caa a22 4500 605479658 CHVBK 20210128100411.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s10544-015-0022-2 doi (NATIONALLICENCE)springer-10.1007/s10544-015-0022-2 PicoMolar level detection of protein biomarkers based on electronic sizing of bead aggregates: theoretical and experimental considerations [Elektronische Daten] [Z. Lin, X. Cao, P. Xie, M. Liu, Mehdi Javanmard] We demonstrate a novel method for electronically detecting and quantifying protein biomarkers using microfluidic impedance cytometry. Our biosensor, which consists of gold electrodes micro-fabricated in a microchannel, detects the differences between bead aggregates of varying sizes in a micro-pore sandwiched between two micro channels. We perform a sandwich immunoassay, where the complementary antibody pairs are immobilized on two different bead types, and the presence of antigen results in bead aggregation, the amount of which depends on antigen quantity. When single beads or bead aggregates pass through the impedance sensor, differences in impedance change are detected. In this manuscript, we perform a comprehensive theoretical study on the limits imposed on sensitivity of this technique due to electronic noise and also mass transfer and reaction limits. We also experimentally characterize the performance of this technique by validating the technique on an IgG detection assay. A detection limit at the picoMolar level is demonstrated, thus comparable in sensitivity to a sandwich ELISA. Springer Science+Business Media New York, 2015 Protein biomarker detection nationallicence Microfluidics nationallicence Impedance Cytometry nationallicence Lin Z. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut Cao X. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut Xie P. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut Liu M. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut Javanmard Mehdi Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/6(2015-12-01), 1-7 1387-2176 17:6<1 2015 17 10544 https://doi.org/10.1007/s10544-015-0022-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-015-0022-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lin Z. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut NATIONALLICENCE 700 1- Cao X. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut NATIONALLICENCE 700 1- Xie P. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut NATIONALLICENCE 700 1- Liu M. Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut NATIONALLICENCE 700 1- Javanmard Mehdi Rutgers, The State University Of New Jersey, 08854, Piscataway, NJ, USA aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/6(2015-12-01), 1-7 1387-2176 17:6<1 2015 17 10544