Microelectrodes on a silicon chip for label-free capacitive DNA sensing

This paper presents the experimental characterization of two-terminal microfabricated capacitors for microarrays with an electrical sensing of label-free deoxyribonucleic acid (DNA). So far, such a concept has been demonstrated only in experimental setups featuring dimensions much larger than those typical of microfabrication. Therefore, this paper investigates: 1) the compatibility of the silicon microelectronic processes with biological functionalization procedures; 2) the effects of parasitics when electrodes have realistic dimensions; 3) measurement stability and reproducibility; and 4) the possibility of a fully integrated stand-alone device. The obtained results clearly indicate that two-terminal capacitive sensing with fully integrated electronics represents a viable technology for a DNA label-free detection/recognition.