Three Dimensional Micro/Nano-Patterning of Biomolecules for High Throughput Physiological Sensing
Rapid and real-time evaluation of physiological processes at the molecular level is required for dynamic and complex biological systems. Highly selective and sensitive sensing modalities such as biosensors can be used to obtain simultaneous measurements of cell and tissue transport kinetics under physiologically relevant conditions. However, the widespread applications of biosensors are still challenging due to the limited numbers of facile and reproducible functionalization methods and the limited variety of analyte sensitive molecules for selective recognition. Therefore, here novel biofunctionalization methods have been explored in combination with the most recent generation of recognition biomolecules, specifically genetically encoded molecular sensors and aptamers, in sensing platforms to extend and improve the application of biosensors to physiology. Novel optical sensor functionalization methods were developed based on two approaches: light-induced hydrogel patterning and covalent surface modification of carbon based nanomaterials. In the first approach, optical sensor was constructed by incorporating a member of genetically encoded fluorescent protein biosensors; GCaMP3 into photocurable hydrogel matrix at the distal end of optical fiber through UV light induced polymerization (photopolymerization). Later, this approach was used to develop a miniaturized GCaMP3 doped microoptrodes. In the second functionalization scheme, a graphene oxide nanosheets based covalent aptasensor was developed with better selectivity and higher resistance to nonspecific probes displacement compared to physisorbed ones. The hydrogel formulation and fabrication process demonstrated here using microtip optrodes can be easily adapted to other conformation-dependent protein biosensors and analyte sensitive biomolecules and be used in different sensing applications. The surface modification technique developed here is also a universal and robust functionalization method that can easily be applied to different target molecules simply by changing the aptamer sequence.
Rickus, Purdue University.
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