NANO-POROUS MEMBRANE BASED SENSORS

• US 20130224765A1
• Filed: 04/02/2013
• Published: 08/29/2013
• Est. Priority Date: 12/02/2005
• Status: Active Grant

• Current Assignee: State Of Oregon Acting By And Through The State Board Of Higher Education On Behalf Of Portland State University
• Original Assignee: German University, Oregon State University (Oregon University System)
• Inventors: Prasad, Shalini, Kondama Reddy, Ravi Kiran
• Granted Patent: US 9,222,907 B2
• Time in Patent Office: Days
• US Class Current: 435/7.4
• CPC Class Codes: G01N 27/26 by investigating electrochemical variables; by using electrolysis or electrophoresis
• CPC Class Codes: G01N 27/3278 involving nanosized elements, e.g. nanogaps or nanoparticles nanopores G01N33/48721; magnetic beads G01N27/745

Abstract

Sensors include nano-porous alumina membranes that are sensitized by immobilization of antibodies in the nano-pores. The nano-membranes can be sensitized to respond to a single target compound, or different portions of the nano-membrane can be differently sensitized. Capture of the target compound can be detected based on a spectral signature associated with electrical conductance in the nano-pores.

Claims

1. A sensor, comprising:

a solid substrate having a top surface;

a nano-porous alumina membrane situated at the top surface of the solid substrate, the alumina membrane including a plurality of nano-pores, the alumina membrane including a first sensitizing agent for detection of a target compound, the first sensitizing agent being immobilized within a first set of nano-pores so as to define a sensitized portion of the alumina membrane; and

a first conductor electrically coupled to the first sensitizing agent immobilized in the first set of nano-pores defined in the alumina membrane, the first conductor situated on the top surface of the solid substrate and in contact with the sensitized portion of the alumina membrane.

2. The sensor of claim 1, further comprising:

a second conductor electrically coupled to a second set of nano-pores; and

a second sensitizing agent immobilized within the second set of nano-pores.

3. The sensor of claim 2, wherein the first sensitizing agent and the second sensitizing agent are the same.

4. The sensor of claim 2, wherein the first sensitizing agent and the second sensitizing agent are different.

5. The sensor of claim 1, further comprising a spectrum analyzer in communication with the first conductor, the spectrum analyzer configured to produce an estimate of a received signal portion based on a signature frequency or frequencies associated with specific binding of a target compound to the first sensitizing agent.

6. The sensor of claim 5, wherein the spectrum analyzer is configured to produce an estimate of a received signal portion associated with at least two frequencies associated with a detection signature.

7. The sensor of claim 2, further comprising a spectrum analyzer that is selectively coupled to the first conductor and the second conductor, wherein the spectrum analyzer is configured to produce an estimate of a received signal portion associated with a frequency or frequencies associated with a first signature and a frequency or frequencies associated with a second signature.

8. The sensor of claim 5, wherein the spectrum analyzer is configured to produce an estimate of a received signal portion associated with at least two frequencies associated with the first signature and the second signature.

9. The sensor according to claim 1 further comprising a signature analyzer electrically coupled to the first conductor and configured to estimate a target compound concentration based on at least one signature portion associated with specific binding of the target compound to the sensitizing agent within the first set of nano-pores.

10. The sensor of claim 9, wherein the signature portion is a signal magnitude in a selected frequency range.

11. The sensor of claim 9, further comprising a signature database, and the signature analyzer is configured to produce an indication of a presence of at least one target compound based on a comparison of the at least one signature portion associated with specific binding of the target compound by the sensitizing agent with at least one stored signature associated with specific binding.

12. An apparatus, comprising:

a base substrate having a plurality of conductor segments defined thereon;

a nano-porous membrane secured to the base substrate, the nano-porous membrane including a plurality of sets of sensitized nano-pores, the nano-pores having respective sensitizers for detection of a target compound, the sensitizers being immobilized within the sets of nano-pores, and the respective sensitizers electrically coupled to corresponding conductor segments; and

a fluid chamber configured to receive a test fluid and communicate the test fluid to the sets of sensitized nano-pores.

13. The apparatus of claim 12, wherein the nano-porous membrane is an alumina membrane having a plurality of nano-pores with effective diameters in a range of 5 nm to 500 nm.

14. The apparatus of claim 13, wherein the plurality of sets of nano-pores comprises a first set of nano-pores having a first effective diameter, and a second set of nano-pores having a second effective diameter, and wherein the first effective diameter is larger than the second effective diameter.

15. The apparatus of claim 12, further comprising a spectrum analyzer configured to receive electrical signals from the conductor segments and produce spectra of the electrical signals.

16. A method, comprising:

administering a test specimen to sensor comprising a solid substrate having a top surface, a nano-porous alumina membrane situated at the top surface of the solid substrate, the alumina membrane including a plurality of nano-pores, the alumina membrane including a first sensitizing agent for detection of a target compound, the first sensitizing agent being immobilized within a first set of nano-pores so as to define a sensitized portion of the alumina membrane, and a first conductor electrically coupled to the first sensitizing agent immobilized in the first set of nano-pores defined in the alumina membrane, the first conductor situated on the top surface of the solid substrate and in contact with the sensitized portion of the alumina membrane;

evaluating an electrical signal associated with administration of the test specimen to the sensor; and

assessing the test specimen based on the evaluation.

17. The method of claim 16, wherein the electrical signal is evaluated to identify a magnitude of at least one electrical spectral peak associated with exposure of the sensor to the target compound, and the test specimen is assessed based on the magnitude.

18. The method of claim 16, wherein the test specimen is administered to an sensor sensitized to at least a first target compound and a second target compound.

19. The method of claim 18, wherein the first target compound is CRP and the second target compound is MPO.

20. The method of claim 16, wherein the target compound is prostate specific antigen.