Piezoelectric microcantilever sensors for biosensing

Patent metadata

Field	Value
Publication number	US-9274087-B2
Application number	US-201414551710-A
Country	US
Kind code	B2
Filing date	Nov 24, 2014
Priority date	Nov 28, 2006
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

A piezoelectric microcantilever for sensing compounds or molecules. The piezoelectric microcantilever, may include at least one electrode, an insulation layer, a receptor, an immobilization layer, a non-piezoelectric layer and a piezoelectric layer The sensor is capable of self actuation and detection. The piezoelectric layer may be constructed from a highly piezoelectric thin lead magnesium niobate-lead titanate film, a highly piezoelectric thin zirconate titanate film, a highly piezoelectric lead-free film. Methods of using the sensors and flow cells and arrays including the sensors are also described.

First claim

The invention claimed is:

1. A method for using a piezoelectric microcantilever sensor comprising the steps of:
actuating a microcantilever sensor having a Q value greater than 20, comprising a piezoelectric layer, a non-piezoelectric layer, and a receptor, wherein said piezoelectric layer has a thickness of about 1 μm to about 127 μm, a dielectric constant of at least 1600, and a piezoelectric coefficient −d 31 of at least about 250 pm/V;
binding a molecule or compound to said receptor,
detecting a force exerted on said piezoelectric layer by said bound molecule or compound, and
determining one or more of a presence of said molecule or compound and a concentration of said molecule or compound from said detected force.

2. The method of claim 1 , wherein said receptor is selected from the group consisting of DNA, proteins, enzymes, cells, viruses, parasites, antigens and pathogens.

3. The method of claim 1 , wherein said molecule or compound is selected from the group consisting of bioterrorism agents, cancer agents, bacterial disease agents and viral disease agents.

4. The method of claim 1 , further comprising the step of detecting a resonance frequency shift.

5. The method of claim 1 , wherein the microcantilever sensor further comprises an electrical insulation layer which insulates conducting elements of said sensor.

6. The method of claim 5 , wherein the electrical insulation layer comprises a material selected from the group consisting of poly-para-xylylene, methyltrimethoxysilane, 3-mercaptopropyl trimethoxysilane, Al 2 O 3 , SiO 2 and functionalized hydrophobic silanes and mixtures thereof.

7. The method of claim 1 , wherein the receptor is bound to a conducting element by an immobilization layer.

8. The method of claim 1 , wherein a length of said piezoelectric layer is less than or greater than a length of said non-piezoelectric layer.

9. The method of claim 1 , wherein said piezoelectric layer if fabricated from a freestanding film.

10. The method of claim 1 , wherein said piezoelectric layer has a thickness of less than 2 μm.

11. The method of claim 1 , wherein said piezoelectric layer has a dielectric constant of at least 1900 and a thickness less than 4 μm.

12. The method of claim 1 , wherein said piezoelectric layer has a dielectric constant of at least 1900 and a thickness less than 2 μm.

13. The method of claim 1 , wherein said piezoelectric layer has a thickness less than 8 μm.

14. The method of claim 1 , wherein said piezoelectric layer comprises a material selected from the group consisting of lead magnesium niobate-lead titanate, lead-zirconate-titanate, and doped sodium potassium niobate-lithium niobate.

15. The method of claim 1 , wherein said piezoelectric layer comprises a lead-free piezoelectric material.

16. The method of claim 1 , wherein said piezoelectric microcantilever has a Q value greater than 120.

17. The method of claim 1 , wherein the non-piezoelectric layer comprises a material selected from the group consisting of a ceramic material, a polymeric material, a metallic material and a combinations thereof.

18. The method of claim 1 , wherein said non-piezoelectric layer comprises a material selected from the group consisting of silicon dioxide, silicon nitride, tin and copper.

19. The method of claim 1 , wherein said non-piezoelectric layer comprises multiple layers of different materials.

20. The method of claim 1 , wherein the step of actuating comprises applying a voltage across said piezoelectric layer.

Assignees

• Shih Wan Y
• Shih Wei-Heng
• Shen Zuyan
• Mcgovern John-Paul
• Zhu Qing
• Capobianco Joseph
• Univ Drexel

Inventors

• Shih Wan Y
• Shih Wei-Heng
• Shen Zuyan
• Mcgovern John-Paul
• Zhu Qing
• Capobianco Joseph

Classifications

• G01N2291/0257

  with a layer containing at least one organic compound · CPC title

• G01N33/54306

  Solid-phase reaction mechanisms · CPC title

• B82Y35/00

  Methods or apparatus for measurement or analysis of nanostructures · CPC title

• B82Y5/00

  Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery · CPC title

• G01N33/57515

  of the breast · CPC title