The design and function of an amperometric dual-microelectrode is communicated which can operate as a collection sensor. The device consists of two individually addressable microelectrodes of parallel cylindrical geometry. Dual-cylinder microelectrodes have been prepared from micrometre platinum wire and carbon fibre to extremely good precision using a microscope fabrication technique. The shielding and feedback properties of the new microelectrode assembly have been evaluated with respect to electrode separation For the case of the hexacyanoferrate (iii)/(ii) couple. Carbon fibre (CF) devices with cylinder length of 585 mu m are suitable for the cycling of organic redox couples between narrow gap electrodes. A discussion follows reporting the selective sensing of 1,4-dihydroxybenzene at a narrow gap CF device where the chemical and electrochemical effects of ascorbate interferences are Largely filtered out to concentrations of 200 mu M.