A long period grating optical fiber sensor with nano-assembled porphyrin layers for detecting ammonia gas

SENSORS AND ACTUATORS B-CHEMICAL

卷:228

Article

Wang, Tao¹  Yasukochi, Wataru¹  Korposh, Sergiy²  James, Stephen W.³  Tatam, Ralph P.³  Lee, Seung-Woo¹ 

[1] Univ Kitakyushu, Grad Sch Environm Engn, 1-1 Hibikino, Kitakyushu, Fukuoka 8080135, Japan

[2] Univ Nottingham, Dept Elect & Elect Engn, Nottingham NG7 2RD, England

[3] Cranfield Univ, Sch Engn, Dept Engn Photon, Cranfield MK43 0AL, Beds, England

关键词: Long period grating (LPG);    Optical fiber;    Porphyrin;    Self-assembly;    Ammonia;    Refractive index;   

DOI  :  10.1016/j.snb.2016.01.058

来源: Elsevier

【 摘 要 】

In this study, the ability of a long period grating (LPG) optical fiber sensor coated with a multilayer film of poly(diallyldimethyammonium chloride) (PDDA) and tetrakis(4-sulfophenyl)porphine (TSPP) to detect ammonia gas was demonstrated. The nano-assembled thin film was prepared using a layer-by-layer deposition technique. This combination of an LPG and TSPP could allow highly sensitive optical sensors that specifically bind ammonia to be fabricated. An LPG with a period of 100 pin and a PDDA/TSPP coating produced by depositing fifteen layers afforded a limit of detection of 0.67 ppm for ammonia gas. TSPP molecules in the film acted as ammonia receptors because the TSPP morphologically changed from J- or H- aggregates to free base monomers when it was deprotonated by being exposed to ammonia. Interestingly, HC1 vapor could be used to increase the relative amount off-aggregation in the TSPP and to restore the sensor response. The reversibility of the morphological change in the TSPP allowed reversible changes to occur in the properties of the coating, including the refractive index, film thickness and density, and electrostatic interactions; these influenced the transmission spectrum of the LPG. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free