| Detection of biological species is central to many areas of biology and life sciences such as ultra sensitive disease detection, biochemical sensing and targeted drug delivery. Currently, detection of biomolecules like proteins and DNA is done by fluorescence detection, however, enhancing detection sensitivity and increasing signal to noise ratio still remains a major challenge. Novel techniques are presently required which can provide reliable, low cost, and ultra-sensitive detection of proteins and DNA. This thesis will focus on two approaches in this context: the use of diblock copolymer templates and zinc oxide nanorods, with an aim to provide rapid, sensitive and accurate biomolecular detection. While complementary, these approaches are not necessarily interlinked.;First approach will focus on utilizing the microphase separation behavior of diblock copolymers to pattern proteins with nanometer periodicity. The structural variety and chemical heterogeneity of polystyrene-block-poly(methylmethacrylate) (PS-b-PMMA) and polystyrene-b-poly(4-vinylpyridine) (PS-b-PVP) template surfaces were successfully exploited to spontaneous formation of self-assembled, linear and hexagonally-ordered protein arrays that exhibit repeat spacings in a nanoscopic dimension. More importantly, protein molecules on the polymeric templates maintained their natural conformation and activity for several months. Our results demonstrate that self-assembling, chemically heterogeneous, diblock copolymer templates can be used as excellent, high payload, high density protein templates making them highly suitable as functional substrates in many proteomics applications.;Second approach will focus on the remarkably enhanced optical detection of DNA and proteins which is enabled by the use of nanoscale zinc oxide platforms. Using model protein and nucleic acid systems, we demonstrate that engineered nanoscale zinc oxide nanostructures can significantly enhance the detection capability of biomolecular fluorescence. Without any chemical or biological amplification processes, nanoscale zinc oxide platforms enabled increased fluorescence detection of these biomolecules when compared to other commonly used substrates such as glass, quartz, polymer, and silicon. We also demonstrate the easy integration potential of zinc oxide nanostructures into periodically patterned platforms which, in turn, will promote the assembly and fabrication of these materials into multiplexed, high-throughput, optical sensor arrays. |
