TY - JOUR
T1 - Wash-free detection of biological target using cluster formation of magnetic markers
AU - Akiyoshi, Kazuki
AU - Yoshida, Takashi
AU - Sasayama, Teruyoshi
AU - Elrefai, Ahmed L.
AU - Hara, Misato
AU - Enpuku, Keiji
N1 - Funding Information:
This work was partly supported by the Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research (S) JP15H05764 and Grant-in-Aid for JSPS Fellows JP18F18349 .
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/4/15
Y1 - 2020/4/15
N2 - We demonstrate the wash-free detection of biological targets based on the Brownian relaxation of magnetic markers. The Brownian relaxation time of bound markers was prolonged by using a cluster (or agglomerate) of bound markers that was formed via the binding reaction between markers and targets. Thus, bound and free markers were differentiated magnetically by using the difference in their relaxation times. Two types of magnetic properties, i.e., third-harmonic signal and magnetic relaxation, were used for measurement. The concentration of target was detected from the decrease in the third-harmonic signal and the increase in the magnetic-relaxation signal. We demonstrated the detection of C-reactive proteins using these two properties. In both cases, a good correlation was obtained between the measured signal and the concentration of target. It was also shown that the two methods had different concentration dependences, which will be caused mainly by the distribution of cluster size of the bound markers.
AB - We demonstrate the wash-free detection of biological targets based on the Brownian relaxation of magnetic markers. The Brownian relaxation time of bound markers was prolonged by using a cluster (or agglomerate) of bound markers that was formed via the binding reaction between markers and targets. Thus, bound and free markers were differentiated magnetically by using the difference in their relaxation times. Two types of magnetic properties, i.e., third-harmonic signal and magnetic relaxation, were used for measurement. The concentration of target was detected from the decrease in the third-harmonic signal and the increase in the magnetic-relaxation signal. We demonstrated the detection of C-reactive proteins using these two properties. In both cases, a good correlation was obtained between the measured signal and the concentration of target. It was also shown that the two methods had different concentration dependences, which will be caused mainly by the distribution of cluster size of the bound markers.
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U2 - 10.1016/j.jmmm.2019.166356
DO - 10.1016/j.jmmm.2019.166356
M3 - Article
AN - SCOPUS:85077217283
SN - 0304-8853
VL - 500
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
M1 - 166356
ER -