The 77th JSAP Autumn Meeting, 2016

Presentation information

Symposium (Oral)

Symposium » English session: Joint symposium on Nanobiotechnology and Biosensing

[13p-B1-1~13] English session: Joint symposium on Nanobiotechnology and Biosensing

Tue. Sep 13, 2016 1:15 PM - 6:00 PM B1 (Exhibition Hall)

Atsushi Miura(Hokkaido Univ.), Koichiro Miyamoto(Tohoku Univ.)

1:15 PM - 2:00 PM

[13p-B1-1] Magnetic nanoparticles for medical diagnostics

Adarsh Sandhu1 (1.UEC, Tokyo)

Keywords:biosensing, Hall effect, magnetism

The majority of patients are unaware that gadolinium-based paramagnetic nanoparticles play a critical part in high enhancing the contrast of magnetic resonance imaging (MRI). Such solutions are called ‘contrast agents’ and are injected into the blood stream of patients prior to MRI examination. The magnetic particles yield high contrast images of the brain and other organs due to the interaction of the large magnetic fields applied during MRI with the iron oxide particles circulating in the blood stream.

Such contrast agents are an example of the unique applications of magnetic particles for medical diagnosis of ailments such a cancer. Here, I will describe my group’s research on the use of magnetic nanoparticles as ‘magnetic labels’ for medical diagnostics. Specifically, I will describe the integration of Hall effect magnetic field sensors and magnetic nanoparticles for point of care biosensing protocols based on InSb/InAs and GaAs/AlGaAs Hall devices for sensitive and rapid detection of superparamagnetic beads [1,2,3].

Intriguingly, paramagnetic nanoparticles form robust ‘chains’ under external magnetic fields. We have exploited this phenomenon to develop ‘label-less homogenous’ medical diagnostic procedures—magneto-optical transmission sensing—where the optical transmission of a colloid containing rotating chains of magnetic of nanobeads enables the detection biomolecules with pM-level sensitivity with a dynamic range of more than four orders of magnitude [4].

I will conclude by describing biosensing based on magnetically induced self-assembly of superparamagnetic beads and nonmagnetic beads, and new ideas for ‘magnetic washing’ and biosensing with fluorescent magnetic nanobeads [5,6]