| Literature DB >> 28158137 |
Cheng-Shane Chu, Jhih-Jheng Syu.
Abstract
An optical sensor for the dual sensing of oxygen (O<sub>2</sub>) and carbon dioxide (CO<sub>2</sub>) based on sensing films coated on filter paper is proposed. Ethyl cellulose (EC) doped with platinum(II) meso-tetrakis(pentafluorophenyl)porphyrin (PtTFPP) and 7-amino-4-trifluoromethyl coumarin serve as the oxygen sensing material and reference blue emission dye for the pH indicator, respectively. The CO<sub>2</sub> sensing layer includes the pH-sensitive fluorescent indicator 1-hydroxy-3,6,8-pyrenetrisulfonic acid trisodium salt immobilized within the EC. The O<sub>2</sub>- and CO<sub>2</sub>-sensitive materials can both be excited with a 405 nm LED, and the two emission wavelengths can be detected separately. The experimental result reveals that the optical O<sub>2</sub> and CO<sub>2</sub> sensors have sensitivities of I<sub>N<sub>2</sub> </sub>/I<sub>100%O<sub>2</sub> </sub>=22.8 and I<sub>N<sub>2</sub> </sub>/I<sub>100%CO<sub>2</sub> </sub>=3.6, respectively. The response times of the optical O<sub>2</sub> sensor were 15 s upon switching from nitrogen to O<sub>2</sub> and 41 s when moving from O<sub>2</sub> to nitrogen (N<sub>2</sub>). The response times of the optical CO<sub>2</sub> sensor were 7 s upon switching from 100% N<sub>2</sub> to 100% CO<sub>2</sub> and 39 s when moving from 100% CO<sub>2</sub> to 100% N<sub>2</sub>. The proposed optical dual sensor can be used for the simultaneous sensing of O<sub>2</sub> and CO<sub>2</sub> concentrations in environmental applications.Entities:
Year: 2017 PMID： 28158137 DOI： 10.1364/AO.56.001225
Source DB: PubMed Journal: Appl Opt ISSN： 1559-128X Impact factor: 1.980