Abstract
Sensors based on nanogap capacitance changes are being developed for genomic and proteomic applications because they offer label-free detection on platforms amenable to high throughput configurations. We compare impedance spectroscopy measurements with a rigorously characterized model that predicts the impedance spectrum of these devices based on geometry. Sensitivity to permittivity changes is also predicted by the model and compared to the measured values in the frequency range from 1 Hz to 3 MHz. The lowest detection limit for the magnitude of the impedance (∫Z∫) is in the region of 100-0.2 MHz, and was measured to be a 1.7% change in permittivity across different devices.
| Original language | English |
|---|---|
| Article number | 024305 |
| Journal | Journal of Applied Physics |
| Volume | 99 |
| Issue number | 2 |
| DOIs | |
| State | Published - 15 Jan 2006 |
Bibliographical note
Funding Information:The authors would like to acknowledge the help of Daniele Malleo (visiting research student from the University of Southampton School of Electronics and Computer Science supported by the UK Interdisciplinary Research Centre in Bio-Nanotechnology) in the form of code optimization and helpful discussion, and Hugh Crenshaw, Sudhanshu Gakhar, and Daniel Hartmann from GlaxoSmithKline for important insights. This material is based upon work supported by the National Science Foundation, a Whitaker foundation fellowship, an NDSEG fellowship, as well as funding from GlaxoSmithKline. Two of the authors (C.I.-Z) (J.T.N.) contributed equally.