Integrated Microstructures to Improve Surface-Sample Interaction in Planar Biosensors

The integration of 3D microfluidic structures to enhance surface-sample interaction with microfluidic enclosed biosensors is reported. The method was tested in a device with a microfluidic network made from polydimethylsiloxane (PDMS), fabricated using a double layer mold technique. As an intermediate step before the tests, a self-assembled monolayer (SAM), which acted as a ligand for 252-nm amine-coated fluorescent polystyrene particles, was formed on top of a gold layer. The results showed that the microstructures produced an increase of coverage of the sensing areas up to 67% which, combined with the property of the SAM of binding with different biological molecules, provide a potential method to enhance the sensitivity of a wide range of multipurpose microfluidic biosensors.