Quick production of gold electrode sets or arrays and of microfluidic flow cells based on heat transfer of laser printed toner masks onto compact discs

Abstract

A process is described to speedily produce in the laboratory, single or multiple coplanar gold electrodes of any shape and with sizes ranging from 100 μm to 10 cm, as well as to assemble microfluidic flow cells with them. The innovative combination of simple processes for ad hoc design and production uses readily available equipment and inexpensive materials, like recordable compact disks of the gold sputtered type. The following steps are involved: drawing of the electrode(s) on a microcomputer; laser printing of the design on wax paper; heat-transfer of the toner onto the gold surface of a peeled CD-R; etching of the gold layer from unprinted regions; removal of the toner with a solvent; activation; and use in conventional batch or flow cells. To obtain microfluidic flow cells with 7–12 μm interlayer gap, a gasket spacer of the desired shape is drawn and laser printed, the toner layer is heat transferred onto one CD piece with pre-etched electrodes and a second CD section is heat-sealed on top of it. The functionality of these electrodes as well as of the microfluidic flow cells is demonstrated by voltammetry and flow injection amperometric analysis.