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Micro-fabricated silicon cantilevers arrays offer a novel label-free approach where ligand-receptor binding interactions occurring on the sensor generate nanomechanical signals like bending or a change in mass that is optically detected in-situ. We report the detection of multiple unlabelled biomolecules simultaneously down to picomolar concentrations within minutes. Differential measurements including reference cantilevers on an array of eight sensors enable sequence-specifically detection of unlabelled DNA and are suitable to detect specific gene fragments within a complete genome (gene fishing). Expression of detection of inducible genes and the detection of total RNA fragments in an unspecific background will be shown.
Ligand-receptor binding interactions, such as antigen recognition will be presented. Antibody activated cantilevers with sFv (single chain fragments) which bind to the indicator proteins show a significantly improved sensitivity which is comparable with SPR (Surface Plasmon Resonance).
In addition this technology offers a broad variety of receptor molecules application such as e.g. membrane protein recognition, micro-organism detection, enantiomeric separation.
New coating procedures, enlargement of the active surface area by dendritic molecules as well as improvement of the receptor-cantilever chemical bond will be presented.
These new findings may lead to a novel individual diagnostic assay in a combined label-free GENOMICS and PROTEOMIC biomarker sensor (COMBIOSENS).
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