Macroporous Polymer Cantilever Resonators for Chemical Sensing Applications

A novel, cost-effective strategy for sensing performance enhancement of cantilever-shaped, mass-sensitive sensors is presented. The developed strategy relies on the introduction of macroporosity in the recognition unit. The developed sensors are successfully applied in air humidity monitoring as well as in chemical sensing. As mass-sensitive transducers, polymer microelectromechanical systems (MEMS) in the form of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] cantilever resonators are specifically developed. These resonators are modified with a hierarchically structured macroporous poly(2,3'-bithiophene) film, acting as a sensing layer. The design of the recognition layer takes advantage of the synergistic combination of inverse opal structuring, surface imprinting, and semi-covalent imprinting of proteins. The resulting cantilever resonators are first successfully tested for air humidity monitoring in the whole relative humidity range (ca.10 - 90%). When the recognition layer is composed of human serum albumin-imprinted polymer (HSA-MIP) with a hierarchical structure, it can also be used as a selective chemosensor in a concentration range from 10 pM to 20 mu M. The obtained results demonstrate that the macroporosity of the receptor film significantly enhances the sensor performance.