Laser etched carbon fibre composites: Disposable detectors for flow analysis applications

Laser etching techniques have been used to selectively core polyester-carbon fibre mesh composites to yield a fibrous channel structure. The fibres retain their conductivity and when sandwiched within flow assemblies have been shown to provide a versatile electrode substrate that can be used as an inexpensive electrochemical detector. The influence of the laser treatment has been characterised in terms of both the physical erosion of the underlying carbon fibre network and in the resulting electrochemical behaviour towards model analytes. The viability of using the fabrication system as a detector for use in liquid chromatographic or flow injection analysis has been evaluated using ascorbate, sulphite, nitrite and nitrate under a variety of detection regimes. Modification of the fibre network with electrodeposited copper has been shown to facilitate the detection of nitrate and sulphite and a strategy for transferring the technology to other formats is critically appraised.