Prof. Dr. Lital Alfonta Department of Life Sciences, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev
* Genetically Engineering of Enzymes and Electrode Modifications for Biosensing Applications
Biosensing efficiency, selectivity and sensitivity relies first and foremost on a successful interfacing between enzymes and sensing surfaces. An Interface that allows from one hand a specific analyte recognition and on the other hand an efficient signal transduction. Some of the challenges in biosensing stem from wrong orientation of the enzyme towards the sensing interface and from the need to use mediated electron transfer with a diffusional redox mediator due to a difficulty in relaying a signal from a redox center that is deeply buried inside the protein matrix. Using genetic code expansion tools, and genetic engineering approaches we were able to modify redox enzymes and surfaces for biosensing and biofuel cell applications so they could have superior properties over native enzymes. In my talk, I will demonstrate how does site specific wiring of redox enzymes which is genetically encoded, can improve electron transfer due to controlled and short electron transfer distances and due to proper enzyme orientation. I will also demonstrate how a rational genetic engineering of an enzyme gives it superior properties for biosensing purposes compared to those of the native enzyme.
*ATP Synthesis and Biosensing Coupled to the Electroenzymatic Activity of a Hydrogenase on an Electrode/Biomimetic Membrane Interface
Cells generate energy by coupling a proton gradient across a phospholipid bilayer membrane with the activity of a cross-membrane ATP synthase enzyme. In an effort to mimic this process in an artificial environment, we show that ATP can be efficiently produced starting from molecular hydrogen as a fuel.
The proton concentration in an electrode/phospholipid bilayer interface can be controlled and monitorised electrochemically by immobilizing the membrane-bound [NiFeSe]-hydrogenase from Desulfovibrio vulgaris Hildenborough. The electro-enzymatic oxidation of H2 generated a proton gradient across the supported biomimetic membrane that can be coupled to the in vitro synthesis of ATP by reconstituting ATP-synthase from E. coli on the biomimetic system.Such system is also suitable for developing an electrochemical biosensor of ATP.
Structural health monitoring of aerospace, civil and mechanical structures and components is becoming increasingly relevant to minimize maintenance costs and provide additional layers of safety for the users. The session will focus on the progress of existing or novel sensing concepts including synergies among sensing approaches. All sensing mechanisms including piezoelectrics, piezoresistive, electrostrictives, magnetostrictives, shape memory alloys or polymers and optical are included in this session. Experimental studies are preferred but computational approaches that include applications and experimental results are also welcome. Presentations on data fusion, networking and computing of large amounts of data that are geared towards structural health monitoring applications are also encouraged in this session.