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- All Subjects: Synthetic Biology
- All Subjects: engineering
molybdenum disulfide (MoS2), tungsten disulfide (WS2), molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2) are attractive for use in biotechnology, optical and electronics devices due to their promising and tunable electrical, optical and chemical properties. To fulfill the variety of requirements for different applications, chemical treatment methods are developed to tune their properties. In this dissertation, plasma treatment, chemical doping and functionalization methods have been applied to tune the properties of TMDCs. First, plasma treatment of TMDCs results in doping and generation of defects, as well as the synthesis of transition metal oxides (TMOs) with rolled layers that have increased surface-to-volume ratio and are promising for electrochemical applications. Second, chemical functionalization is another powerful approach for tuning the properties of TMDCs for use in many applications. To covalently functionalize the basal planes of TMDCs, previous reports begin with harsh treatments like lithium intercalation that disrupt the structure and lead to a phase transformation from semiconducting to metallic. Instead, this work demonstrates the direct covalent functionalization of semiconducting MoS2 using aryl diazonium salts without lithium treatments. It preserves the structure and semiconducting nature of MoS2, results in covalent C-S bonds on basal planes and enables different functional groups to be tethered to the MoS2 surface via the diazonium salts. The attachment of fluorescent proteins has been used as a demonstration and it suggests future applications in biology and biosensing. The effects of the covalent functionalization on the electronic transport properties of MoS2 were then studied using field effect transistor (FET) devices.
Industries and research utilizing genetically-engineered organisms are often subject to strict containment requirements such as physical isolation or specialized equipment to prevent an unintended escape. A relatively new field of research looks for ways to engineer intrinsic containment techniques- genetic safeguards that prevent an organism from surviving outside of specific conditions. As interest in this field has grown over the last few decades, researchers in molecular and synthetic biology have discovered many novel ways to accomplish this containment, but the current literature faces some ambiguity and overlap in the ways they describe various biocontainment methods. Additionally, the way publications report the robustness of the techniques they test is inconsistent, making it uncertain how regulators could assess the safety and efficacy of these methods if they are eventually to be used in practical, consumer applications. This project organizes and clarifies the descriptions of these techniques within an interactive flowchart, linking to definitions and references to publications on each within an Excel table. For each reference, variables such as the containment approach, testing methods, and results reported are compiled, to illustrate the varying degrees to which these techniques are tested.
Industries and research utilizing genetically-engineered organisms are often subject to strict containment requirements such as physical isolation or specialized equipment to prevent an unintended escape. A relatively new field of research looks for ways to engineer intrinsic containment techniques- genetic safeguards that prevent an organism from surviving outside of specific conditions. As interest in this field has grown over the last few decades, researchers in molecular and synthetic biology have discovered many novel ways to accomplish this containment, but the current literature faces some ambiguity and overlap in the ways they describe various biocontainment methods. Additionally, the way publications report the robustness of the techniques they test is inconsistent, making it uncertain how regulators could assess the safety and efficacy of these methods if they are eventually to be used in practical, consumer applications. This project organizes and clarifies the descriptions of these techniques within an interactive flowchart, linking to definitions and references to publications on each within an Excel table. For each reference, variables such as the containment approach, testing methods, and results reported are compiled, to illustrate the varying degrees to which these techniques are tested.