Physics and simulation of nanoscale bio- and chemical sensors
Abstract
The ability to detect biomolecules and chemicals accurately, effectively, and promptly in variety of environments including applications in homeland security, clinical diagnoses, environmental monitoring, food safety, etc. has always been an important issue. For each of these applications, it is highly desirable that a small, ultra-sensitive, versatile and robust sensor be created. During the last decade, enormous progress in the synthesis of 1-D nanostructured materials and nanoparticles has allowed the fabrication of nanometer-sized sensors. Such materials and devices, with large surface-to-volume ratios and Debye length comparable to their small size, have already displayed superior sensitivity for the detection of various chemical and biological species. Their extremely small-scale also enables the miniaturization of sensors (e.g., portable, handheld sensors) as well as their multiplexing functionality to achieve simultaneous detection of multiple target molecules in a given sample. In spite of huge existing research regarding the fabrication of nanoscale bio- and chemical sensors, the understanding of their sensing mechanism has been limited, confused, and contradictory. In this thesis, we develop a comprehensive theoretical framework to correlate the geometry and physical properties of nanoscale sensors to their sensing performance of target molecules. This framework provides the solution for the puzzles arising from the discrepancy in recent experimental results and the classical theory regarding sensor performance and give guidance for approaches about the sensor design and optimization.
Degree
Ph.D.
Advisors
Alam, Purdue University.
Subject Area
Electrical engineering
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