A polydopamine patterned perfluoropolymer-based substrate for protein microarray applications

In this work, we developed a new composite substrate for protein microarrays, which was based on a per-fluorinated surface presenting the polydopamine (PDA) microspots array. Conventional protein microarray substrates often suffer from the high background noise and inconsistent signal quantification due to the nonspecific protein binding and non-uniform microspots morphology. The composite substrate in this work addressed these issues by taking advantages of the properties of the perfluorinated surface and PDA. The hydrophobic and oleophobic perfluorinated surface possessed good protein antifouling property with minimal nonspecific protein adsorption, while the PDA microspots provided the immobilization sites for the antibodies to anchor onto the surface to build the protein microarray. We fabricated the composite substrate by photolithography and optimized the protein microarray performance by tuning the surface roughness of the PDA microspots. To illustrate the applications of the composite substrate in protein microarray technology, we performed the immunoassay-based detection of cytokines.