Detection of interaction between biological proteins and immobilized liposomes by a 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 (SAM) was fabricated by surface micromachining and liposomes, as biosensing molecules, were immobilized on its surface. The resistance of the strain gauge increases with time in a biological protein (carbonic anhydrase from bovine: CAB) solution because the cantilever is bent downward by surface adsorption of CAB molecules. On the other hand, the resistance changes differently with the growth of another type protein, amyloid beta (Aβ) fibrils. It is therefore demonstrated that the fabricated static mode micro-cantilever sensor can detect the interaction between the liposomes and the biological proteins.