Biopolytronics for the computer-assisted fabrication of bioelectronic devices

For many years, the electronic transducers have been dominated by inorganic materials. However, mechanical flexibility is often necessary as this would allow the integrated circuits to be twisted, bent and rolled without any effect on the electrical characteristics of the device. On the basis conducting polymers have attracted much interest for the development of biosensors due to their propertiesto be excellent materials for immobilization of biomolecules, favouring the rapid transfer of the charges produced by the biochemical reactions to the electronic circuitry used for the signal elaboration. In 2000 Sirringhaus et al. (Science 290, 2123) have demonstrated a direct inkjet printing of complete transistor circuits, based on solution-processed polymer conductors, insulators and self-organizing semiconductors and recently we have developed a set of techniques for the realization of computer-assisted design and fabrication of third generation biosensors based on synthetic macromolecules, as charge-transfer mediators and protective layers, and biological molecules, as sensing elements (Setti et al., 2005), which was named biopolytronics. With ink jet technology, virtually any complex bioelectronic pattern can be directly printed to a flexible or rigid surface in the size of a pixel using electronic and biological inks, giving very high-resolution patterns. Here we present an overview on biopolytronics reporting possible approaches for formulating biologically and electronically active water-based inks for thermal inkjet technology, containing respectively different enzymatic activities (redox enzymes such as glucose oxidase and peroxidase) and conjugated polymers (conducting polymers such as PEDOT/PSS and regioregular poly(3-hexylthiophene), r-P3HT), opening the way for a wide range of possibilities in the realization of bioelectronic devices using inkjet technology.