Announcing the Final Examination of Ms. Weiwei Gao for the degree of Doctor of Philosophy
Platinum-group metal (PGM) nanostructures with peroxidase-like activities (i.e., peroxidase mimics) are widely used as signal transducers in biosensing applications. For instance, they are used to establish enzyme-linked immunosorbent assays (ELISAs) for the detection of protein-, peptide- and hormone-based biomarkers in clinical samples. In biosensing applications, PGM peroxidase mimics act as catalysts to speed up certain chemical reactions that generate color signal. Compared to natural peroxidase, PGM peroxidase mimics are more catalytically efficient, providing stronger color signal and thus a lower limit of detection (LOD). The performance of PGM peroxidase mimics in biosensing applications is largely determined by their catalytic activity, which can be tuned and optimized by controlling their physicochemical parameters such as size, shape, elemental composition and surface ligand. In this thesis work, we have developed a series of PGM peroxidase mimics with well-controlled physicochemical parameters and applied them to biosensing applications. In one study, for example, we have designed and synthesized Ir, Pt and Ir/Pt alloyed nanowires as peroxidase mimics and applied them to detection of carcinoembryonic antigen (CEA, a cancer biomarker). In another study, we developed ultrasmall Ir nanoparticles as efficient peroxidase mimics for sensitive detection of CEA and aflatoxin B1 (a carcinogenic toxin). In addition to applied research, we have performed fundamental studies to better understand PGM peroxidase mimics. For instance, we have investigated the size effect in peroxidase mimics by using Pd-Ir core-shell nanoparticles as a model system.
Committee in Charge:
Dr. Xiaohu Xia (chair)
Dr. Yulia Gerasimova
Dr. Shengli Zou
Dr. Gang Chen
Dr. Xiaofeng Feng
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