biostudies-literatureTuerdi GNational Natural Science Foundation of China5614-5621https://www.ebi.ac.uk/biostudies/studies/S-EPMC9078192biostudies-literatureUnknown8(10)5,10,15,20-Tetraphenylporphyrin (TPP) was synthesized, and a glass optical waveguide (OWG, which restricts and maintains the light energy in a specific, narrow space and propagates along the space axially) was coated with a gas-phase protonated TPP thin film to develop a sensor for NH<sub>3</sub> gas detection. The results show that the TPP thin film agglomerated into H-based J-type aggregates after H<sub>2</sub>S gas exposure. The molecules in the protonated TPP film OWG sensor acted as NH<sub>3</sub> receptors because the gas-phase protonated TPP film morphologically changed from J-type aggregates into free-base monomers when it was deprotonated by NH<sub>3</sub> exposure. In this case, H<sub>2</sub>S gas could be used to increase the relative amount of J-type aggregates in the TPP film RSC advancesOptochemical properties of gas-phase protonated tetraphenylporphyrin investigated using an optical waveguide NH<sub>3</sub> sensor.PMC907819221765021Tuerdi GYimit ANizamidin PWang FKari NfalseOptochemical properties of gas-phase protonated tetraphenylporphyrin investigated using an optical waveguide NH<sub>3</sub> sensor.5,10,15,20-Tetraphenylporphyrin (TPP) was synthesized, and a glass optical waveguide (OWG, which restricts and maintains the light energy in a specific, narrow space and propagates along the space axially) was coated with a gas-phase protonated TPP thin film to develop a sensor for NH<sub>3</sub> gas detection. The results show that the TPP thin film agglomerated into H-based J-type aggregates after H<sub>2</sub>S gas exposure. The molecules in the protonated TPP film OWG sensor acted as NH<sub>3</sub> receptors because the gas-phase protonated TPP film morphologically changed from J-type aggregates into free-base monomers when it was deprotonated by NH<sub>3</sub> exposure. In this case, H<sub>2</sub>S gas could be used to increase the relative amount of J-type aggregates in the TPP film 2018-01-01T00:00:00Z2018 Jan2025-04-05T13:24:34.442Z2025-04-05T13:24:34.442ZS-EPMC90781923554242810.1039/c7ra11643h