Fluorescence Activation and Enhancement with Photogenerated Radicals, Pre-fluorescent Probes and Silver Nanostructures

This thesis proposes a boron-dipyrromethene (BODIPY) fluorophore-based radical sensing system covalently linked to 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), a paramagnetic nitroxide, known to quench fluorescence non-radiatively through electron exchange. Introduction of a free radical creates a diamagnetic product, resulting in the restoration of fluorescence due to the inhibition of its quenching pathway. This has been successfully applied to the activation of a pre-fluorescent system with the addition of metal enhanced fluorescence via silver nanoparticles. Further research looks at extending the π conjugation of the BODIPY based pre-fluorescent probe to bathochromically shift its spectroscopic properties to enhance its potential in biological monitoring applications.