Coupled Heterogeneous Nanowire鈥揘anoplate Planar Transistor Sensors for Giant (>10 V/pH) Nernst Response
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- 作者：Jonghyun Go ; Pradeep R. Nair ; Bobby Reddy ; Jr. ; Brian Dorvel ; Rashid Bashir ; Muhammad A. Alam
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：July 24, 2012
- 年：2012
- 卷：6
- 期：7
- 页码：5972-5979
- 全文大小：498K
- 年卷期：v.6,no.7(July 24, 2012)
- ISSN：1936-086X
文摘
We offer a comprehensive theory of pH response of a coupled ISFET sensor to show that the maximum achievable response is given by 螖V/螖pH = 59 mV/pH 脳 伪, where 59 mV/pH is the intrinsic Nernst response and 伪 an amplification factor that depends on the geometrical and electrical properties of the sensor and transducer nodes. While the intrinsic Nernst response of an electrolyte/site-binding interface is fundamental and immutable, we show that by using channels of different materials, areas, and bias conditions, the extrinsic sensor response can be increased dramatically beyond the Nernst limit. We validate the theory by measuring the pH response of a Si nanowire鈥搉anoplate transistor pair that achieves >10 V/pH response and show the potential of the scheme to achieve (asymptotically) the theoretical lower limit of signal-to-noise ratio for a given configuration. We suggest the possibility of an even larger pH response based on recent trends in heterogeneous integration on the Si platform.