A fully disposable paper-based electrophoresis microchip with integrated pencil-drawn electrodes for contactless conductivity detection

We describe for the first time the fabrication of a paper-based microchip electrophoresis (pME) device with integrated hand-drawn pencil electrodes to perform capacitively coupled contactless conductivity detection (C4D). This low-cost device (less than $0.10) revealed great capability to dissipate heat, good injection-to-injection repeatability, and ease of attaching pencil-drawn electrodes on the separation channel. The feasibility of the proposed pME-C4D device was successfully demonstrated with the separation of bovine serum albumin and creatinine within 150 s with baseline resolution. The limits of detection values for albumin and creatinine were 20 and 35 mu mol L-1, respectively. These biomolecules present clinical relevance as evidence of kidney failure. The proposed pME-C4D offers great potential to be explored in the diagnosis of diabetesmellitus and heart disease.