Remote gaseous acid sensing within a porphyrin-doped TiO2 sol-gel layer inside a structured optical fibre
G. Huyang, J. Canning, M. L. Åslund, M. Naqshbandi, D. Stocks, M. J. Crossley, University of Sidney (Australia)
A porphyrin containing sol-gel layer has been deposited within the interior of the channels of a silica structured opticalfibre. Gaseous HCl detection based on protonation of the porphyrin and observed as a change in the spectrum is demonstrated. This system is compared to previous work based on an acid sensor within a liquid-core fibre. The signalto-noise of this type of fibre system shows a higher level of sensitivity than the liquid-core and has a forty-fold acid diffusion rate increase due to the different medium for acidification.
