title: Multiplex protein assays based on real-time magnetic nanotag sensing.
abstract: Magnetic nanotags (MNTs) are a promising alternative to fluorescent labels in biomolecular detection assays, because minute quantities of MNTs can be detected with inexpensive giant magnetoresistive (GMR) sensors, such as spin valve (SV) sensors. However, translating this promise into easy to use and multilplexed protein assays, which are highly sought after in molecular diagnostics such as cancer diagnosis and treatment monitoring, has been challenging. Here, we demonstrate multiplex protein detection of potential cancer markers at subpicomolar concentration levels and with a dynamic range of more than four decades. With the addition of nanotag amplification, the analytic sensitivity extends into the low fM concentration range. The multianalyte ability, sensitivity, scalability, and ease of use of the MNT-based protein assay technology make it a strong contender for versatile and portable molecular diagnostics in both research and clinical settings.
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
authors.forename: Sebastian J
authors.initials: SJ
authors.lastname: Osterfeld
authors.forename: Heng
authors.initials: H
authors.lastname: Yu
authors.forename: Richard S
authors.initials: RS
authors.lastname: Gaster
authors.forename: Stefano
authors.initials: S
authors.lastname: Caramuta
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.forename: Shu-Jen
authors.initials: SJ
authors.lastname: Han
authors.forename: Drew A
authors.initials: DA
authors.lastname: Hall
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Wilson
authors.forename: Shouheng
authors.initials: S
authors.lastname: Sun
authors.forename: Robert L
authors.initials: RL
authors.lastname: White
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Davis
authors.forename: Nader
authors.initials: N
authors.lastname: Pourmand
authors.forename: Shan X
authors.initials: SX
authors.lastname: Wang
mesh_terms: D001681:Biological Assay / Q000295:instrumentation / Q000379:methods*; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D008280:Magnetics / Q000295:instrumentation / Q000379:methods; D025202:Molecular Diagnostic Techniques / Q000295:instrumentation / Q000379:methods*; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor