title: Integrated Microfluidic Aptasensor for Mass Spectrometric Detection of Vasopressin in Human Plasma Ultrafiltrate.
abstract: We present a microfluidic aptamer-based biosensor for detection of low-molecular-weight biomarkers in patient samples. Using a microfluidic device that integrates aptamer-based specific analyte extraction, isocratic elution, and detection by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we demonstrate rapid, sensitive and label-free detection of arginine vasopressin (AVP) in human plasma ultrafiltrate. AVP molecules in complex matrices are specifically captured by an aptamer that is immobilized on microbeads via affinity binding in a microchamber. After the removal of unbound, contaminating molecules through washing, aptamer-AVP complexes are thermally disrupted via on-chip temperature control. Released AVP molecules are eluted with purified water and transferred to a separate microchamber, and deposited onto a single spot on a MALDI plate via repeated, piezoelectrically actuated ejection, which enriches AVP molecules over the spot area. This integrated on-chip sample processing enables the quantitative detection of low-abundance AVP by MALDI-TOF mass spectrometry in a rapid and label-free manner. Our experimental results show the detection of AVP in human plasma ultrafiltrate as low as physiologically relevant picomolar concentrations via aptamer-based selective preconcentration, demonstrating the potential of our approach as a rapid (~ 1hr), sensitive clinical AVP assay.
authors.affiliation: Department of Mechanical Engineering, Columbia University, New York, NY 10027, United States.
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Mechanical Engineering, Columbia University, New York, NY 10027, United States.
authors.forename: J
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: R
authors.initials: R
authors.lastname: Pei
authors.affiliation: Department of Medicine, Columbia University, New York, NY 10032, United States.
authors.forename: J A
authors.initials: JA
authors.lastname: Oliver
authors.affiliation: Department of Medicine, Columbia University, New York, NY 10032, United States.
authors.forename: D W
authors.initials: DW
authors.lastname: Landry
authors.affiliation: Department of Medicine, Columbia University, New York, NY 10032, United States.
authors.forename: M N
authors.initials: MN
authors.lastname: Stojanovic
authors.affiliation: Department of Mechanical Engineering, Columbia University, New York, NY 10027, United States.
authors.forename: Q
authors.initials: Q
authors.lastname: Lin