Microcantilever-based biosensors

The use of surface stress-based sensors as bio-chemical sensors was investigated. In principle, adsorption of biochemical species on a functionalised surface of a microfabricated cantilever will cause surface stress and consequently the cantilever bends. Two applications are presented: first lipoproteins and their oxidised form which are responsible for cholesterol accumulation in arteries were differentiated by measuring the surface stress involved in their adsorption on a sugar (heparin); secondly, the surface stress resulting from surface induced conformational changes in protein was monitored. That provided experimental evidence of long time-scale surface processes.