| The application of nanotechnology and nanoparticles, in particular towards biomedical challenges, has evolved greatly over the last 15 years. Nanoparticles have gained popularity due to the unique physical properties (e.g., size-tunable fluorescence in semiconductor quantum dots, surface plasmon resonance in metallic nanoparticles and superparamagnetism in single-domain magnetic nanoparticles) that emerge due to quantum mechanical effects manifested only at the nanoscale. The small size of nanoparticles (typically less than 100nm) also lends to their importance in the bio-medical fields as they are of the same dimension as biological macromolecules, such as proteins and nucleic acids, or organic macromolecular structures, such as polymers.;In this doctoral work, we investigate and harness the interaction between nanoparticles and polymers to solubilize, stabilize and functionalize nanoparticles and then, engineer larger multi-nanoparticle structures. The marriage of the useful physical properties of nanoparticles with the ability to form more complex structures via interaction with polymers enabled the synthesis of multifunctional nano- and micro-scale detection probes aimed at advancing medical diagnostics. Synthetically, we developed epitaxial growth, emulsion and microfluidic based techniques to produce polymeric reporter probes incorporating 100s-millions of fluorescent quantum dots, exhibiting high sensitivity (detectable on single-bead level), stability (chemical) and multiplexing capability (physically and spectrally uniform). Finally, A novel rapid two-bead sandwich assay was developed capable of the discrimination of true positive from false positive signals in homogeneous solution. Finally, these reporter probes were implemented in the two-bead sandwich assay for the ultrasensitive and multiplexed detection of cancer antigens, oligonucleotides, viruses and bacteria. |
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