Date of Award


Degree Name

Master of Science



First Advisor

Poopalasingam, Sivakumar


Epithelial ovarian cancer is the fifth leading cause of cancer-related deaths in the United States. However, the mortality rate is relatively high, due to in part to the cancer being in an advance stage at diagnosis, since it is often asymptomatic at the early-stage with a ~94% of five-year survival rate if it is diagnosed at a localized stage (stage 1). Early detection of cancer would likely improve the survival rate. Scientists are searching for novel promising methods to detect ovarian cancer at an asymptomatic early stage; also, the method is cheap and user-friendly despite there are various techniques for ovarian cancer detection. Cancer antigen 125 (CA125), a type of serum biomarker that elevates ~50% of women with early-stage and ~80% of women with advanced-stage, is used mostly for screening epithelial ovarian cancer. However, the lack of sensitivity and specificity are known to be the main drawback of CA125. Finding new potential biomarkers that diagnose cancer at a localized stage will significantly reduce the mortality rate. Human epididymis protein 4 (HE4) is such a biomarker that has a higher sensitivity and specificity compared to all other known biomarkers, and recently it has been approved by food and drug administration (FDA) for clinical applications.In this project, we developed sandwich-type micro particles immunoassay for sensitive detection of HE4 biomarker in plasma. Here, we cross-link elemental particles to a specific functional group of the targeted biomolecules based on a covalent and non-covalent linking chemistry to improve the sensitivity and the selectivity of biomarker detection in which Fe3O4 and SiO2 microparticles were used to conjugate and purify the antibody-antigen in a media. The purified assay with the microparticles was analyzed with laser-induced breakdown spectroscopy (LIBS) for detection and quantization analysis of the HE4 biomarker. Furthermore, along with LIBS, Raman, Fourier transform infrared (FT-IR), and UV- Vis spectroscopic techniques were utilized to understand the conjugation dynamic and confirm the conjugation process.




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