Solid-state reference electrode based on electrodeposited nanoporous platinum for microchip

A new solid-state reference electrode operating in buffered aqueous solution for electrochemical system on microfluidic chip is reported. The anodized nanoporous platinum showed its usefulness as a solid-state reference electrode owing to near-Nernstian behavior, low hysteresis, and quick response. The presence of redox couples such as Fe(CN)(6)(3-/4-), bringing about significant interference, can be successfully suppressed by an electropolymerized poly-1,3-phenylendiamine (poly-m-PD) layer on the nanoporous platinum surface. Since the poly-m-PD coated nanoporous platinum oxide responds exclusively to pH, its potential should be constant and stable in a buffer solution. The nanoporous platinum oxide with poly-m-PD film is easy to produce and is particularly compatible with microfabrication. The experimental results in this study demonstrate that the proposed system successfully works as a solid-state reference electrode that should be integrated on microchips for microanalysis systems.