Our latest paper, published in Sensors and Actuators B, describes a highly sensitive device for detecting and quantifying the concentration of carboxylic acid. The work is part of an on-going collaboration between the Department of Engineering Photonics at Cranfield University and The Graduate School of Environmental Engineering at the University of Kitakyushu, Japan, exploiting optical fibre based sensing platforms developed at Cranfield with the novel functional materials and coating techniques investigated by Prof Lee's group at Kitakyushu.
The operation of the sensor is based on the measurement of the change in refractive index of a functional coating deposited onto the cladding of the optical fibre. Mesoporous thin films were fabricated using the layer-by-layer self-assembly of poly(allylamine hydrochloride) (PAH) and silica nanospheres (SiO2) with a diameter in the range of 40–50 nm. The amino (NH2) functional group of PAH was used as the binding site for the detection of ACAs. High sensitivity to benzoic acid and mellitic acid, respectively, was observed. The lowest measured concentration of 1 nM of mellitic acid was detected selectively over structurally(phenol) and functionally (acetic acid) related compounds.
Pronounced aromatic carboxylic acid detection using a layer-by-layer mesoporous coating on optical fibre long period grating
S Korposh*, T Wang*, S W James, R P Tatam, and S-W Lee*
Sensors and Actuators B (2012).
As always, a full list of publications from the Department of Engineering Photonics is available here.