Fast and Sensitive Measurement of Specific Antigen-Antibody Binding Reactions With Magnetic Nanoparticles and HTS SQUID

Author

Öisjöen, Fredrik ; Schneiderman, Justin Fleer ; Zaborowska, Magdalena ; Shunmugavel, Karthikeyan ; Magnelind, Per ; Kalaboukhov, Alexey ; Petersson, Karolina ; Astalan, Andrea Prieto ; Johansson, Christer ; Winkler, Dag

Author_Institution

Chalmers Univ. of Technol., Goteborg, Sweden

Volume

19

Issue

3

fYear

2009

fDate

6/1/2009 12:00:00 AM

Firstpage

848

Lastpage

852

Abstract

We have developed an HTS SQUID system for both time and frequency domain measurements of magnetic signals from the Brownian relaxation of liquid-suspended magnetic nanoparticles (MNPs) coated with antibodies. A planar YBa₂Cu₃O_7-x dc SQUID gradiometer with a baseline of 3 mm allows stable operation of the measurement system in an unshielded environment. Agglomeration of MNPs induced by prostate specific antigen-antibody binding complexes is characterized with our system and benchmarked with frequency domain measurements performed by Imego AB using an induction coil magnetometer. We estimate an upper bound for our immunoassay analyte sensitivity of 1.8 ng/radicHz.

Keywords

Brownian motion; SQUID magnetometers; barium compounds; biomagnetism; biomedical equipment; high-temperature superconductors; magnetic particles; nanobiotechnology; nanoparticles; suspensions; yttrium compounds; Brownian relaxation; HTS SQUID system; YBa₂Cu₃O_7-x; agglomeration; biomagnetics; frequency domain measurement; immunoassay analyte sensitivity; induction coil magnetometer; liquid-suspended magnetic nanoparticles; magnetic signals; planar dc SQUID gradiometer; prostate specific antigen-antibody binding complexes; size 3 mm; specific antigen-antibody binding reactions; time domain measurement; Benchmark; SQUIDs; biomagnetics; immunoassay; magnetic nanoparticles;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2009.2019246

Filename

5075613