A novel design approach for developing chemical sensing platforms using inexpensive technologies

In this paper we describe a novel design methodology for fabricating chemical sensing platforms by utilising well-established inexpensive technologies. In our approach, the sensing site and the active part of the transducer are designated as two separate entities, facilitating the use of a multitude of sensing membranes and/or supporting substrates as well as the employment of discrete off-the-shelf devices. The versatility of this method is demonstrated through prototype chemical sensing platforms based on Pt/Si_xN_y and Au/TiO₂ sensing sites, fabricated on glass-microscope slides and printed circuit boards respectively, with discrete MOSFETs integrated on the same platforms. Finally, this concept was further exploited by designing and fabricating a universal instrumentation board that incorporates both the active transducers as well as appropriate read-out circuitry, demonstrating near to Nerstian chemical sensitivities.