Invisible fluorinated materials for optical sensing

Fluorinated materials can be produced in order to combine an amorphous, homogenous structure and a refractive index very close to that of water. When in contact with aqueous solutions, such materials become barely visible. In these conditions, the adhesion of small amounts of molecules on their surface induces an optical signal that can be easily detected. This principle was exploited to realize novel label-free optical biosensors using either a dispersion of nanoparticles or a prism of fluorinated polymers as sensing substrates. The detection of specific molecular compounds in solution was achieved by suitable functionalization of the surface of the fluorinated materials.