title: Study of parasitic resistance effects in nanowire and nanoribbon biosensors.
abstract: In this work, we investigate sensor design approaches for eliminating the effects of parasitic resistance in nanowire and nanoribbon biosensors. Measurements of pH with polysilicon nanoribbon biosensors are used to demonstrate a reduction in sensitivity as the sensor length is reduced. The sensitivity (normalised conductance change) is reduced from 11% to 5.5% for a pH change from 9 to 3 as the sensing window length is reduced from 51 to 11 μm. These results are interpreted using a simple empirical model, which is also used to demonstrate how the sensitivity degradation can be alleviated by a suitable choice of sensor window length. Furthermore, a differential sensor design is proposed that eliminates the detrimental effects of parasitic resistance. Measurements on the differential sensor give a sensitivity of 15%, which is in good agreement with the predicted maximum sensitivity obtained from modeling.
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Ioannis
authors: I
authors: Zeimpekis
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Kai
authors: K
authors: Sun
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Chunxiao
authors: C
authors: Hu
authors: Oxford Instruments Plasma Technology, Yatton, Bristol, BS49 4AP UK.
authors: Owain
authors: O
authors: Thomas
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Maurits Rr
authors: MR
authors: de Planque
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Harold Mh
authors: HM
authors: Chong
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Hywel
authors: H
authors: Morgan
authors: Zepler Institute, School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ UK.
authors: Peter
authors: P
authors: Ashburn
keywords: Biosensor; Differential biosensor; Nanoribbon; Nanowire; Parasitic resistance; pH sensor