resumo
In this article, we report the analysis of a novel optical fiber pH sensor based in polyaniline (PAni) coating applied on a trenched core-free (only-bridge) silica fiber. The results are compared to another pH sensor based on side-polished silica fiber. The pH-sensitive polymer is synthesized over the fiber sample by means of oxidative polymerization, keeping records of the time where the reaction occurs to improve the sensitivity. The response to pH is enhanced in the case of the trenched core-free bridge fiber due to the higher interaction of the evanescent field with the PAni film and, thus, the surrounding media. The sensitivity in the linear zone of operation is 1.1 mW/pH, and a total transmittance of 55% in the pH range is 4.2-8.1. The repeatability of both sensors was checked, showing a high capability to perform studies in liquid samples due to its temperature independence, good sensitivity, and long-term stability.
palavras-chave
FABRICATION; GRATINGS; LAYER
categoria
Engineering; Instruments & Instrumentation; Physics
autores
Rodriguez, A; Lopes, G; Nedoma, J; Pereira, SO; Fernandes, AJS; Jamier, R; Roy, P; Bravo, M; Lopez-Amo, M; Marques, C
nossos autores
Carlos Marques
Professor Auxiliar
Sónia Oliveira Pereira
Bolseiro de investigaçãoProjectos
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was supported in part by MCIN/AEI/10.13039/501100011033 under Project PID2022-137269OB-C21 and Project TED2021-130378B-C22; in part by the Fondo Europeode Desarrollo Regional (FEDER) "A way to make Europe;" in part by the European Union "Next Generation EU"/PRTR; in part by Beatriz Galindo in MICINN under Grant BEAGAL18/00116; in part by the CICECO-Aveiro Institute of Materials under Project LA/P/0006/2020,Project UIDB/50011/2020, and Project UIDP/50011/2020; in part by i3N under Project UIDB/50025/2020, Project UIDP/50025/2020, and Project LA/P/0037/2020; in part by DigiAqua under Project PTDC/EEI-EEE/0415/2021; in part by the National Funds through the Portuguese Science and Technology Foundation/MCTES (FCT I.P., Portugal); in part by the European Union through the Research Excellence For Region Sustainability and High-Tech Industries (REFRESH) under Project CZ.10.03.01/00/22_003/0000048 via the Operational Program Just Transition; and in part by the Ministry of Education, Youth, and Sports of the Czech Republic through the VSB-Technical University of Ostrava under Grant SP2024/081 and Grant SP2024/059. Open access funding provided by Universidad Publica de Navarra.