Nano-plasmonic sensor for exosome detection

Patent metadata

Field	Value
Publication number	US-2016334398-A1
Application number	US-201415100997-A
Country	US
Kind code	A1
Filing date	Dec 2, 2014
Priority date	Dec 2, 2013
Publication date	Nov 17, 2016
Grant date	—

Abstract

Disclosed herein are compositions and methods for exosome detection with high sensitivity by using a nano-plasmonic sensor. The nano-plasmonic sensor comprises a plurality of nanoapertures suitable for transmission measurements. The detection sensitivity is on the order of 10 4 -fold higher than western blotting and 10 2 -fold higher than enzyme-linked immunosorbent assay (ELISA). A portable imaging system is also disclosed, enabling rapid and high-throughput detection of exosomes. The nano-plasmonic sensor and imaging system can be useful in diagnostics.

First claim

1 . A nano-plasmonic sensor for detecting exosomes comprising,
a) a transparent planar substrate; b) a metal film disposed onto one surface of the substrate, wherein the metal film comprises a plurality of nanoapertures in a predefined pattern to create a sensing area that produces surface plasmon resonance upon illumination; and c) a capture agent attached to the metal film, wherein the capture agent specifically binds to an exosome marker.

2 . The nano-plasmonic sensor of claim 1 , further comprising a molecular spacer directly attached to the metal film, and a linking agent directly attached to the molecular spacer and directly attached to the capture agent.

3 . The nano-plasmonic sensor of claim 1 , wherein the metal film comprises a noble metal, a transition metal, an alkali metal, or any combination thereof.

4 . The nano-plasmonic sensor of claim 3 , wherein the substrate comprises glass, quartz, diamond, or a polymer.

5 . The nano-plasmonic sensor of claim 4 , wherein the metal film comprises gold and the substrate comprises glass.

6 . The nano-plasmonic sensor of claim 5 , wherein the metal film is between 50 to 500 nm thick.

7 . The nano-plasmonic sensor of claim 6 , further comprising an adhesion layer located between the metal film and the substrate surface.

8 . The nano-plasmonic sensor of claim 7 , wherein the adhesion layer is less than about 50 nm thick.

9 . The nano-plasmonic sensor of claim 8 , wherein the predefined pattern is periodic.

10 . The nano-plasmonic sensor of claim 9 , wherein the nanoapertures have a dimension and periodicity that produce an electromagnetic field with a decay length of about 50 nm to 200 nm when the nanoapertures are illuminated by light with a wavelength close to or at the surface plasmon resonance.

11 . The nano-plasmonic sensor of claim 10 , wherein the nanoapertures are circular, elliptical, rectangular, triangular, oval, or hexagonal.

12 . The nano-plasmonic sensor of claim 11 , wherein the circular nanoapertures are about 50 nm to 300 nm in diameter, and wherein the periodicity is about 400 nm to 700 nm.

13 . The nano-plasmonic sensor of claim 12 , wherein the circular nanoapertures are about 200 nm in diameter, and wherein the periodicity is about 450 nm to 500 nm.

14 . The nano-plasmonic sensor of claim 13 , wherein the molecular spacer comprises polyethylene glycol (PEG).

15 . The nano-plasmonic sensor of claim 14 , wherein the PEG comprises long-chain PEG and short-chain PEG in a ratio of about 1:3.

16 . The nano-plasmonic sensor of claim 15 , wherein the linking agent comprises protein A/G or neutravidin.

17 - 35 . (canceled)

36 . A method of detecting exosomes in a sample, comprising
a) introducing a sample suspected of containing one or more exosomes onto a nano-plasmonic sensor of claim 1 under conditions which promote binding of the exosomes to the sensor; b) washing the sensor to remove unbound materials; c) illuminating the sensor to thereby transmit light through the sensor; d) measuring the light transmitted through the sensor to identify a significant change from that of a negative control; and e) detecting exosomes in the sample when the significant change in the transmitted light is identified.

37 . The method of claim 36 , wherein the negative control is a solution substantially free of exosomes or exosome lysates.

38 . The method of claim 36 , wherein the change is a shift in peak wavelength.

39 - 43 . (canceled)

44 . A method for determining an expression level of a target marker in a sample of exosomes, comprising:
a) detecting total exosomes in the sample by the method of claim 36 , using a capture agent that specifically binds a pan-exosomal marker; b) detecting exosomes in the sample expressing the target marker by the method of claim 36 using a capture agent that specifically binds the target marker; and c) calculating the ratio of exosomes with the target marker to total exosomes to thereby indicate the average expression level of the target marker per exosome from the sample.

45 - 50 . (canceled)

Assignees

• Massachusetts Gen Hospital

Inventors

• Weissleder Ralph
• Lee Hakho
• Im Hyungsoon
• Castro Cesar

Classifications

• G01N33/57545

  of the ovaries · CPC title

• G01N21/554

  detecting the surface plasmon resonance of nanostructured metals, e.g. localised surface plasmon resonance · CPC title

• G01N2021/0346

  Capillary cells; Microcells · CPC title

• G01N21/05

  Flow-through cuvettes (G01N21/09 takes precedence; handling fluid samples G01N1/10) · CPC title

• G01N2333/70596

  Molecules with a "CD"-designation not provided for elsewhere in G01N2333/705 · CPC title