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Biosensors for detection of Hepatitis markers / FFION WALTERS

Swansea University Author: FFION WALTERS

  • E-Thesis – open access under embargo until: 20th January 2028

DOI (Published version): 10.23889/SUthesis.62669

Abstract

Recently, the miniaturisation of immunoassay platforms has meant an enormous push towards point-of-care (POC) sensor devices. POC sensors have wide applications but are especially beneficial in resource-limited settings. Furthermore, infectious diseases such as hepatitis have become endemic in popul...

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Published: Swansea 2023
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Guy, Owen J.
URI: https://cronfa.swan.ac.uk/Record/cronfa62669
first_indexed 2023-02-15T14:59:29Z
last_indexed 2023-02-16T04:21:06Z
id cronfa62669
recordtype RisThesis
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Although multiple sensor formats have been examined, graphene has emerged as a material to impart the high sensitivity required for POC diagnostics. Affinity biosensors based on a graphene field-effect transistor (GFET) or resistor design utilise graphene&#x2019;s exceptional electrical properties. Therefore, it is critical when designing these sensors that the electrical properties of graphene are maintained throughout the functionalisation process. To that end, noncovalent functionalisation may be preferred over covalent modification. Therefore, graphitic surfaces were functionalised noncovalently via a drop-cast method. Successful modification of graphene with 1,5 Diaminonaphthalene (DAN) via a drop-cast technique was confirmed using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and real-time resistance measurements. Furthermore, an investigation into the effect of sequential wash steps, which are required in biosensor manufacture, confirmed that the functional layer was not removed, even after multiple solvent exposures. Although highly desirable, the high sensitivity of graphene means it is also susceptible to high background signals from the sample media; the signal-to-background ratio can potentially be improved by using signal enhancements. These enhancements may enable the sensitivity needed to provide one-stop diagnosis and commencement of treatment for resource-limited settings. A hybrid biosensor based on a graphene resistor functionalised with self-assembled graphene-AuNPs (Gold Nanoparticles) is demonstrated for the real-time detection of hepatitis B surface antigen (HBsAg). Real-time 2-point resistance measurements, performed using varying concentrations of HBsAg, show a linear dependence of resistance change against the logarithm of HBsAg concentration (log[HBsAg]). A limit of detection of 50 pg ml&#x2212;1 was observed. Moreover, the hybrid biosensor platform has the potential to be applied to any biomarker of interest. Towards the realisation of POC sensors for resource-limited settings and one-stop diagnosis, compatibility of the sensors with fingerstick (FS) sample collection will be highly desirable. A graphene-gold nanoparticle hybrid sensor platform technology is reported in this work that demonstrates the real-time detection of viral proteins utilising low volume samples (5 &#xB5;L). Hepatitis C Virus (HCV) is still an endemic problem worldwide and is used as an example here to demonstrate the platform viral detection sensor technology. Real-time resistance measurements were performed for various concentrations of HCVcAg, showing a linear concentration dependence in the concentration range of 100 -750 pg/mL.</abstract><type>E-Thesis</type><journal/><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher/><placeOfPublication>Swansea</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Biosensors, Hepatitis, Functionalisation, Non-Covalent, Graphene</keywords><publishedDay>20</publishedDay><publishedMonth>1</publishedMonth><publishedYear>2023</publishedYear><publishedDate>2023-01-20</publishedDate><doi>10.23889/SUthesis.62669</doi><url/><notes>ORCiD identifier: https://orcid.org/0000-0003-1732-6886</notes><college>COLLEGE NANME</college><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><supervisor>Guy, Owen J.</supervisor><degreelevel>Doctoral</degreelevel><degreename>Ph.D</degreename><degreesponsorsfunders>KESS II</degreesponsorsfunders><apcterm/><funders/><projectreference/><lastEdited>2023-02-15T16:27:40.8321612</lastEdited><Created>2023-02-15T14:53:41.6201400</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Aerospace, Civil, Electrical, General and Mechanical Engineering - Electronic and Electrical Engineering</level></path><authors><author><firstname>FFION</firstname><surname>WALTERS</surname><order>1</order></author></authors><documents><document><filename>Under embargo</filename><originalFilename>Under embargo</originalFilename><uploaded>2023-02-15T15:46:14.7356407</uploaded><type>Output</type><contentLength>17498194</contentLength><contentType>application/pdf</contentType><version>E-Thesis &#x2013; open access</version><cronfaStatus>true</cronfaStatus><embargoDate>2028-01-20T00:00:00.0000000</embargoDate><documentNotes>Copyright: The author, Ffion A. 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spelling 2023-02-15T16:27:40.8321612 v2 62669 2023-02-15 Biosensors for detection of Hepatitis markers d130dda48ad270054504d2355db5219b FFION WALTERS FFION WALTERS true false 2023-02-15 Recently, the miniaturisation of immunoassay platforms has meant an enormous push towards point-of-care (POC) sensor devices. POC sensors have wide applications but are especially beneficial in resource-limited settings. Furthermore, infectious diseases such as hepatitis have become endemic in populations worldwide. Therefore, there are strong drivers to develop sensitive, cheap and portable diagnostic devices to diagnose such infections. Although multiple sensor formats have been examined, graphene has emerged as a material to impart the high sensitivity required for POC diagnostics. Affinity biosensors based on a graphene field-effect transistor (GFET) or resistor design utilise graphene’s exceptional electrical properties. Therefore, it is critical when designing these sensors that the electrical properties of graphene are maintained throughout the functionalisation process. To that end, noncovalent functionalisation may be preferred over covalent modification. Therefore, graphitic surfaces were functionalised noncovalently via a drop-cast method. Successful modification of graphene with 1,5 Diaminonaphthalene (DAN) via a drop-cast technique was confirmed using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and real-time resistance measurements. Furthermore, an investigation into the effect of sequential wash steps, which are required in biosensor manufacture, confirmed that the functional layer was not removed, even after multiple solvent exposures. Although highly desirable, the high sensitivity of graphene means it is also susceptible to high background signals from the sample media; the signal-to-background ratio can potentially be improved by using signal enhancements. These enhancements may enable the sensitivity needed to provide one-stop diagnosis and commencement of treatment for resource-limited settings. A hybrid biosensor based on a graphene resistor functionalised with self-assembled graphene-AuNPs (Gold Nanoparticles) is demonstrated for the real-time detection of hepatitis B surface antigen (HBsAg). Real-time 2-point resistance measurements, performed using varying concentrations of HBsAg, show a linear dependence of resistance change against the logarithm of HBsAg concentration (log[HBsAg]). A limit of detection of 50 pg ml−1 was observed. Moreover, the hybrid biosensor platform has the potential to be applied to any biomarker of interest. Towards the realisation of POC sensors for resource-limited settings and one-stop diagnosis, compatibility of the sensors with fingerstick (FS) sample collection will be highly desirable. A graphene-gold nanoparticle hybrid sensor platform technology is reported in this work that demonstrates the real-time detection of viral proteins utilising low volume samples (5 µL). Hepatitis C Virus (HCV) is still an endemic problem worldwide and is used as an example here to demonstrate the platform viral detection sensor technology. Real-time resistance measurements were performed for various concentrations of HCVcAg, showing a linear concentration dependence in the concentration range of 100 -750 pg/mL. E-Thesis Swansea Biosensors, Hepatitis, Functionalisation, Non-Covalent, Graphene 20 1 2023 2023-01-20 10.23889/SUthesis.62669 ORCiD identifier: https://orcid.org/0000-0003-1732-6886 COLLEGE NANME COLLEGE CODE Swansea University Guy, Owen J. Doctoral Ph.D KESS II 2023-02-15T16:27:40.8321612 2023-02-15T14:53:41.6201400 Faculty of Science and Engineering School of Aerospace, Civil, Electrical, General and Mechanical Engineering - Electronic and Electrical Engineering FFION WALTERS 1 Under embargo Under embargo 2023-02-15T15:46:14.7356407 Output 17498194 application/pdf E-Thesis – open access true 2028-01-20T00:00:00.0000000 Copyright: The author, Ffion A. Walters, 2023. true eng
title Biosensors for detection of Hepatitis markers
spellingShingle Biosensors for detection of Hepatitis markers
FFION WALTERS
title_short Biosensors for detection of Hepatitis markers
title_full Biosensors for detection of Hepatitis markers
title_fullStr Biosensors for detection of Hepatitis markers
title_full_unstemmed Biosensors for detection of Hepatitis markers
title_sort Biosensors for detection of Hepatitis markers
author_id_str_mv d130dda48ad270054504d2355db5219b
author_id_fullname_str_mv d130dda48ad270054504d2355db5219b_***_FFION WALTERS
author FFION WALTERS
author2 FFION WALTERS
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publishDate 2023
institution Swansea University
doi_str_mv 10.23889/SUthesis.62669
college_str Faculty of Science and Engineering
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hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Aerospace, Civil, Electrical, General and Mechanical Engineering - Electronic and Electrical Engineering{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Aerospace, Civil, Electrical, General and Mechanical Engineering - Electronic and Electrical Engineering
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description Recently, the miniaturisation of immunoassay platforms has meant an enormous push towards point-of-care (POC) sensor devices. POC sensors have wide applications but are especially beneficial in resource-limited settings. Furthermore, infectious diseases such as hepatitis have become endemic in populations worldwide. Therefore, there are strong drivers to develop sensitive, cheap and portable diagnostic devices to diagnose such infections. Although multiple sensor formats have been examined, graphene has emerged as a material to impart the high sensitivity required for POC diagnostics. Affinity biosensors based on a graphene field-effect transistor (GFET) or resistor design utilise graphene’s exceptional electrical properties. Therefore, it is critical when designing these sensors that the electrical properties of graphene are maintained throughout the functionalisation process. To that end, noncovalent functionalisation may be preferred over covalent modification. Therefore, graphitic surfaces were functionalised noncovalently via a drop-cast method. Successful modification of graphene with 1,5 Diaminonaphthalene (DAN) via a drop-cast technique was confirmed using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and real-time resistance measurements. Furthermore, an investigation into the effect of sequential wash steps, which are required in biosensor manufacture, confirmed that the functional layer was not removed, even after multiple solvent exposures. Although highly desirable, the high sensitivity of graphene means it is also susceptible to high background signals from the sample media; the signal-to-background ratio can potentially be improved by using signal enhancements. These enhancements may enable the sensitivity needed to provide one-stop diagnosis and commencement of treatment for resource-limited settings. A hybrid biosensor based on a graphene resistor functionalised with self-assembled graphene-AuNPs (Gold Nanoparticles) is demonstrated for the real-time detection of hepatitis B surface antigen (HBsAg). Real-time 2-point resistance measurements, performed using varying concentrations of HBsAg, show a linear dependence of resistance change against the logarithm of HBsAg concentration (log[HBsAg]). A limit of detection of 50 pg ml−1 was observed. Moreover, the hybrid biosensor platform has the potential to be applied to any biomarker of interest. Towards the realisation of POC sensors for resource-limited settings and one-stop diagnosis, compatibility of the sensors with fingerstick (FS) sample collection will be highly desirable. A graphene-gold nanoparticle hybrid sensor platform technology is reported in this work that demonstrates the real-time detection of viral proteins utilising low volume samples (5 µL). Hepatitis C Virus (HCV) is still an endemic problem worldwide and is used as an example here to demonstrate the platform viral detection sensor technology. Real-time resistance measurements were performed for various concentrations of HCVcAg, showing a linear concentration dependence in the concentration range of 100 -750 pg/mL.
published_date 2023-01-20T05:06:31Z
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score 11.099424

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