The general theme of this dissertation is the development of new analytical sensors to quantitatively study biological and environmental samples in aqueous and non-aqueous environments. A platinum ultramicroelectrode (UME) and a unique carbon-based pH microprobe were used to design a new SECM-based electrochemical bioassay. The Pt UME was used to...
The detection of biomolecules is critical for clinical diagnostics but requires specialty labor and high cost. The use of microfluidic paper-based analytical devices (µPADs) for bioassays is simpler and cheaper but has low sensitivity. Improved immobilization of antibodies onto cellulose is demonstrated through surface functionalization with APTES and glutaraldehyde. The...
Femtosecond stimulated Raman spectroscopy (FSRS) is a powerful ultrafast technique which can track photoinduced excited state structural events on femtosecond (fs) to picosecond (ps) timescales. In addition to high temporal and spectral resolutions, FSRS provides a broad spectral window from ca. 100—2000 cm-1 for detection, enabling the direct mapping of...
Low-dimensional electronic materials offer a platform to observe biological processes with unprecedented spatial and temporal resolution. Carbon nanotubes (CNTs) are the closest physical analog to an ideal 1D system and can be scaled and integrated into multiplexed electronic circuitry. The molecular structure of a CNT is also biocompatible, making them...
Immobilized proteins are integral components of a number of important technologies, including the principal component of many biosensors, as functional coatings in various implants, as catalysts is industrial biosynthesis, and as the building blocks of next-generation nanotechnologies. Despite their ubiquity, relatively little is known about the processes that shape immobilized...
Tooth decay in the form of dental caries and cavities is estimated to be among the most common health conditions globally, with treatment of these oral diseases resulting in a massive, world-wide economic burden. The cause of this demineralization of teeth is rooted in the action of complex microbial biofilms...
Tropical fruit aromas are prominent in wines like Sauvignon Blanc, one of the most abundant white wines in the United States. With high consumer interest for these aromas, it has become increasingly important to understand the factors that influence the desired tropical fruit aromas in white wines. Understanding the causes...
The unique capability of carbon-based ion-selective electrode (ISE) to perform highly sensitive anodic stripping voltammetry, while maintaining all the properties of an ISE, is demonstrated in terms of sensitivity, detection limit, response time and selectivity. Square wave anodic stripping voltammetry involves deposition and dissolution steps of metal ions, which means...
The phases of transition alumina are scientifically interesting due to their high specific surface area, favorable acid/ base characteristics, and chemical and hydrothermal stability which make this metallic oxide a prime candidate for use as a support for metallic nanoparticles (NPs) in heterocatalysis. Interactions at alumina/Pt interfaces are important for...
Polyoxometalates (POMs) are anions consisting of three or more early transition metals ™ (Gr V and VI) oxoanions (in their highest oxidation state) linked together by a shared oxygen bond to form a 3D framework. Polyoxometalates (POMs) are a rapidly growing class of metal oxo clusters with a wide range...