Highly-sensitive magnetic sensor for detecting magnetic nanoparticles based on magnetic tunnel junctions at a low static field

Z. Jin, Thomas Myeongseok Koo, Myeong Soo Kim, M. Al-Mahdawi, M. Oogane, Y. Ando, Young Keun Kim

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

Magnetic sensors to detect magnetic nanoparticles (MNPs) towards biomedical applications require very high sensitivity at low magnetic fields. Here we report a magnetic sensor consisting of a magnetic tunnel junction (MTJ) with a synthetic antiferromagnetic free layer. This sensor exhibits a low magnetic anisotropy and sensitivities of over 18%/Oe at low fields in the range of 0 to 3 Oe. We employ superparamagnetic MNPs with a large diameter of 200 nm. The sensor's transfer curves show the magnetoresistance (MR) variations as a function of MNP concentration. We demonstrate the detection capability of MNP amounts of below 500 ng and low MNP concentrations of 0.01, 0.1, and 1 mg/ml in solvents. This result suggests that the combination of high-sensitivity TMR sensors and large MNPs has a substantial potential for biomarker detection applications.

Original languageEnglish
Article number015046
JournalAIP Advances
Volume11
Issue number1
DOIs
Publication statusPublished - 2021 Jan 1

Bibliographical note

Funding Information:
This research was supported by the S-Innovation program, the Japan Science and Technology Agency (JST, 201106007), the Center for Innovative Integrated Electronic System (CIES), the Center for Spintronics Research Network (CSRN), and the Organization for Advanced Studies, Center for Science and Innovation in Spintronics, the National Research Foundation of Korea (2019R1A2C3006587) and the Korea Evaluation Institute of Industrial Technology (10080408).

Publisher Copyright:
© 2021 Author(s).

ASJC Scopus subject areas

  • General Physics and Astronomy

Fingerprint

Dive into the research topics of 'Highly-sensitive magnetic sensor for detecting magnetic nanoparticles based on magnetic tunnel junctions at a low static field'. Together they form a unique fingerprint.

Cite this