Electrochemical biosensing has been generally considered to be highly efficient. However three-dimensional numerical analysis has revealed that only a fraction of an analyte is consumed for amperometric detection in a flowing stream. To improve the collection efficiency and the sensitivity of detection, micropillar electrodes were fabricated. Furthermore, a gold black layer was formed on the surface of the micropillars. In the best case, a 22-fold increase was observed in the generated current compared with a flat electrode. The micropillar electrodes were also used to conduct an electrochemical enzyme linked-immunosorbent assay.