Applications of carbon nanotubes in bioanalytical chemistry research

This dissertation focuses on the interface and study of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) with biology. The goal was to take advantage of the nanostructure of CNTs and CNFs for unconventional biomolecular studies requiring ultrahigh sensitivity, resolution, high-degree of miniaturization, and selective biofunctionalization. In this dissertation, CNFs were utilized as ultramicroelectrodes for novel biomolecule sensing and cell penetrating platforms, CNTs were utilized as high resolution atomic force microscopy (AFM) imaging probes for cell morphology investigations and CNTs were utilized to generate a platform by which to evaluate nanomaterial phytotoxicity.;CNF arrays were utilized for ultrahigh sensitivity sensing and cell penetration platforms. Arrays of CNFs harness the advantages of an individual CNF as well the collective property of assemblies, which made them promising materials in biosensing and tissue engineering or implantation. Two CNF platforms were demonstrated. One platform exploited the CNF's nanoscale and strong conductance as ultramicroelectrodes for biomolecule sensing applications. The other platform made use of CNF's high aspect ratio structure to be an array of needle-like electrodes that support PC-12 cell growth and penetrated through the cell membrane. The goal was to take advantage of the nanostructure of CNFs for biomolecule detection and cell interfacing studies.;CNT AFM probes were utilized for morphological characterization of fixed rat basophilic lymphocyte (RBL) cells. CNT AFM probes offer advantages in the visualization of cellular membrane morphology. Due to the inherent high aspect ratio geometry, CNT AFM probes were able to resolve unique membrane features, such as lamelopodia, filopodia and microvilli, of a spreading RBL cell where standard silicon probes could not. The structures resolved by the CNT probes are crucial to characterize cellular events such as spreading, locomotion, activation and differentiation. This work represented the first time that whole cells have been imaged with CNT tips and help the AFM gain acceptance in cellular biology.;Finally, loose CNTs and alumina nanoparticles were utilized to explore the environmental consequences of engineered nanomaterials. A simple platform, based on two different plant species, was developed and used to expose undergraduate researchers to nanoscience. Nanomaterial phytotoxicity was quantified by the number of seed germinations and length of plant shoots. It was determined that solubilized CNT nanomaterials have increased phytotoxic effects compared to solutions containing nanomaterial agglomerates. This study gave insight into the importance of nanomaterial presentation to the phytotoxic response.;These studies provided insight to biological systems that was not possible using traditional approaches and represents great promise for the future use of nanomaterials in bioanalytical chemistry research.