title: An enzymatic immunoassay microfluidics integrated with membrane valves for microsphere retention and reagent mixing.
abstract: The present study presents a new microfluidic device integrated with pneumatic microvalves and a membrane mixer for enzyme-based immunoassay of acute myocardial infarction (AMI) biomarkers, namely, myoglobin, and heart-type fatty acid binding protein (H-FABP). Superparamagnetic microspheres with carboxyl groups on their surfaces were used as antibody solid carriers. A membrane mixer consisting of four ψ-type membrane valves was assembled under the reaction chamber for on-chip performing microsphere trapping and reagent mixing. The entire immunoassay process, including microsphere capture, reagent input, mixing, and subsequent reaction, was accomplished on the device either automatically or manually. The post-reaction substrate resultant was analyzed using a microplate reader. The results show that the average absorbance value is correlated with the concentration of cardiac markers, in agreement with the results obtained using a conventional microsphere-based immunoassay; this indicated that the proposed on-chip immunoassay protocol could be used to detect both myoglobin and H-FABP. The minimum detectable concentration is 5 ng/mL for myoglobin and 1 ng/mL for H-FABP.
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Ren
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Jian-Chun
authors.initials: JC
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China; College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Wenming
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Tu
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Yaolei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China; College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China. Electronic address: jywang@nwsuaf.edu.cn.
authors.forename: Jinyi
authors.initials: J
authors.lastname: Wang
mesh_terms: D015415:Biomarkers / Q000032:analysis; D004867:Equipment Design; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques / Q000295:instrumentation*; D007202:Indicators and Reagents; D008280:Magnetics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008863:Microspheres; D009203:Myocardial Infarction / Q000175:diagnosis / Q000378:metabolism; D009211:Myoglobin / Q000032:analysis
chemical_list: D015415:Biomarkers; C493408:FABP3 protein, human; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins; D007202:Indicators and Reagents; D009211:Myoglobin