The most important role played by bioelectronics is related to the detection of small biological molecules, i.e. biosensors. Various principles like electrochemical, optical, immunological and others may be applied. The decisive advantage of microelectronics lies in the perspectives for miniaturization. In the last years, a steadily increasing number of functionalities could be integrated into microelectronic chips - as could directly be observed by us for the case of ever smarter becoming smart phones. The figure displays a sensor chip that has been developed for glucose detection with an affinity assay and which occupies an area of 1.3 x 0.4 mm only. The transformation cascade is shown on the top, by which the signal transduction via visocosity η, beam deflection z, capacitance C, frequency f and switching time tsw is performed. At the bottom of the figure, the legends indicate the electronic modules carrying out these transformations (ROC = ring oscillator circuit). The microchip has been demonstrated to measure glucose concentrations cg in the relevant physiological range from 0 to 30 mM/L.
Technical University of Berlin - Bioelectronics