An RF Circuit Model for Interdigital Capacitors-Based Carbon Nanotube Biosensors

We present improved RF circuit modeling of a biosensing element based on a single-walled carbon nanotube combined interdigital capacitors at microwave frequencies. From the resultant circuit, the lumped element values for biomolecular binding are accurately obtained. It is thereby found that the completed RF circuit model shows excellent agreement with measured results. This implies that the electrical properties of a specific biomolecular binding system can be quantitatively analyzed if an optimal RF circuit model is constructed. Finally, we suggest that the suggested methodology can be used to analyze other biomolecular sensing methods.