Related Experiment Video
Updated: May 25, 2026

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis
Published on: January 6, 2016
Boron δ-doped (111) diamond solution gate field effect transistors
Robert Edgington1, A Rahim Ruslinda, Syunsuke Sato
1London Centre for Nanotechnology, and Department of Electronic and Electrical Engineering, University College London, 17-19 Gordon Street, London, WC1H 0AH, UK.
This study introduces a novel diamond-based biosensor for cell monitoring. The new oxidised boron solution gate field effect transistor (SGFET) offers enhanced performance and stability for detecting cellular electrical activity.
Area of Science:
- Materials Science
- Nanotechnology
- Biophysics
Background:
- Solution gate field effect transistors (SGFETs) are crucial for biosensing applications.
- Diamond-based SGFETs offer excellent biocompatibility and chemical stability.
- Previous diamond SGFETs faced challenges with stability and performance.
Purpose of the Study:
- To present the first oxidised boron δ-doped diamond SGFET.
- To evaluate its performance and characteristics for biosensing.
- To assess its potential for recording cellular action potentials.
Main Methods:
- Fabrication of SGFETs using an optimized plasma chemical vapour deposition (PECVD) for δ-layers on (111) diamond.
- Characterization of current-voltage (I-V) properties and transistor parameters.
- Assessment of pH sensitivity and temporal response using a site-binding model.
Main Results:
- The novel SGFET operates in enhancement mode with channel pinch-off and current saturation.
- Achieved figures of merit (gain: 3, transconductance: 200μS/mm) comparable to hydrogen-based SGFETs.
- Demonstrated a pH sensitivity of 36 mV/pH with fast temporal responses and stability against anodic oxidation.
Conclusions:
- Oxidised boron δ-doped diamond SGFETs exhibit promising performance and enhanced stability.
- These devices are suitable for biosensing and recording action potentials from electrogenic cells.
- The findings pave the way for advanced biocompatible electronic devices for cellular interfaces.
More Related Videos
11:42Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
11:33All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
Related Concept Videos
Field Effect Transistor
Biasing of FET
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the gate...
Bipolar Junction Transistor
The structure...
MOSFET: Enhancement Mode
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no current...
MOSFET: Depletion Mode
The primary characteristic of depletion-mode MOSFETs is their ability to conduct current between the drain and source terminals without gate bias. This inherent conductivity arises...
MOSFET
In an n-MOSFET, the structure includes n-type source and drain...