Detection of Amyloid Beta Fibril Growth by Liposome-Immobilized Micro-Cantilever With NiCr Thin-Film Strain Gauge

A micro-cantilever with thermally stable strain gauge of a NiCr thin film and a self-assembled monolayer was fabricated by surface micromachining. Liposomes, as biosensing molecules, were immobilized on its surface. To prevent evaporation of the water solvent, a reservoir made of polydimethylsiloxane around the micro-cantilever was fabricated and covered with a glass plate. The resistance of the strain gauge increases with time in the amyloid beta (Aβ) solution, because the cantilever is bent downward caused by interaction between Aβ and liposomes immobilized on the micro-cantilever surface. Moreover, resistance change depends on the interaction ability of Aβ proteins with liposomes. It is therefore indicated that the fabricated static mode micro-cantilever sensor with immobilized liposomes can be used to detect Aβ proteins.