Radio-Frequency Tank Circuit for DNA Sequencing

Abstract

DNA sequencing by now is a ubiquitous technique in biology and medicine. Nanopore sequencers turn out to be a promising approach for high-speed sequencing of long DNA-strands while cutting costs by many orders of magnitude.We present a resonant RLC-circuit operating at radio frequency (Bhat, Soft Nanoscience Letters (2013)). DNA is driven through a nanopore which causes a shift in the resonance of the circuit. The nanopore is embedded within a resonant CPW structure, a so-called tank circuit that enables the measurement of extremely small capacitance changes caused by the transition of the macromolecule through the pore. In contrast to existing nanopore-sequencing technologies, such a design does not rely on a molecular motor to slow down the translocating DNA. Furthermore, the presented method is not limited by the length or a specific design of the pore, allowing a plethora of pore modifications and designs to be used.Finite element simulation techniques provide an insight into the behavior of different tank-circuit geometries. We present several studies on how the circuit geometry can be modified to increase the sensitivity. Additionally, different concepts for amplification of the atto-Farad signal levels are discussed (Ramachandran et al., Applied Physics Letter 99 (2011)), a degree of sensitivity sufficient for resolving the different DNA bases and paving the way for DNA sequencing in the MHz regime.