Detection of Ethylenediamine Vapor by Optical Waveguide Sensor Based on Tetrakis-Carboxylphenyl Porphyrin Film

sensitive element was prepared by the spin coating method on the surface of a K + exchange glass optical waveguide by dissolving tetrakis-carboxyphenyl porphyrin (TCPP) in the nontoxic solvent ethanol. The TCPP sensitive element detected 18 volatile organic compounds with an excellent selective response to ethylenediamine (EDA) gas. On this basis, the effects of the solvent, solution mass fraction, speed of the homogenizer and atmospheric humidity on the detection of EDA gas by the sensitive element were discussed. The formation of hydrogen bonds between TCPP and EDA molecules is proposed, which leads to changes in the morphology and light absorbance of the sensing film.