Optical probes based on optical fibers and single-walled carbon nanotubes for hydrogen detection at cryogenic temperatures

In this letter, preliminary results on the feasibility to use optical fiber sensors coated by single-walled carbon nanotubes (SWCNTs)-based sensitive materials for hydrogen detection at cryogenic temperatures are presented. The optical probes have been realized by the Langmuir-Blodgett deposition of close-end and open-end SWCNTs on the distal end of standard optical fibers. The results obtained from hydrogen detection testing, carried out at a temperature as low as 113 K, demonstrate the excellent potentiality of the proposed configuration to sense very low percentages of gaseous hydrogen (< 5%), with good recovery and reversibility features as well as fast response times. (c) 2006 American Institute of Physics.