Miniaturized Analytical Platforms From Nanoparticle Components: Studies in the Construction, Characterization, and High-Throughput Usage of These Novel Architectures

Abstract

The scientific community has recently experienced an overall effort to reduce the physical size of many experimental components to the nanometer size range. This size is unique as the characteristics of this regime involve aspects of pure physics, biology, and chemistry. One extensively studied example of a nanometer sized experimental component, which acts as a junction between these three principle scientific theologies, is deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). These biopolymers not only contain the biological genetic guide to code for the production of life-sustaining materials, but are also being probed by physicists as a means to create electrical circuits and furthermore as controllable architectural and sensor motifs in the chemical disciplines. Possibly the most common nano-sized component between these sciences are nanoparticles composed of a variety of materials. The cross discipline employment of nanoparticles is evident from the vast amount of literature that has been produced from each of the individual communities within the last decade. Along these cross-discipline lines, this dissertation examines the use of several different types of nanoparticles with a wide array of surface chemistries to understand their adsorption properties and to construct unique miniaturized analytical and immunoassay platforms. This introduction will act as a literature review to provide key information regarding the synthesis and surface chemistries of several types of nanoparticles. This material will set the stage for a discussion of assembling ordered arrays of nanoparticles into functional platforms, architectures, and sensors. The introduction will also include a short explanation of the atomic force microscope that is used throughout the thesis to characterize the nanoparticle-based structures. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 examines the self-assembly of polymeric nanoparticles exhibiting a variety of surface chemistries and attempts to deconvolute general adsorption rules for their assembly on various substrates. Chapter 2 extends the usage of self-assembly of polymeric nanoparticles through a layer-by-layer deposition concept and photolithography methodologies to create analytical platforms with a vertical height controlled within the nanometer regime. This platform is then furthered in Chapter 3 by employing this integrated concept as a bio-recognition platform, with the extension of the method to a high-throughput screening system explored. Chapter 4 exploits two different types of nanoparticles, silica and gold, as multiplexed, self-assembled immunoassay sensors. This final research chapter is followed by a general summation and future prospectus section that concludes the dissertation.