reversible sensitivity towards SO2 and very low and irreversible sensitivity for NO2.