Development of nanoparticle-modified sensor platform for cancer marker detection

Official URL: http://192.168.1.20/record=b1416922 (Table of Contents)

The detection and quantification of cancer biomarkers in human blood is crucial to diagnose patients in the early stage of a disease. The recent advances in biosensor technology can improve detection by reducing the application time and cost without an invasive approach. The development of such detection system is a major thrust of the rapidly growing biotechnology industry. It involves a multidisciplinary research effort including chemical engineering, microelectronics and biology. This study focused on the development of nanomaterial-modified sensing platform to enhance the sensitivity for cancer marker detection. An electrochemical-based capacitive biosensor was aimed to develop using two alternative nanomaterial modification including gold nanoparticles (Au-NPs) and magnetic beads (MBs) in cancer detection for the first time. Surface Plasmon resonanse (SPR) and quartz crystal microbalance (QCM)-based sensors were initially employed to verify the bioassays and the surface chemistries. The successful achievement of these research works was transferred into an electrochemical based-capacitive biosensor to increase the sensitivity and reliability of the assays for the quantification of the biological markers. The optimized sensor methods were conducted in the capacitive sensor using standard methodologies and the detection limit was increased 6 fold without a signal amplification tool. However, the quantification of some biomarkers is difficult since they have trace threshold level in human blood and/or small size. Moreover, real patient samples include various biological molecules beside the target analyte and this makes the detection difficult due to the non-specific responses and requires the signal amplification. Due to these reasons, a novel nanoparticle modified capacitive sensor was developed and used for synchronous multiple marker detection for the first time. The developed sensor increased the sensitivity up to 600 fold (5 pg.mL-1) when compared with standard sensor assays. The results have provided alternative and effective quantification approaches to the current tools; and also a promising future for precise detection of the cancer types using multiple marker assays. The developed and improved methodologies/sensors in this thesis can also be applied for the other diseases that have biomarkers in human body.