Hyper-high-sensitivity wash-free magnetoreduction assay on biomolecules using high- Tc superconducting quantum interference devices

Jen-Je Chieh, Shieh-Yueh Yang, Z. F. Jian, W. C. Wang, Herng-Er Horng, Hong-Chang Yang, Chin Yih Hong

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43 Citations (Scopus)


In this work, we develop a platform for assaying biomolecules involving the measurement of alternating current (ac) magnetoreduction of magnetic reagent mixed with a detected sample. The magnetic reagent contains magnetic nanoparticles coated with a given kind of antibody, which associates with conjugated biomolecules. Then, the biomolecules can be quantitatively detected by measuring the ac magnetoreduction of magnetic reagent. To achieve hyper-high-sensitivity assay, a system utilizing a high-transition-temperature rf superconducting quantum interference device (SQUID) as a sensor to probe the magnetoreduction of reagent due to the association between biomolecules and magnetic nanoparticles. Examples to assay multiactive epitope, single-active epitope, and small molecules are given to demonstrate the validity of the assay platform, as well as the hyper-high sensitivity.

Original languageEnglish
Article number014703
JournalJournal of Applied Physics
Issue number1
Publication statusPublished - 2008 Jan 22


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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