Debye Capacitive Sensor for Biomolecular Detection
M.S. Mannoor, T. James
Microelectronics Research Center, New Jersey Institute of Technology, US
capacitive sensor, debye length, Dielectric Spectroscopy, electrode polarization, DNA Hybridization
A novel NEMS capacitive sensor with electrode separation in the order of Debye length is introduced to provide high sensitivity for detecting biomolecular interactions at low frequency. By reducing the electrode separation to the order of the electrical double layer width (Debye Length), we were able to zero in on the changes occurring within the double layer as a result of oligonucleotide hybridization. In comparison to the previously reported change of 2-3% we observed a 25-30% change in capacitance at 10Hz as a result of hybridization. The interaction between the electrical double layers due to the reduced electrode separation decreased the potential drop across the electrode spacing thus making low frequency dielectric measurements possible.
Nanotech 2008 Conference Program Abstract