Solid-state nanopore and nanostructure for biomolecule detection

Abstract

In this thesis, we present the main aspects involved in the small molecule detection based on the nanotechnology - nanopore, carbon nanotube Field-effect Transistors (CNT-FETs), and the Giant Magnetoresitance (GMR) device using ferromagnetic nanowire heterostructures. The first part of this thesis deals with the nanotechnology, DNA, proteins, nanopores, ions, and much more. In that chapter, we first zoom in on the nanoscale and describe the biological context for the experimental work described here. Part of this thesis is devoted to the studying aspects of bare λ- and ladder DNA both for example, how the effective charge of DNA is affected by the presence of various ions. This sensor, known as a solid-state nanopore, consists of a tiny hole that is drilled in a thin solid material with a focused electron beam. Another part of this thesis is devoted to the development of a biosensor for protein and DNA modified Au nanoparticles using nanocapillary, designed for ease of fabrication, a novel type of nanopore alternatives, fabricated by heating and pulling the crystal or amorphorous SiO2 tube. The sane electrophoretic events were observed for various molecules, and the series of experimental, theoretical approaches applied for solid-state nanopore were applicable with this platform, confirming the availability of nanocapillary instruments. In the middle part of this thesis, another nanostructure , known as CNT, was exploited for gas molecule detection and it was shown that how this interacts with various molecules electrically, resulting in concentration determination, explained with typical FET scheme, where gas molecules act as gate field source and CNT corresponds to p-type semiconducting channel. Lastly, nanowire type structure was fabricated for GMR effect, where ferromagnetic heterostructure was grown electrochemically inside the Anodized Aluminum Oxide (AAO) template, exhibiting robustness of application with nanostructures. We finish with a brief overview of the contents of each chapter of this thesis.