Pattern generation of a microfluidic-based biosensor to detect C-reactive protein using the competitive protein adsorption

We report a microfluidic-based protein sensing technique using pattern generation of a mixture of multiple proteins based on the competitive protein adsorption. We prepared four pre-adsorbed surfaces: lysozyme, albumin, transferrin, and IgG, on a gold surface, to obtain a selective and sensitive detection of a target protein, C-reactive protein (CRP) in a controlled cocktail. The microfluidic device was coupled with a Surface Plasmon Resonance (SPR), to monitor molecular reaction in real time. A matrix of proteins mixtures (α1-antitrypsin, haptoglobin, CRP, and IgM) was generated to characterize the biosensor. Each surface interacted differently with a given sample and as a set generated a specific pattern based on individual SPR angle shifts. Using Linear Discriminant Analysis (LDA), we classified each protein and identified CRP selectively with an identification accuracy of 95 %.