Trenched sample assembly for detection of analytes with electromagnetic read-write heads

Patent metadata

Field	Value
Publication number	US-9304130-B2
Application number	US-97083710-A
Country	US
Kind code	B2
Filing date	Dec 16, 2010
Priority date	Dec 16, 2010
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

Described are embodiments of an invention for a sample assembly with trenches for detection of analytes with electromagnetic read heads. The sample assembly includes an outer layer with at least one sample trench. The sample trench includes a first set of antibodies that are bonded on a first surface of a base layer. Target antigens are bonded with the first set of antibodies, and a second set of antibodies are bonded to the target antigens. Further, the sample trench includes nanoparticles that are bonded to the second set of antibodies. A head module includes a write head for magnetizing nanoparticles and a read sensor for detecting the magnetized nanoparticles, and thus, the target antigens. The sample trench constrains the biological sample, and thus the target antigen, during the preparation and subsequent analysis of the biological sample. Accordingly, the target antigen is aligned with read elements of a head module such that the target antigen is reliably and accurately detected. Further, to ensure reliable and accurate detection, the outer layer is formed with a low friction material allowing the read head to remain in contact with the upper surface of the outer layer during the process of detection.

First claim

What is claimed is:

1. A method of forming a sample assembly of a biological sample having target antigens, the method comprising:
forming a base layer on a substrate;
forming an outer layer on the base layer;
forming at least one sample trench within the outer layer using one or more of a milling technique and a lithography technique, wherein said sample trench has a bottom surface;
forming a plurality of magnetic servo alignment marks on said sample assembly;
bonding a first set of antibodies within said at least one sample trench on a first surface of said base layer;
exposing said at least one sample trench with said first set of bonded antibodies to said biological sample having said target antigens, wherein said target antigens bond with said first set of antibodies within said at least one sample trench;
bonding a second set of antibodies to nanoparticles; and
exposing said target antigens within said at least one sample trench to said second set of antibodies bonded to said nanoparticles,
wherein said second set of antibodies bond with said target antigens within said at least one sample trench.

2. The method of claim 1 , further comprising applying a voltage to the substrate.

3. The method of claim 2 , wherein applying the voltage to the substrate reduces a temperature of the substrate.

4. The method as recited in claim 2 , wherein applying the voltage causes a temperature of the substrate to reduce to a value less than a freezing point of at least one biological sample in the sample trench.

5. The method as recited in claim 4 , wherein the substrate is a Peltier substrate, and wherein the voltage is a DC voltage.

6. The method of claim 1 , further comprising:
forming at least one servo alignment trench in said outer layer, parallel to said sample trench,
filling said servo alignment trench with tape ink;
curing said tape ink; and
forming said plurality of magnetic servo alignment marks in said cured tape ink.

7. The method of claim 1 , further comprising:
magnetizing said nanoparticles using a write head;
aligning the write head with the at least one sample trench using a position-error-servo (PES) technique; and
detecting said magnetized nanoparticles using a read sensor.

8. The method of claim 1 , wherein said outer layer comprises a compound selected from the group consisting of diamond-like-carbon, polytetrafluoroethylene, and aluminum oxide
wherein said first set of antibodies are bonded to said target antigen via a bonding material selected from the group consisting of amide, alkoxysilane, organic functional trialkoxysilane, and thiol.

9. The method of claim 1 , wherein the nanoparticles comprise a plurality of nanoparticles types, each nanoparticle type being characterized by a unique coercivity value,
wherein each nanoparticle type is configured to facilitate detection a different type of target antigen on the sample assembly simultaneously.

10. The method of claim 1 , wherein the at least one sample trench comprises a plurality of parallel-oriented sample trenches, each sample trench being separated from one or more adjacent sample trenches by a distance of approximately 166 microns, and
wherein the at least one sample trench is characterized by a depth in a range from about 0.2 microns to about 60 microns.

11. The method of claim 1 , wherein the bonding the first set of antibodies comprises
coating the first surface of the base layer with one or compounds selected from a group consisting of: amides, alkoxysilanes, and thiols;
contacting a solution of the first set of antibodies with the first surface of the base layer; and
rocking the first surface of the base layer in contact with the solution of the first set of antibodies for a predetermined period of time less than or equal to about six hours.

12. The method as recited in claim 1 , wherein the nanoparticles comprise:
a magnetic inner core comprising a material selected from a group consisting of: CrO 2 , BaFe, and MFe 2 O 4 , wherein M is a metal selected from a group consisting of Co, Cr, Ti, Ba and Mg; and
a shell comprising a material selected from a group consisting of nonmagnetic gold, silicon and silicon dioxide.

13. The method as recited in claim 1 , further comprising:
aligning one or more write elements and one or more read sensors of a head module along an X-axis of the at least one sample trench using at least some of the servo-alignment marks;
coating the first surface of the base layer with one or compounds selected from a group consisting of: amides, alkoxysilanes, and thiols;
contacting a solution of the first set of antibodies with the coated first surface of the base layer;
rocking the coated first surface of the base layer in contact with the solution of the first set of antibodies for a predetermined period of time less than or equal to about six hours; and
magnetizing said nanoparticles using a write head of the head module;
wherein the nanoparticles comprise:
a magnetic inner core comprising a material selected from a group consisting of: CrO 2 , BaFe, and MFe 2 O 4 , where M is a metal selected from a group consisting of Co, Cr, Ti, Ba and Mg; and
a shell comprising a material selected from a group consisting of gold, silicon and silicon dioxide; and

wherein the tape ink comprises magnetic recording particles disposed in a polymer matrix,
wherein the at least one sample trench comprises a plurality of parallel-oriented sample trenches,
wherein the outer layer comprises a compound selected from the group consisting of diamond-like-carbon, polytetrafluoroethylene, and aluminum oxide, and
wherein the first set of antibodies are bonded to said target antigen via a bonding material selected from the group consisting of amide, alkoxysilane, organic functional trialkoxysilane, and thiol.

14. A method of detecting target antigens in a biological sample using
a sample assembly having
a base layer formed above a substrate;
an outer layer formed above the base layer;
at least one sample trench formed in the outer layer using a milling technique;
a plurality of first antibodies, at least some of the first antibodies each being bound to:
at least one surface of one or more of the sample trenches; and
one of a plurality of target antigens;
a plurality of second antibodies, at least some of the second antibodies each being bound
a target antigen bound to one of the first antibodies; and
a nanoparticle,
the method comprising:
aligning a head module with said sample trench utilizing a plurality of magnetic servo alignment marks
sweeping said head module over said sample assembly, wherein said head module includes at least one magneto-resistive read sensor configured to detect target antigens via the nanoparticles; and
detecting at least one particular antigen among the plurality of target antigens.

15. The method of claim 14 , wherein said step of sweeping said head module over said sample assembly includes placing said head module in contact with an upper surface of said outer layer, wherein at least one magneto-resistive read sensor in said head module detects said target antigens in said sample trench.

16. The method of claim 14 , further comprising utilizing a plurality of magnetic servo alignment marks on said sample assembly to align said at least one magneto-resistive read sensor with said sample trench.

17. The method of claim 14 , said head module further comprising at least one write head configured to magnetize the nanoparticles.

18. The method of claim 14 , said head module further comp

Assignees

• Boday Dylan J
• Schwartz Stephen L
• Topol Anna Wanda
• Waters Sandra L
• Winarski Daniel J
• IBM

Inventors

• Boday Dylan J
• Schwartz Stephen L
• Topol Anna Wanda
• Waters Sandra L
• Winarski Daniel J

Classifications

• G01N33/54333 Primary

  Modification of conditions of immunological binding reaction, e.g. use of more than one type of particle, use of chemical agents to improve binding, choice of incubation time or application of magnetic field during binding reaction · CPC title

• B82Y15/00

  Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors · CPC title

• G01N33/543

  with an insoluble carrier for immobilising immunochemicals · CPC title

• G01N33/54366

  Apparatus specially adapted for solid-phase testing · CPC title

• G01N33/54346

  Nanoparticles · CPC title