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Title: Liver cancer immunoassay with magnetic nanoparticles and MgO-based magnetic tunnel junction sensors
Authors: Lei, Z. Q.
Li, L.
Li, G. J.
Leung, C. W.
Shi, J.
Wong, C. M.
Lo, K. C.
Chan, W. K.
Mak, C. S. K.
Chan, S. B.
Chan, N. M. M.
Leung, C. H.
Lai, P. T.
Pong, P. W. T.
Subjects: Biosensors
Magnesium compounds
Magnetic particles
Tunnelling magnetoresistance
Issue Date: 1-Apr-2012
Publisher: American Institute of Physics
Source: Journal of applied physics, 1 Apr. 2012, v. 111, no. 7, 07E505, p. 1-3.
Abstract: We have demonstrated the detection of alpha-fetoprotein (AFP) labeled with magnetic nanoparticles (MNPs) using MgO-based magnetic tunnel junction (MTJ) sensors. AFP is an important hepatic tumor biomarker and the detection of AFP has significant applications for clinical diagnostics and immunoassay for early-stage liver cancer indications. In this work, MgO-based MTJ sensors and 20-nm iron-oxide magnetic nanoparticles (MNPs) were used for detecting AFP antigens by a sandwich-assay configuration. The MTJ sensors with a sensing area of 4 × 2 μm² possess tunneling magnetoresistance (TMR) of 122% and sensitivity of 0.95%/Oe at room temperature. The target AFP antigens of three concentrations were successfully detected, and the experimental data indicate that the resistance variations of the MTJ sensor increased with the AFP concentration ratios proportionally. These results demonstrate that MgO-based MTJ sensors together with MNPs are a promising biosensing platform for liver cancer immunoassay.
Rights: © 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Z. Q. Lei et al., J. Appl. Phys. 111, 07E505 (2012) and may be found at
Type: Journal/Magazine Article
DOI: 10.1063/1.3676212
ISSN: 0021-8979 (print)
1089-7550 (online)
Appears in Collections:AP Journal/Magazine Articles

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