TY - JOUR
T1 - Using Magnetic Field Gradients to Shorten the Antigen-Antibody Reaction Time for a Magnetic Immunoassay
AU - Tsukada, Keiji
AU - Tsunashima, Kenta
AU - Jinno, Katsuya
AU - Hiramatsu, Bunta
AU - Takeuchi, Shun
AU - Fujimoto, Kayo
AU - Sakai, Kenji
AU - Kiwa, Toshihiko
AU - Saari, Mohd Mawardi
N1 - Funding Information:
ACKNOWLEDGMENT This work was supported by the Grant-in-Aid for Scientific (S) through the Japan Society for the Promotion of Science under Grant JP15H05764. The authors would like to thank Prof. K. Enpuku, Kyushu University, and Dr. T. Mizoguchi and A. Kandori, Hitachi Ltd., and Dr. M. Hara, Tamagawa Seiki Co., Ltd., for helpful supports on the C-reactive protein measurement.
PY - 2019/7
Y1 - 2019/7
N2 - The measurement of biological targets using nanoparticle magnetic markers has been extensively studied for its applications in magnetic immunoassays (MIAs). Compared with the optical immunoassay method, the MIA methods have some attractive characteristics such as a wash-free process that does not need bound/free marker separation and the ability to detect biological targets in a nebulous liquid. In addition, the wash-free process is very fast. In this paper, we tried to reduce the reaction time for the antigen-antibody reaction in order to make the MIA method more attractive. The reduction in reaction time and the detection characteristic of biological targets were demonstrated using C-reactive proteins (CRPs) as biological targets for diagnosing inflammation. To shorten the reaction time, a magnetic-shaking method using the magnetic field gradient from a neodymium magnet was developed. When comparing the reaction times with and without magnetic shaking, it was found that the reaction time decreased with magnetic shaking for all CRP concentrations. Even after the magnetic-shaking treatment, the dependence of the CRP concentration on the magnetic signal was observed. The number of surface modifications per magnetic marker and the magnetic marker concentration also affected the reaction time. In order to obtain the desired measurement range based on the CRP response characteristic, it is necessary to optimize the number of magnetic markers and polymer beads used.
AB - The measurement of biological targets using nanoparticle magnetic markers has been extensively studied for its applications in magnetic immunoassays (MIAs). Compared with the optical immunoassay method, the MIA methods have some attractive characteristics such as a wash-free process that does not need bound/free marker separation and the ability to detect biological targets in a nebulous liquid. In addition, the wash-free process is very fast. In this paper, we tried to reduce the reaction time for the antigen-antibody reaction in order to make the MIA method more attractive. The reduction in reaction time and the detection characteristic of biological targets were demonstrated using C-reactive proteins (CRPs) as biological targets for diagnosing inflammation. To shorten the reaction time, a magnetic-shaking method using the magnetic field gradient from a neodymium magnet was developed. When comparing the reaction times with and without magnetic shaking, it was found that the reaction time decreased with magnetic shaking for all CRP concentrations. Even after the magnetic-shaking treatment, the dependence of the CRP concentration on the magnetic signal was observed. The number of surface modifications per magnetic marker and the magnetic marker concentration also affected the reaction time. In order to obtain the desired measurement range based on the CRP response characteristic, it is necessary to optimize the number of magnetic markers and polymer beads used.
KW - Antigen-antibody reaction
KW - C-reactive protein (CRP)
KW - magnetic field gradients
KW - magnetic immunoassay (MIA)
KW - magnetic nanoparticles (MNPs)
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U2 - 10.1109/TMAG.2019.2894904
DO - 10.1109/TMAG.2019.2894904
M3 - Article
AN - SCOPUS:85067829217
VL - 55
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
SN - 0018-9464
IS - 7
M1 - 8637765
ER -