Multiple diagnostic analyses by enzymatic and chemical reaction on a PDMS microchip

Microfabrication techniques have been applied to biochemical microreactions and separations on a microchip. The major advantages of biochemical analysis on a chip are reduced reagents, fast reaction, automation, high throughput and portability. The authors report in this paper the development of a multiple diagnostic analyzing system with polydimethylsiloxane (PDMS) microchip. A PDMS microchip is suitable for single-use to avoid cross-contamination in a clinical diagnostic test. Because the PDMS microchip can be produced inexpensively by replica molding with microfabricated master and used with simple optical detection device instead of expensive electrode due to its transparency. Two major blood tests, glucose and albumin assay, were demonstrated on the system by the combination of enzymatic acid chemical reactions and CCD image processing techniques. Ongoing research is to develop a system with sufficient numbers of assays for an easy health checkup. For example, the authors are trying to integrate other enzymatic reactions for blood tests using Oxidase/POD method for uric acid, cholesterol, triacylglycerol and so on.