Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor

Escherichia coli (E. coli) bacteria comes from the human and animal faeces. It is hazardous to human health and could cause death when not immediately treated. Therefore, it is crucial to detect E. coli bacteria in water before consuming it. Since many cases of water contaminated E. coli bacter...

Full description

Saved in:

Bibliographic Details
Main Author:	Md Rosni, Nurliyana
Format:	Thesis
Language:	English English English
Published:	2020
Subjects:	QR Microbiology
Online Access:	http://eprints.uthm.edu.my/1124/1/24p%20NURLIYANA%20MD%20ROSNI.pdf http://eprints.uthm.edu.my/1124/2/NURLIYANA%20MD%20ROSNI%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/1124/3/NURLIYANANTI%20MD%20ROSNI%20WATERMARK.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-uthm-ep.1124
record_format	uketd_dc
spelling	my-uthm-ep.11242021-09-30T02:07:32Z Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor 2020-08 Md Rosni, Nurliyana QR Microbiology Escherichia coli (E. coli) bacteria comes from the human and animal faeces. It is hazardous to human health and could cause death when not immediately treated. Therefore, it is crucial to detect E. coli bacteria in water before consuming it. Since many cases of water contaminated E. coli bacteria are in rural areas, a portable E. coli bacteria detector is needed. However, many existing biosensors to detect E. coli bacteria are not portable, while the conventional methods are time-consuming and need specialists to perform the task. In this work, an E. coli bacteria biosensor based on the resistivity method was developed using graphene nanostructure as the sensing layer, since carbon materials such as graphene have been known to have biocompatibility and excellent electrical properties. As a result, the concentration of E. coli bacteria can be measured through the change of conductivity caused by the negative charge produced by the E. coli bacteria’s surface. Anti-E. coli antibodies and a blocking agent were employed on the graphene’s surface for selectivity purposes. Characterisations using FESEM, AFM, Raman spectroscopy and contact angle were successfully conducted to study the properties and to verify the presence of the immunosensing properties on the sensing layer. The full system was developed with a standalone user interface and does not require any alternating current (AC) outlet or personal computer (PC) connection. An Arduino microcontroller was used to operate the new device. The circuit was functionalised to detect resistance change with the help of Wheatstone bridge for device calibration. Results show that resistivity change that can be detected by the device was as low as 0.0426 Ω. For E. coli bacteria detection, the system has a linear relationship between the device reading and the concentration of E. coli bacteria. The conductivity of Graphene increased with the increasing of E. coli bacteria concentration. Finally, the validation of the device was performed by comparing the data obtained from the device with plate culture method. The device was found to detect the concentration of E. coli bacteria selectively with LOD between 145 CFU/ml to 7966 CFU/ml with 104 seconds detection time. 2020-08 Thesis http://eprints.uthm.edu.my/1124/ http://eprints.uthm.edu.my/1124/1/24p%20NURLIYANA%20MD%20ROSNI.pdf text en public http://eprints.uthm.edu.my/1124/2/NURLIYANA%20MD%20ROSNI%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/1124/3/NURLIYANANTI%20MD%20ROSNI%20WATERMARK.pdf text en validuser mphil masters Universiti Tun Hussein Onn Malaysia Fakulti Kejuruteraan Elektrik dan Elektronik
institution	Universiti Tun Hussein Onn Malaysia
collection	UTHM Institutional Repository
language	English English English
topic	QR Microbiology
spellingShingle	QR Microbiology Md Rosni, Nurliyana Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
description	Escherichia coli (E. coli) bacteria comes from the human and animal faeces. It is hazardous to human health and could cause death when not immediately treated. Therefore, it is crucial to detect E. coli bacteria in water before consuming it. Since many cases of water contaminated E. coli bacteria are in rural areas, a portable E. coli bacteria detector is needed. However, many existing biosensors to detect E. coli bacteria are not portable, while the conventional methods are time-consuming and need specialists to perform the task. In this work, an E. coli bacteria biosensor based on the resistivity method was developed using graphene nanostructure as the sensing layer, since carbon materials such as graphene have been known to have biocompatibility and excellent electrical properties. As a result, the concentration of E. coli bacteria can be measured through the change of conductivity caused by the negative charge produced by the E. coli bacteria’s surface. Anti-E. coli antibodies and a blocking agent were employed on the graphene’s surface for selectivity purposes. Characterisations using FESEM, AFM, Raman spectroscopy and contact angle were successfully conducted to study the properties and to verify the presence of the immunosensing properties on the sensing layer. The full system was developed with a standalone user interface and does not require any alternating current (AC) outlet or personal computer (PC) connection. An Arduino microcontroller was used to operate the new device. The circuit was functionalised to detect resistance change with the help of Wheatstone bridge for device calibration. Results show that resistivity change that can be detected by the device was as low as 0.0426 Ω. For E. coli bacteria detection, the system has a linear relationship between the device reading and the concentration of E. coli bacteria. The conductivity of Graphene increased with the increasing of E. coli bacteria concentration. Finally, the validation of the device was performed by comparing the data obtained from the device with plate culture method. The device was found to detect the concentration of E. coli bacteria selectively with LOD between 145 CFU/ml to 7966 CFU/ml with 104 seconds detection time.
format	Thesis
qualification_name	Master of Philosophy (M.Phil.)
qualification_level	Master's degree
author	Md Rosni, Nurliyana
author_facet	Md Rosni, Nurliyana
author_sort	Md Rosni, Nurliyana
title	Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
title_short	Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
title_full	Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
title_fullStr	Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
title_full_unstemmed	Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
title_sort	development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor
granting_institution	Universiti Tun Hussein Onn Malaysia
granting_department	Fakulti Kejuruteraan Elektrik dan Elektronik
publishDate	2020
url	http://eprints.uthm.edu.my/1124/1/24p%20NURLIYANA%20MD%20ROSNI.pdf http://eprints.uthm.edu.my/1124/2/NURLIYANA%20MD%20ROSNI%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/1124/3/NURLIYANANTI%20MD%20ROSNI%20WATERMARK.pdf
_version_	1747830741985656832

Development of portable escherichia coli bacteria detection using resistive graphene-based immunosensor

Similar Items