The most abundant biological thiols, homocysteine (Hcy), cysteine (Cys) and glutathione (GSH) have been the subject of intense research due to their association with a wide range of diseases. They play a key role in maintaining the redox status of biological systems. Selective detection methods for these thiols are challenging due to their similar structures and properties. Current commercially available detection methods use separations, fragile and expensive enzymatic or immunogenic materials and complex instrumentation. This has led to a global effort towards developing simple and inexpensive optical probes and indicators selective for specific biological thiols. Highly selective chemical probes and simple methods for detection and potential quantification of Hcy and GSH in their natural biological media have been developed. These indicators and methods are relatively simple and inexpensive for potential application at point of care. The selective detection of Hcy using novel asymmetric viologen chemical probes at room temperature is described as well as the use of commercially available materials under photochemical conditions. These probes respond linearly proportional to increasing Hcy concentrations, potentially enabling the monitoring of Hcy levels in human plasma. Additionally, new methods for the selective determination of GSH in human plasma, as well as its quantification in whole blood deposited on filter paper (dried blood spots), is also presented herein.

Supramolecular chemists can be thought of as architects, who combine individual non-covalently bonded molecular building blocks, designed to be held together by intermolecular forces to create functional architectures. Perhaps the most important assets of a supramolecular chemist, however, are imagination and creativity, which have given rise to a wide range of beautiful and functional systems. For years, analytical chemistry has taken advantage of supramolecular assemblies in the development of new analytical methods. The role of synthetic supramolecular chemistry has proven to be a key component in this multidisciplinary research. As such, the demand for synthetic receptors is rapidly increasing within the analytical sciences. The field “supramolecular analytical chemistry” involves analytical applications of synthetic organic and inorganic chemical structures that display molecular recognition properties and self-assembly but also signal these events. Chapter 1 presents an introduction to the background literature relevant to the central themes of the research presented in this thesis. The nonthermal production of visible light by a chemical reaction leads to the term “cool light”, and the process is called chemiluminescence. Although chemiluminescent reactions are not rare, the production of “cool light” holds such fascination for both chemists and nonchemists that demonstrations of chemiluminescent reactions are always well received. A glow assay technology for the detection of a chemical warfare simulant is presented in Chapter 2, which is based on modulating the peroxyoxalate chemiluminescence pathway by way of utilizing an oximate super nucleophile that gives an off-on glow response. As an alternative to highly analyte-specific synthetic receptors, trends in chemical sensing have shifted to the design of new materials and devices that rely on a series of chemo- or biosensors. The research relevant to Chapter 3 focuses on investigating the use of a single receptor, for sensing two different analytes; thiols and metal ions, utilizing a squaraine as the receptor in a sensor array format. The data is interpreted with principal component analysis. Finally Chapter 4 discusses an attempt to design and synthesize a chemosensor based on the luminophore-spacer-receptor format by incorporating the two concepts photoinduced electron transfer and peroxyoxalate chemiluminescence. / text