Dissertation/Thesis Abstract

Water quality control using diversity oriented fluorescence library approach
by Wang, Xu, Ph.D., National University of Singapore (Singapore), 2015, 249; 10006110
Abstract (Summary)

Environment and nature are always amongst the top list of people’s concerns whereas environmental pollutants are more and more attracting intensive research throughout the world. Small molecule fluorescent sensors have stood out due to their high sensitivity and selectivity, cheap and easy measurement instruments, and facilely tunable emission range and structures. However, a large amount of both environmental and biological species lack their specific sensors and the designing is hampered by their eccentric properties. Diversity oriented fluorescence library approach (DOFLA) has come to tackle this issue from a different angle and this thesis summarizes the evolution of our in vitro screening approaches.

First of all, we designed an unbiased high-throughput screening method to conduct integrated screening of thousands of fluorescent dyes towards more than fifty biological analytes. This approach has allowed us a comprehensive understanding of dye properties and dye responses to the analytes. Caffeine orange (CO) was selected as a representative sensor developed through this method. After then, to quickly adapt the loads of fluorescent dyes to other species without the need of conducting the whole unbiased screening process again, we developed the screening format to an image-based hyper throughput screening approach. The setup of the whole screening system is simple and adaptable to any other dye and through this system, we have developed sensors for a variety of species, including food safety and social security species. One of the most outstanding sensor is for milk fat, which is no doubt its first fluorescent sensor.

The success of these stories has inspired to incorporate the image-based system with spectrometer system, and through designing of molecules, we have constructed a Singapore Tongue (SGT) sensor array targeting heavy metal ions in water systems. Not only are the SGT able to visualize and qualify multiple heavy metal ions, it is also capable of semi-quantifying these species. Most importantly, we have come up with a “safe zone” prototype that is able to exclusively and comprehensively detect any harmful heavy metal ion species from the drinking water samples. This could serve as a tool to replace the current complicated instrumental analysis. As a conclusion, the progress of fluorescent sensor development from DOFLA could trigger the enhancement of environmental monitoring.

Indexing (document details)
School: National University of Singapore (Singapore)
Department: Chemistry
School Location: Republic of Singapore
Source: DAI-B 77/06(E), Dissertation Abstracts International
Subjects: Organic chemistry
Publication Number: 10006110
ISBN: 978-1-339-43972-3
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