FTIR-ATR biosensor based on self-assembled phospholipids surface: Haemophilia factor VIII diagnosis

Abstract

We report a new generic device suitable for the investigation of biological interactions by means of Fourier Transform Infrared (FTIR) spectroscopy. The research is focused on multi reflected evanescent optical radiation through a chemically modified surface of the attenuated total reflection (ATR) element (silicon or germanium). Using a wet chemistry approach, the original method is based on grafting of a bifunctional binding molecule (N-hydroxysuccinimidyl ester forms) at the surface of the Si or the Ge crystals. The functionalized surface permits then the foundation of different types of self-assembled phospholipid membranes. The obtained sensors allow the detection, in infrared spectral domain, of any perceptible molecular interaction or structural changes. The key experimental result concerns the coagulation factor VIII _(FVIII). The principle of the diagnostic is related to the ability of F_FVIII molecules to bind specifically to phosphatidylserine (PS) membrane.