Integration of Organic Electronics and Aqueous Microfluidics for Biosensing
01 January 2002
Organic and polymer semiconductors have the required electronic properties to transduce ambient chemical information to electronic information in a circuit1-8. In many cases, including biological systems, the "ambient" is an aqueous solution. Although water is often thought to be detrimental to organic semiconductor devices such as thin-film organic field-effect transistors (OFETs)9,10, we show that it is possible to operate such devices under a flow of water. Furthermore, we have successfully integrated microfluid flow channels with OFETs such that water flow occurs perpendicular to the current flow direction with the fluid in contact with the active region of the device. Tests of several combinations of semiconductors and dissolved hydroxy and carboxy compounds reveal that there is some specificity to the electrical response, even in the absence of defined receptors attached to the semiconductors. Thus, the use of arrays of OFETs and novel information processing algorithms will likely permit analyte identification. The devices are sensitive to chemical concentrations down to the 1 ppm range. The use of carefully designed chemical receptor groups will further enhance this sensitivity. We suggest that this technology will be useful in sensing biological agents in an aqueous environment.