Hall Biosensor With Integrated Current Microstrips for Control of Magnetic Beads

Kumagai, Yoshimichi; Togawa, Kiyoshi; Sakamoto, Satoshi; Abe, Masanori; Handa, Hiroshi; Sandhu, Adarsh

doi:10.1109/tmag.2006.879613

Cited by 8 publications

(6 citation statements)

References 8 publications

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“…For the dynamic and static detection schemes reported in this paper, the magnetic field and spatial resolutions are presently limited by at least one order of magnitude due to the large parasitic inductive voltage of about 1 mV. This can be overcome by compensating the flux loops in the printed circuit board design or by using on-chip integrated current lines [38] to locally gen- erate magnetic fields that will polarize and magnetically guide the beads inside microfluidic channels in lab-on-chip devices.…”

Section: Discussionmentioning

confidence: 99%

Single Superparamagnetic Bead Detection and Direct Tracing of Bead Position Using Novel Nanocomposite Nano-Hall Sensors

Gabureac

Bernau

Boero

et al. 2013

IEEE Trans. Nanotechnology

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We show that nanocomposite materials consisting of superparamagnetic nanoparticles embedded in a matrix are very good candidates for a novel generation of Hall nanosensors with high spatial and magnetic resolution, capable of detecting superparamagnetic beads suspended at different heights on top of the sensor. Two detection schemes were used: 1) static-the bead was centered on top of the sensor and detected with a combination of ac and dc orthogonal magnetic fields, and 2) dynamic-using nanomanipulation in an electron microscope for moving the bead precisely at different heights above the sensor and using only one magnetic field (ac). The Hall sensors were directly written by focusedelectron-beam-induced deposition and the active area was refined by focused ion beam milling. A magnetic field resolution of about 300 μT(Hz) −1 /2 and a spatial resolution of 230 nm(Hz) −1 /2 were measured. Both resolutions could be improved by at least an order of magnitude with the suppression of the parasitic inductive signals.

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Section: Discussionmentioning

confidence: 99%

Single Superparamagnetic Bead Detection and Direct Tracing of Bead Position Using Novel Nanocomposite Nano-Hall Sensors

Gabureac

Bernau

Boero

et al. 2013

IEEE Trans. Nanotechnology

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“…We are also developing the technique of “magnetic washing” for magnetically removing nonspecifically-bonded nano-sized particles on the surfaces of biosensors. Our approach is based on a magnetic field gradient induced by a current passed through gold micro-lines integrated with the substrate [ 14 ] as shown schematically in Figure 21 . The magnitude of the magnetic field gradient is controlled by varying the dimensions of the gold pattern microlines as described in a report on Hall effect biosensors.…”

Section: Recent Work With Industrial Productsmentioning

confidence: 99%

“… The basic concept of “magnetic washing” via magnetic field gradient, induced by an applied current thorough a gold layer. Adapted from [ 14 ]. …”

Section: Recent Work With Industrial Productsmentioning

confidence: 99%

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Magnetic-Particle-Sensing Based Diagnostic Protocols and Applications

Takamura

Sharma

et al. 2015

Sensors

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Magnetic particle-labeled biomaterial detection has attracted much attention in recent years for a number of reasons; easy manipulation by external magnetic fields, easy functionalization of the surface, and large surface-to-volume ratio, to name but a few. In this review, we report on our recent investigations into the detection of nano-sized magnetic particles. First, the detection by Hall magnetic sensor with lock-in amplifier and alternative magnetic field is summarized. Then, our approach to detect sub-200 nm diameter target magnetic particles via relatively large micoro-sized “columnar particles” by optical microscopy is described. Subsequently, we summarize magnetic particle detection based on optical techniques; one method is based on the scattering of the magnetically-assembled nano-sized magnetic bead chain in rotating magnetic fields and the other one is based on the reflection of magnetic target particles and porous silicon. Finally, we report recent works with reference to more familiar industrial products (such as smartphone-based medical diagnosis systems and magnetic removal of unspecific-binded nano-sized particles, or “magnetic washing”).

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“…Based on such reports for GMR and spin valve sensors, we designed a Hall biosensor with Au microstrips to generate field gradients by passing direct currents (dc) through the microstrips [97,98] to move and collect SPBs onto the surfaces of micro-Hall biosensors. Our design (figure 22) enabled large displacements of magnetic beads with currents of only a few mA, thus limiting local heating that may adversely affect molecular recognition processes.…”

Section: Biosensing Using Hall Biosensorsmentioning

confidence: 99%

Synthesis and applications of magnetic nanoparticles for biorecognition and point of care medical diagnostics

2010

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Functionalized magnetic nanoparticles are important components in biorecognition and medical diagnostics. Here, we present a review of our contribution to this interdisciplinary research field. We start by describing a simple one-step process for the synthesis of highly uniform ferrite nanoparticles (d = 20-200 nm) and their functionalization with amino acids via carboxyl groups. For real-world applications, we used admicellar polymerization to produce 200 nm diameter 'FG beads', consisting of several 40 nm diameter ferrite nanoparticles encapsulated in a co-polymer of styrene and glycidyl methacrylate for high throughput molecular screening. The highly dispersive FG beads were functionalized with an ethylene glycol diglycidyl ether spacer and used for affinity purification of methotrexate-an anti-cancer agent. We synthesized sub-100 nm diameter magnetic nanocapsules by exploiting the self-assembly of viral capsid protein pentamers, where single 8, 20, and 27 nm nanoparticles were encapsulated with VP1 pentamers for applications including MRI contrast agents. The FG beads are now commercially available for use in fully automated bio-screening systems. We also incorporated europium complexes inside a polymer matrix to produce 140 nm diameter fluorescent-ferrite beads (FF beads), which emit at 618 nm. These FF beads were used for immunofluorescent staining for diagnosis of cancer metastases to lymph nodes during cancer resection surgery by labeling tumor cell epidermal growth factor receptor (EGFRs), and for the detection of brain natriuretic peptide (BNP)-a hormone secreted in excess amounts by the heart when stressed-to a level of 2.0 pg ml(-1). We also describe our work on Hall biosensors made using InSb and GaAs/InGaAs/AlGaAs 2DEG heterostructures integrated with gold current strips to reduce measurement times. Our approach for the detection of sub-200 nm magnetic bead is also described: we exploit the magnetically induced capture of micrometer sized 'probe beads' by nanometer sized 'target beads', enabling the detection of small concentrations of beads as small as 8 nm in 'pumpless' microcapillary systems. Finally, we describe a 'label-less homogeneous' procedure referred to as 'magneto-optical transmission (MT) sensing', where the optical transmission of a solution containing rotating linear chains of magnetic nanobeads was used to detect biomolecules with pM-level sensitivity with a dynamic range of more than four orders of magnitude. Our research on the synthesis and applications of nanoparticles is particularly suitable for point of care diagnostics.

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Hall Biosensor With Integrated Current Microstrips for Control of Magnetic Beads

Cited by 8 publications

References 8 publications

Single Superparamagnetic Bead Detection and Direct Tracing of Bead Position Using Novel Nanocomposite Nano-Hall Sensors

Single Superparamagnetic Bead Detection and Direct Tracing of Bead Position Using Novel Nanocomposite Nano-Hall Sensors

Magnetic-Particle-Sensing Based Diagnostic Protocols and Applications

Synthesis and applications of magnetic nanoparticles for biorecognition and point of care medical diagnostics

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