A method of assaying the interaction of a molecule and a lipid bilayer is described. The method employs a microfluidic device comprising a substrate having at least one concave microcavity with a metallic surface defining an aperture and a liquid disposed within the microcavity, a lipid bilayer suspended across the aperture, and a microfluidic channel containing a liquid disposed on top of the substrate in fluid communication with the lipid bilayer. The method comprises the steps of passing a liquid containing a test molecule across the microfluidic channel, and monitoring lipid bilayer molecule interactions by plasmonically enhanced Raman or fluorescence spectroscopy configured for plasmonic enhancement of a detection signal evolving from the test molecule or lipid bilayer. Also described in a microfluidic device configured to perform the method of the invention.