Amine functionalized SU-8 layer guiding Love mode surface acoustic wave

The chemical functionalization of SU-8 photoresist with amine-ended silanes is demonstrated. The resulting active layer, coated on a quartz substrate, is used for propagating guided surface acoustic waves: its acoustic properties are used for the development of a chemical sensor for in situ analysis of aqueous solutions. The analytical principle is demonstrated by measuring with time resolution the binding of organometallic complexes of molar weight in the 250 g/mol range. The acoustic signal is interpreted as a pure mass effect, with a non-selective detection limit of the sensor of 60 ng/cm2.