Thermochromic sensing for nanocalorimetry

Patent metadata

Field	Value
Publication number	US-2017191881-A1
Application number	US-201514984754-A
Country	US
Kind code	A1
Filing date	Dec 30, 2015
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

A nanocalorimeter device includes a substrate having test cells, each test cell comprising a sample location. Each sample location includes a reaction surface suitable for an enthalpic reaction of constituents of liquid droplets, droplet movement and configured to merge the droplets, and a layer of thermochromic material thermally coupled to the reaction surface. The thermochromic material is configured to exhibit a spectral shift in light emanating from the thermochromic material in response to a change in temperature of the merged droplets.

First claim

1 . A nanocalorimeter device comprising:
a substrate having test cells, each test cell comprising a sample location comprising:
a reaction surface suitable for an enthalpic reaction of constituents of liquid droplets;
one or more droplet movement features configured to merge the droplets; and
a layer of thermochromic material thermally coupled to the liquid droplets, wherein light emanating from the thermochromic material exhibits a spectral shift in response to a change in temperature of the liquid droplets.

2 . The device of claim 1 , wherein each test cell further comprises a reference location comprising a surface suitable to receive reference droplets, one or more droplet movement features, and a layer of thermochromic material thermally coupled to the reference droplets.

3 . The device of claim 1 , wherein the substrate is at least partially transparent to the light emanating from the thermochromic material.

4 . The device of claim 1 , wherein the droplet movement features are at least partially transparent to the light emanating from the thermochromic material.

5 . The device of claim 1 , wherein the droplet movement features comprise a first electrode and a second electrode spaced apart from the first electrode.

6 . The device of claim 1 , wherein the droplet movement features comprise an optically controlled surface structure.

7 . The device of claim 1 , wherein at least one of a surface of, a coating on, and a modified surface layer of the thermochromic material comprises the reaction surface.

8 . The device of claim 1 , wherein the thermochromic material is disposed between the reaction surface and the droplet movement features.

9 . The device of claim 1 , further comprising a hydrophobic layer disposed at least at the reaction surfaces of the test locations.

10 . The device of claim 9 , wherein the hydrophobic layer is at least partially transparent to the light emanating from the thermochromic material

11 . The device of claim 1 , wherein the thermochromic layer is disposed between the droplet movement features and the substrate.

12 . The device of claim 1 , wherein the thermochromic layer is on an opposite surface of the substrate from the reaction surface.

13 . The device of claim 1 , wherein the droplet movement features of location are disposed within a thermal equilibration region.

14 . The device of claim 13 , wherein the thermal equilibration region comprises a thermally conductive component.

15 . The device of claim 14 , wherein the thermally conductive component is at least partially transparent to the light emanating from the thermochromic layer.

16 . The device of claim 14 , wherein the thermally conductive component is between the thermochromic layer and the substrate.

17 . The device of claim 16 , wherein the thermally conductive component is at least partially transparent to the light emanating from the thermochromic layer.

18 . The device of claim 1 , further comprising a barrier layer disposed over the substrate and the barrier layer is at least partially transparent to the light emanating from the thermochromic layer.

19 . The device of claim 1 , wherein the thermochromic material comprises one or more of thermochromic liquid crystals, leuco dye, a fluorophore, Prodan bound to DPPC, or a fluorescent protein.

20 . The device of claim 1 , wherein the light emanating from the thermochromic material is configured to exhibit a spectral shift as a function of temperature in a range of about 0.5 nm/K to about 1000 nm/K.

21 . The device of claim 1 , further comprising a magnetic droplet mixing material disposed at each of the locations, the droplet mixing material configured to mix the droplets after merging.

22 . The device of claim 1 , further comprising a surface structure that can be optically altered to mix the droplets after merging.

23 . The device of claim 1 , further comprising a cap having at least one cavity that is positioned above and in contact with an upper surface of the device, the cap forming a seal around one or more of the test cells.

24 . A system comprising:
a substrate having one or more sample locations, each sample location comprising:
a reaction surface disposed over the substrate, the reaction surface suitable for an enthalpic reaction of constituents of liquid droplets;
one or more droplet movement layers disposed between the reaction surface and the substrate; and
a layer of thermochromic material thermally coupled to the droplets, light emanating from the thermochromic layer exhibiting a spectral shift in response to a change in temperature of the droplets; and
one or more sensors, each sensor configured to sense the light emanating from the thermochromic layer at one or more of the locations and to generate an electrical signal in response to the sensed light, the electrical signal including information about the spectral shift.

25 . The system of claim 24 , further comprising an analyzer configured to receive electrical signals from the sensors and to determine a presence and/or amount of the spectral shift in the light emanating from the thermochromic material based on the electrical signals.

26 . The system of claim 25 , wherein the analyzer is configured to detect the spectral shift based on a difference between light emanating from the thermochromic layer at a sample location and light emanating from the thermochromic layer at a reference location paired with the sample location.

27 . The system of claim 24 , wherein the spectral shift in the light emanating from the thermochromic layer comprises a spectral shift in at least one of scattered, reflected, transmitted, and fluorescent light emanating from the thermochromic material.

28 . The system of claim 24 , further comprising a light source configured to emit measurement light, wherein the light emanating from the thermochromic layer is in response to measurement light that interacts with the thermochromic material.

29 . The system of claim 24 , further comprising:
a droplet mixing material positioned at each of the locations; and an energy source configured to move the droplet mixing material.

30 . A method comprising:
depositing a first liquid droplet and a second liquid droplet on a surface at a sample location with a spacing between the first liquid droplet and the second liquid droplet; thermally equilibrating the first and second droplets; merging the first and second droplets; and detecting a spectral shift in light emanating from thermochromic material thermally coupled to the merged droplets in response to an enthalpic reaction of the merged droplets.

31 . The method of claim 30 , further comprising mixing the first and second droplets after the merging.

32 . The method of claim 30 , wherein the location is a sample location, and further comprising:
depositing a third liquid droplet and a fourth liquid droplet on the surface at a reference location with a spacing between the third liquid droplet and the fourth liquid droplet, the third and fourth droplets similar in composition and volume to the first and second droplets and lacking reacting constituents present in the first and second droplets; thermally equilibrating the third and fourth droplets; merging the third and fourth droplets; and

Assignees

• Palo Alto Res Ct Inc

Inventors

• Kiesel Peter
• Martini Joerg
• Recht Michael I

Classifications

• G01K17/006 Primary

  Microcalorimeters, e.g. using silicon microstructures · CPC title

• G01K11/165 Primary

  of organic liquid crystals · CPC title

• G01K11/12

  using changes in colour, translucency or reflectance · CPC title