Screen-printing technology developement

Biosensors for the determination of blood glucose have enjoyed widespread commercial success since the introduction of the pen-sized 30 s blood glucose meter [10]. However, researchers have continued to devise novel approaches in the development of amperometric biosensors based on screen-printing technology Table 23.1 summarises some examples of these approaches together with their performance characteristics. 

Riviere, B., Viricelle, J. P. and Pijolat, C. (2003) Development of tin oxide material by screen-printing technology for micro-machined gas sensors. Sensors and Actuators B Chemical 93,531-7. 

The original electrode was developed for detecting urea in blood and urine samples. An enzyme sensor for measuring urea in milk has been reported by an Indian group [31]. The working principle is identical to that of Guilbault s sensor. The sensor prepared for milk analysis, however, is a flat cell fabricated with screen-printed technology. 

Australia, and scaled up by BP Solar in Spain, the heterojunction with intrinsic thin layer (HIT) cells developed by Sanyo by replacing the diffused P-doped emitter with an amorphous silicon layer and the back contact cells developed by Stanford University for use in concentrator technology and now converted to a large area for flat plate use. All three use single-crystalline silicon, while the majority of screen-printed cells use multicrystalline silicon wafers. 

Most electrochemical immunosensors use screen-printed electrodes produced by thick-film technology as transducers the importance of screen-printed electrodes in analytical chemistry is related to the interest for development of disposable and inexpensive immunosensors. A thick-film is based on the layers deposition of inks or pastes sequentially onto an insulating support or substrate the ink is forced through a screen onto a substrate and the open mesh pattern in the screen defines the pattern of the deposited ink. 

Electrochemical immunosensors are valid tools for the measurement of environmental pollutants such as PCBs. These devices are based on the principles of solid-phase immunoassays and couple the specificity of the immunoassay test to the sensitivity of electrochemical techniques. Screen-printed electrodes are used in the immunosensor development, because they can have a field use and their technology allows mass production at low cost. 

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