title: Monitoring protein distributions based on patterns generated by protein adsorption behavior in a microfluidic channel.
abstract: We report a unique monitoring technique of protein distributions based on distinctive patterns generated by protein adsorption behavior on a solid surface in a microfluidic channel. Bare gold and COOH-modified self-assembled monolayer (SAM) sensing surfaces were pre-adsorbed with one of four different proteins: lysozyme, albumin, transferrin, or IgG. Each surface provides a thermodynamically governed platform for immobilizing proteins and generates analyte-specific response patterns. Each surface has its own thermodynamic energy governing pre-adsorbed protein behaviors, so that sample proteins react with the pre-adsorbed ones to different extents depending on their sizes, isoelectric points (pI), and characteristics of the sensing surfaces. Modified surfaces were mounted and monitored in real time using surface plasmon resonance (SPR). Buffer-prepared sample matrices (α1-antitrypsin, haptoglobin, C-reactive protein (CRP), and IgM) characterized protein response patterns. Each surface generated distinctive patterns based on individual SPR angle shifts. We classified each sample with 95% accuracy using linear discriminant analysis (LDA). Our method also discriminated between different concentrations of CRP in the cocktail sample, detecting concentrations as low as 1 nM with 91.7% accuracy. This technique may be integrated with a microfluidic lab-on-a-chip system and monitor the distribution of a specific group of proteins in human serum.
authors.affiliation: School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona, USA. shchoi2@asu.edu
authors.forename: Seokheun
authors.initials: S
authors.lastname: Choi
authors.forename: Shuai
authors.initials: S
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Junseok
authors.initials: J
authors.lastname: Chae
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000737:chemistry*; D016002:Discriminant Analysis; D006046:Gold / Q000737:chemistry; D006801:Humans; D046210:Microfluidic Analytical Techniques; D020349:Surface Plasmon Resonance; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D001798:Blood Proteins; D006046:Gold