E-Thesis 45 views 29 downloads
Graphene-Based Electronic Sensors for Gas Detection / DANIELLE GOODWIN
Swansea University Author: DANIELLE GOODWIN
DOI (Published version): 10.23889/SUThesis.69048
Abstract
This thesis describes the development of graphene-based sensor arrays, focusing on signal enhancement through innovative surface modification techniques, whilst leveraging graphene's unique properties. Awareness of the dangers posed by toxic gases has increased the demand for advanced gas senso...
| Published: |
Swansea University, Wales, UK
2025
|
|---|---|
| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | EngD |
| Supervisor: | Guy, O., J., and Carta, M. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69048 |
| Abstract: |
This thesis describes the development of graphene-based sensor arrays, focusing on signal enhancement through innovative surface modification techniques, whilst leveraging graphene's unique properties. Awareness of the dangers posed by toxic gases has increased the demand for advanced gas sensors, which are critical for monitoring harmful gases. Gas sensor arrays, or "electronic noses," offer advantages over single sensors, including the ability to detect multiple analytes simultaneously with greater accuracy.Since its discovery in 2004, graphene has attracted significant interest due to its exceptional mechanical, chemical, and electrical properties, which make it ideal for miniaturized, low-cost sensors with high sensitivity and selectivity. However, graphene's high sensitivity poses a challenge, as it interacts with a wide range of molecules. Managing this sensitivity and selectivity through advanced surface modification techniques is crucial for enhancing the performance of graphene-based sensors.In this thesis, various surface modification techniques were explored to enhance the selectivity and sensitivity of graphene-based sensors, specifically targeting the detection of nitrogen dioxide, ammonia, nitric oxide, methane, and carbon dioxide. These modifications aimed to improve sensor selectivity while maintaining a strong response. One notable technique involved integrating metal phthalocyanines, known for their gas sensitivity, with graphene to create a hybrid sensor. For instance, a graphene sensor functionalized with tetra-tert-butyl copper phthalocyanine was developed for real-time detection of nitrogen dioxide (NO2), achieving a linear response and a detection limit of 31 ppb, showcasing its potential as a highly selective and effective NO2 detector.Polymers of intrinsic microporosity (PIMs), although well-established in gas separation, have not been extensively explored for gas sensing. This thesis presents a PIM-modified graphene sensor array that demonstrated high selectivity and sensitivity towards NO2, with a detection limit of 0.7 ppb, indicating its suitability for highly sensitive NO2 detection.The development of the graphene sensor array began with exploring electrochemical functionalization across different pixels, allowing each graphene element to respond to the same gas with different magnitudes. This proof-of-concept array demonstrated that these distinct responses could potentially be integrated with pattern recognition software to identify unknown gases. Beyond detecting environmental gases, the graphene sensors can also be adapted for the detection of volatile organic compounds(VOCs).To test the arrays, a gas sensing system was developed to enable simultaneous, real- time resistance measurements for each graphene pixel. The iterative development of this system is reported, highlighting challenges and limitations.A proof-of-concept bioelectronic nose based on a graphene resistor has been fabricated and evaluated. Functionalized with 1,5-diaminonaphthalene and immobilized with human olfactory receptor 2AG1, it selectively detected amyl butyrate at 0.5 pM, indicating the potential of bioelectronic noses using olfactory receptors, which can recognize multiple VOCs, thus reducing the required number of sensors in an array. |
|---|---|
| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
graphene, gas sensing, functionalization, electronic sensor, semiconductor |
| College: |
Faculty of Science and Engineering |
| Funders: |
COATED M2A funding from the European Social Fund via the Welsh Government (c80816), The Engineering and Physical Sciences Research Council (Grant Ref: EP/S02252X/1) |