Browsing by Subject "nanophotonics"

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Open Access
Design and development of novel large scale applications in micro/nanophotonics and nanobiotechnology
(2014) Özgür, Erol
Developments in micro/nanophotonics and nanobiotechnology creates new opportunities regarding development of devices with unprecedented capabilities, which could improve human civilization substantially. On the other hand, a certain level of maturity in transforming these possibilities into reality still requires considerable efforts. One of the main problems of these novel technologies is that their practical know-how is so scarce that they could only be utilized within strictly determined laboratory conditions, and by highly sophisticated scientists. This thesis focuses on large scale applications at the intersection of microphotonics and nanobiotechnology, and also in nanophotonics. On microphotonics side, optical microresonators with toroidal shape were successfully fabricated and optically integrated. Having an extremely high sensitivity towards perturbations in their environments, these microcavities could be used as biological sensors; however, they are also very sensitive for nonspecific interactions. Thus, a novel surface chemistry enabling bioconjugation of molecular probes without compromising their sensitivity and enhancing their selectivity was developed, based on methylphosphonate containing silane modification of the microtoroid surface. After this functionalization, microtoroids were used in biodetection in complex media. Also, a macroscopic photodetection device composed on intrinsically aligned semiconducting selenium nanowires were demonstrated. This device could be considered as a novel and efficient demonstration of nanowire integration to the macroscopic world. Together with the research on biosensors, these are important large scale applications of emergent science of our age.
Open Access
Targeted self-assembly of nanocrystal quantum dot emitters using smart peptide linkers on light emitting diodes
(2008) Zengin, Gülis
Semiconductor nanocrystal quantum dots find several applications in nanotechnology. Particularly in device applications, such quantum dots are typically required to be assembled with specific distribution in space for enhanced functionality and placed at desired spatial locations on the device which commonly has several diverse material components. In conventional approaches, self-assembly of nanocrystals typically takes place nonspecifically without surface recognition of materials and cannot meet these requirements. To remedy these issues, we proposed and demonstrated uniform, controlled, and targeted self-assembly of quantum dot emitters on multi-material devices by using cross-specificity of genetically engineered peptides as smart linkers and achieved directed immobilization of these quantum dot emitters decorated with peptides only on the targeted specific regions of our color-conversion LEDs. Our peptide decorated quantum dots exhibited 270 times stronger photoluminescence intensity compared to their negative control groups.