H2S optical waveguide gas sensors based on chitosan/Au and chitosan/Ag nanocomposites

•Chitosan/Au, Ag composites were fabricated by “in situ” reduction of metal precursors.•Obtained composite coatings were characterized using UV–vis spectroscopy and TEM.•Obtained coatings were homogenous and had uniform distribution of nanoparticles.•The possibility of using obtained composite coatings as H2S sensor was shown.

In this work we present simple technique to fabricate chitosan based nanocomposite coatings containing Ag and Au nanoparticles and investigate the possibility of using these materials as sensitive layer of optical planar waveguide based nonreversible hydrogen sulfide sensors (chemidosimeters). It is shown that chitosan/Ag and chitosan/Au based sensors allows detection of hydrogen sulfide gas at concentration ranges 0.1–100 ppm and 5–300 ppm correspondently.