THE USE OF PARAMAGNETIC PARTICLES FOR RAPID

DIAGNOSTICS

Richard Luxton

B.E.N

20th April 2010

•Paramagnetic particles•Application in diagnostics

Properties

• Size - nm – microns• Distribution of size

and shape• Fabrication type• Paramagnetic

material– Magnetite– Ni30Fe70

– NdFeBLa

Manufacture

• Mechanical– Magnetite

• Chemical– Iron Oxides, nickel, cobalt,– Gadolinium

• Biological 20 nm 2 nm

Fe2O3

www.cffs.uky.edu/Energy/Pubs/PhysRevB v70n17p174428y2004.pdf

Magnetospirillum gryphyswaldense

Typically 30 - 120 nm Isolated domains areSuper-paramagnetic below 30 nm

BiologicalNano-particles

Bacteria – iron oxides

Magnetic proteins

Paramagnetic material

Domains within paramagnetic

material are randomly aligned

Iron oxide - magnetite

Paramagnetic material

Apply a magnetic field

Paramagnetic material

Domains align with an applied magnetic

field

Paramagnetic material

Domains lose orientation over time -

Remanence

Remove magnetic field

Paramagnetic Material,

Polymer Layer

Capture-molecules covalently bonded to the polymer layer.

Target Cells or Molecules

Paramagnetic Material,

Polymer Layer

Capture-molecules covalently bonded to the polymer layer.

Target Cells or Molecules

Paramagnetic Material,

Polymer Core

Target Cells or Molecules

EstaporeDynabeadNano particles 10 -15 nm

Magneto-immunoassay

• Antibody coated surface

Y Y Y Y Y Y

MIA

• Antibody coated surface

• Reaction vessel

Y Y Y Y Y Y

MIA

• Antibody coated surface

• Reaction vessel

• Antibody coated PMP’s

Y Y Y Y Y Y

YY Y

Y

YY Y

Y

YY Y

Y

YY Y

Y

MIA

• Antibody coated surface

• Reaction vessel

• Antibody coated PMP’s

• Cross-linking antigen

Y Y Y Y Y Y

YY Y

Y

YY Y

Y

YY Y

Y YY Y

Y

MIA

• Antibody coated surface

• Reaction vessel

• Antibody coated PMP’s

• Cross-linking antigen

• Resonant coil

Y Y Y Y Y Y

YY Y

Y

YY Y

Y

YY Y

Y YY Y

Y

MIA

• Antibody coated surface

• Reaction vessel

• Antibody coated PMP’s

• Cross-linking antigen

• Resonant coil

Y Y Y Y Y Y

YY Y

Y

YY Y

Y

YY Y

Y YY Y

Y

MIA

• Antibody coated surface

• Reaction vessel

• Antibody coated PMP’s

• Cross-linking antigen

• Resonant coil

• Magnetic field

Y Y Y Y Y Y

YY Y

Y

YY Y

Y

YY Y

Y YY Y

Y

MIA

Resonant Coil Magnetometer

Phase Detector

Voltage Controlled Oscillator

Loop Filter

R

C

L

Frequency Meter

DC error signal

Detection of PMPs

Applications

• CKMB, Troponin I, CRP, Myoglobin• Transferrin, PSA, IL6• Bacteria• Intracellular

protein• DNA

0

200

400

600

800

1000

0 10 20 30 40

CKMB ng/ml

De

lta f

req

ue

ncy

(H

z).

Conclusions

• Appropriate technology– Portable– Rapid– Low power consumption– Sample handling– Sensitive – appropriate concentration range– Low cost

http://www.biosensingtech.co.uk/

Thank you for your attention.

Are there any questions?

biology for sensors and sensors for biology