Gold nanoclusters and fluorescence-based sensing

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The main topic of this dissertation focuses on development of analytical methods, mainly modification and application of metal nanoclusters in fluorescence-based sensing. Based on bovine serum albumin passivated gold nanoclusters (AuNCs@BSA) we firstly developed a fluorescent biosensor platform, combining cholesterol oxidase with assistance of surfactant, for selective detection of water insoluble analyte, cholesterol in aqueous condition. Moreover, we designed a series of modification strategy to enhence thermal reversibility of AuNCs@BSA, aiming at reducing hysteresis remained during thermal cycles. Taking advantage of optimized thermal reversibility in terms of fully recoverable fluorescence intensity, analytical performance of modified AuNCs@BSA was investigated and an aqueous-phase temperature sensor was achieved. In addition to AuNCs, we developed novel glutathione stabilized copper NCs with green-emission in assistance of ascorbic acid reduction, which showed great resistance to nitro compounds. Further, analytical application of as-prepared Cu NCs to ratiometric sensing on explosive molecules, cooperating with AuNCs@BSA, was investigated. In the last, a novel and facile temperature mapping method using ionic liquid and organic fluorescent molecular rotor were described. Making use of viscosity-sensitive fluorescent dye, temperature was converted to ratio value of fluorescence intensity and recorded, enabling visualized thermal map.Includes bibliographical references