<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Biofunctionalization of GaN/AlGaN/GaN High Electron Mobility Transistors"^^ . "The primary aim of this thesis is the creation of new electrochemical biosensor systems \r\non solution-gated GaN/AlGaN/GaN high electron mobility transistors (HEMT) for the \r\ntransduction of biological functions into electrical readouts. For this purpose, the surface \r\nof transistors was functionalized with various biomimetic and bioorganic molecular \r\nsystems, such as helical peptides, lipid monalayers and membranes. The full \r\ncharacterization of thickness, roughness, and density of such biomimetic molecular \r\nassemblies enables to quantitatively translate the change in surface monopoles and \r\ndipoles into the carrier mobility.\r\nIn Chapter 4, monolayers of bio-inspired, non-biological helical peptides were deposited \r\non GaN semiconductor surfaces in order to modulate the electronic band structures of \r\nGaN by macromolecular dipole moments. By covalently coupling the peptides via N- or \r\nC-terminus to the GaN surfaces, the sign (direction) of exerted dipole moments could \r\nprecisely be controlled, realizing the modulation of the carrier mobility. Moreover, the \r\nchronoamperometry measurements have demonstrated the additional ferrocene terminal \r\ngroup enables the directed electron transfer through peptide chains via an inelastic \r\nhopping mechanism.\r\nIn Chapter 5.3, cell membrane models were deposited on the GaN surfaces pre-coated \r\nwith hydrophobic, organic silane monolayers. By incorporating lipids with nitrilotriacetic \r\nacid (NTA) head groups into lipid membranes, changes in the surface potentials induced \r\nby the binding of charged recombinant proteins to the surface lipid membranes could be \r\ndetected at a high sensitivity. The systematic variation of surface density of NTA lipids \r\nand the comparison with impedance spectroscopy data of bulk GaN electrodes, it has \r\nbeen demonstrated that the sensitivity of this system to changes in the surface charge \r\ndensity is as high as ΔQ < 0.1 μC/cm2.\r\nIn Chapter 5.2, to accommodate the incorporation of transmembrane proteins under nondenaturing conditions, a more realistic cell membrane model, bilayer lipid membranes, \r\nwas deposited on GaN by using regenerated cellulose films as the polymer support. The \r\ncurrent-voltage characteristics clearly indicated the high electric resistance of lipid \r\nmembranes, which seems promising for the detection of molecular recognition and \r\nselective material transport.\r\nLast but not least, such molecular constructs were transferred onto the surface of \r\nmolecularly thin, organic semiconductors that have shown a high charge mobility under \r\ndry conditions (Chapter 6). The preliminary attempts already demonstrated the formation \r\nof uniform lipid monolayers on organic semiconductor surfaces exposing hydrocarbon \r\nchains. Moreover, the reversible binding and unbinding of recombinant proteins has been \r\nconfirmed. Although further optimization of the device geometry and Ohmic contacts are \r\nnecessary, the data suggest a large potential of all organic electronic sensors operating \r\nunder water. \r\nThe obtained results highlighted the potential of the combination of biomimetic molecular \r\nconstructs and inorganic and organic semiconductor devices for the highly sensitive and \r\nquantitative determination of properties and functions under physiological conditions."^^ . "2019" . . . . . . . "Sven"^^ . "Mehlhose"^^ . "Sven Mehlhose"^^ . . . . . . "Biofunctionalization of GaN/AlGaN/GaN High Electron Mobility Transistors (PDF)"^^ . . . "Dissertation Sven Mehlhose 2019.pdf"^^ . . . "Biofunctionalization of GaN/AlGaN/GaN High Electron Mobility Transistors (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #26523 \n\nBiofunctionalization of GaN/AlGaN/GaN High Electron Mobility Transistors\n\n" . "text/html" . . . "530 Physik"@de . "530 Physics"@en . . . "540 Chemie"@de . "540 Chemistry and allied sciences"@en . .