Chemically sensitive films for the detection of hazardous substances employing cyanine and nitroso near infrared dyes

Abstract

The sensing potential of commercially available near infrared (NIR) dyes for the detection of hazardous industrial substances such as hydrochloric acid, acetic acid and ammonia is reported. The NIR absorbing cyanine dyes DDI and IR-140 and the nitroso dye CI Acid Green 1, which have not been used in optical chemical sensors before, were entrapped within silicone and fluoropolymer films. These films were exposed to test atmospheres containing approximately 4% m/m concentrations of the hazardous vapours and their response was assessed by absorption spectroscopy. The sensing films could be used in the development of distributed optical fibre sensors since the polymer matrices are suitable for cladding silica optical fibres