Work

On the origin of enhanced sensitivity in nanoscale FET-based biosensors

Year: 2014

Type: article

Abstract: Electrostatic counter ion screening is a phenomenon that is detrimental to the sensitivity of charge detection in electrolytic environments, such as in field-effect transistor-based biosensors. Using simple analytical arguments, we show that electrostatic screening is weaker in the vicinity of concave curved surfaces, and stronger in the vicinity of convex surfaces. We use this insight to show, using numerical simulations, that the enhanced sensitivity observed in nanoscale biosensors is due to binding of biomolecules in concave corners where screening is reduced. We show that the traditional argument, that increased surface area-to-volume ratio for nanoscale sensors is responsible for their increased sensitivity, is incorrect.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.1315485111

Authors: Kaveh Shoorideh, Chi On Chui

Institutions: California NanoSystems Institute, University of California, Los Angeles

Language: English

Topic: Electrostatics and Colloid Interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: bronze

Funder: National Science Foundation

Award: Nanowire FET Sensors with Intrinsic Sensitivity Improvement