Construction of nanobiosensors for detection of biomarkers
Other Title(s)
بناء متحسسات حيوية نانوية للكشف عن المؤشرات الحيوية
Dissertant
Thesis advisor
al-Qazzaz, Abd al-Karim Abd al-Razzaq Abd al-Wahhab
Melconian, Alice Krikor
Comitee Members
Aziz, Ghazi Munim
al-Haddad, Rad Muhammad Salih
Fadil, Iyad Muhammad Ali
Adhiah, Ali Husayn
Ahmad, Ali Shihab
University
University of Baghdad
Faculty
College of Science
Department
Biotechnology Department
University Country
Iraq
Degree
Ph.D.
Degree Date
2013
English Abstract
The present study was designed to detect both CA125 and glucose biomarkers by using nanoparticles based sensor.
An enzyme-linked immunoassay based on dual signal detection has been developed for the detection of ovarian cancer biomarker CA125.
The sandwich-type immunoassays use nanoelectrode array (NEA) chip and absorbance methods for the dual detection.
The NEA is used to confirm the optical detection of CA125 that was carried out in a high-binding 96-well plate.
An alkaline phosphatase (AP) enzyme was used to label the detection antibody to allow both the optical and electrochemical identification.
Two kinds of substrates were catalyzed by the AP enzyme.
Para-nitrophenylphosphate (PNPP) produces chromogenic para-nitrophenol (PNP), which can be optically detected at 405 nm.
Para-aminophenylphosphate (PAPP) produces electroactive para-aminophenol (PAP), which can be detected amperometrically between -0.1 to 0.3 V.
The linear range has been determined to be 5-1000 U/ml for both the optical and electrochemical immunoassays.
The limit of detection (LOD) of the optical immunoassay was determined to be 1.3 U/ml and for the NEA amperometry was 40 U/ml.
The low LOD for both transduction methods are promising for early stage detection of cancer through CA125 which has a physiological level at 35 U/ml.
For analytical glucose determination a surface enhanced Raman spectroscopy (SERS) coupling with GOx-catalyzed oxidation of glucose were applied to evaluate glucose concentration by measuring Raman intensity for hydrogen peroxide (H2O2) that produced from glucose oxidation by GOx enzyme.
Under optimized conditions the calibration curve was established.
The linear regression curve was plotted using y = 1575x + 1109 with very good correlation (R2 = 0.97 ) , recorded after 10 min .Besides, the limit of detection (LOD) was 0.278 mM.
The reliability of the sensor was confirmed with the most important interferences in blood ascorbic acid (AA) and uric acid (UA), the assay did not show any interference with the desired signal.
Ultimately, saliva was used as analytical fluid to sense concentration of glucose instead of using finger prick.
Application of saliva for detecting glucose revealed promising results with more comfortable way for patients.
Main Subjects
No. of Pages
106
Table of Contents
Table of contents.
Abstract.
Abstract in Arabic.
Introduction.
Chapter One : Literature review.
Chapter Two : Materials and methods.
Chapter Three : Results and discussions.
Conclusions and recommendations.
References.
American Psychological Association (APA)
al-Aqaidi, Isra Ali Zaydan. (2013). Construction of nanobiosensors for detection of biomarkers. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad, Iraq
https://search.emarefa.net/detail/BIM-601381
Modern Language Association (MLA)
al-Aqaidi, Isra Ali Zaydan. Construction of nanobiosensors for detection of biomarkers. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad. (2013).
https://search.emarefa.net/detail/BIM-601381
American Medical Association (AMA)
al-Aqaidi, Isra Ali Zaydan. (2013). Construction of nanobiosensors for detection of biomarkers. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad, Iraq
https://search.emarefa.net/detail/BIM-601381
Language
English
Data Type
Arab Theses
Record ID
BIM-601381
