Giorgi Shtenberg
1Agricultural Research Organization, Volcani Center, Israel
Title: DNA directed immobilization as a tool for design of porous Si based biosensors
Biography
Biography: Giorgi Shtenberg
Abstract
The objective of this research is to design and construct porous Silicon (PSi) based biosensing platforms for monitoring proteolytic activity of complex proteases. Proteases regulate virtually every biological process, either during growth or maturation through the modification of protein activity or by controlling turnover. They have the unique ability to irreversibly hydrolyze peptide bonds, which results not only in protein degradation, but also in the introduction of new levels of information content into the signaling pathways. Despite their recognition as drug targets of great potential, the profile of their substrates or degradation products remains to be fully elucidated. To achieve this goal, we have designed and fabricated a simple optical biosensing platform based on PSi nanostructures that allows for real-time monitoring of protease activity and downstream mass spectrometry analysis of the substrate degradation products. An oxidized PSi optical nanostructure, a Fabry-Pérot thin film, is synthesized and is used as the optical transducer element. Immobilization of the protease onto the nanostructure is performed through DNA-directed immobilization. Our studies demonstrate high enzymatic activity of the immobilized proteases, while maintaining their specificity. The catalytic activity of the proteases immobilized within the porous nanostructure is monitored in real time by reflective interferometric Fourier transform spectroscopy, allowing us to both concentrate and quantify the reaction products. We show that we can easily regenerate the surface for additional biosensing analysis by mild dehybridization conditions. The biosensor configuration is compatible with common proteomic methods and allows for downstream mass spectrometry analysis of the reaction products.