In this paper, we present the results of a new pH sensor based on a polyaniline (PAni) coating on the surface of a tilted fiber Bragg grating. The pH-sensitive PAni was deposited by in situ chemical oxidative polymerization. The performance of the fabricated pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device. It was found that the sensor exhibits response to pH changes in the range of 2-12, achieving a sensitivity of 46 pm/pH with a maximum error due to the hysteresis effect of ±1.14 pH. The main advantages of this PAni-TFBG pH sensor are biochemical compatibility, temperature independence, long-term stability and remote real-time multipoint sensing features. This type of sensor could be used for biochemical applications, pipeline corrosion monitoring or remote-multipoint measurements.Á. González-Vila is supported by the F.R.S.-FNRS through a FRIA grant. C. Caucheteur is supported by the F.R.S.-
FNRS. The authors would also like to thank the financial support from the ERC (European Research Council) Starting
Independent Grant PROSPER (grant agreement No. 280161 – http://www.umons.ac.be/erc-prosper), from the Spanish
Comisión Interministerial de Ciencia y Tecnología within projects TEC2016-76021-C2-1-R and TEC2013-47264-C2-2-
R and from SUDOE ECOAL-MGT and FEDER funds from the European Union. The authors also acknowledge the
financial support of CAPTINDOOR WBGREEN programs (Walloon Region of Belgium)
