Digital Microfluidic (DMF) Devices, Systems, and Methods for Spectrochemical Analysis
Described is a digital microfluidics system and method for measuring an analyte concentration in a droplet. Droplet movement operations can be used to carry out biological, biochemical, and chemical reactions, measurements, and experiments and a light source and light detector or spectrophotometer can be used to transmit light through a droplet to determine the absorbance of light through the droplet to calculate a concentration of analyte in the droplet.
1 . A digital microfluidic (DMF) device comprising:
an input configured to cause light to be transmitted through a fluid droplet on a surface; and
an output for collecting light transmitted through the fluid droplet on the surface;
wherein the surface is configured to perform one or more droplet operations on the fluid droplet thereby causing a change in a shape of the fluid droplet,
wherein the change in the shape of the fluid droplet alters a path length between the input and the output.
2 . The DMF device of claim 1 , wherein the DMF device is configured to electronically connect to a DMF system comprising:
a light source electronically connected to the input for providing light to the input;
a detector electronically connected to the output for receiving light from the output; and
a controller electronically connected to the surface, the light source, and the detector, wherein the controller is configured to:
cause the surface to perform the one or more droplet operations on the fluid droplet thereby altering the path length between the input and the output;
cause the light source to transmit light to the input;
cause the detector to receive light from the output;
process a signal generated by the detector in response to receiving the light from the output; and
generate a spectrum based on the signal generated by the detector.
3 . The DMF device of claim 2 , wherein the spectrum generated by the controller is proportional to the path length.
4 . The DMF device of claim 3 , wherein either the input, the output, or both the input and the output is an optical guide.
5 . The DMF device of claim 4 , wherein the optical guide is selected from: a lens, a mirror, an optical fiber, or a fenestration.
6 . The DMF device of claim 5 , wherein the optical guide is disposed on or adjacent to the surface.
7 . The DMF device of claim 6 , wherein the optical guide is configured to engagingly contact the fluid droplet.
8 . The DMF device of claim 7 , wherein the optical guide is moveable thereby enabling the optical guide to engagingly contact the fluid droplet.
9 . The DMF device of claim 8 , wherein the change in the shape of the fluid droplet caused by the one or more droplet operations causes the fluid droplet to engagingly contact the optical guide.
10 . The DMF device of claim 1 , wherein the DMF device is configured to electronically connect to a DMF system comprising:
a controller electronically connected to the surface, the input, and the output, wherein the controller is configured to:
cause the surface to perform the one or more droplet operations on the fluid droplet thereby altering the path length between the input and the output;
cause the input to transmit light to through the fluid droplet;
cause the output to receive light transmitted through the fluid droplet;
process a signal generated by the output in response to receiving the light transmitted through the fluid droplet; and
generate a spectrum based on the signal generated by the output.
11 . The DMF device of claim 10 , wherein the spectrum generated by the controller is proportional to the path length.
12 . The DMF device of claim 11 , wherein the input is a light source.
13 . The DMF device of claim 12 , wherein the light source is disposed on or adjacent to the surface.
14 . The DMF device of claim 13 , wherein the light source is configured to engagingly contact the fluid droplet.
15 . The DMF device of claim 14 , wherein the light source is moveable thereby enabling the light source to engagingly contact the fluid droplet.
16 . The DMF device of claim 15 , wherein the change in the shape of the fluid droplet caused by the one or more droplet operations causes the fluid droplet to engagingly contact the light source.
17 . The DMF device of claim 16 , wherein the output is a sensor.
18 . The DMF device of claim 17 , wherein the sensor is disposed on or adjacent to the surface.
19 . The DMF device of claim 18 , wherein the sensor is configured to engagingly contact the fluid droplet.
20 . The DMF device of claim 19 , wherein the sensor is moveable thereby enabling the sensor to engagingly contact the fluid droplet.
21 . The DMF device of claim 20 , wherein the change in the shape of the fluid droplet caused by the one or more droplet operations causes the fluid droplet to engagingly contact the sensor.
22 . The DMF device of claim 21 , further comprising a surface plasmon resonance (SPR) sensor or a localized surface plasmon resonance (LSPR) sensor.
23 . A method for spectrochemical analysis, comprising:
providing a fluid droplet to a surface of a digital microfluidic (DMF) device, the DMF device comprising:
an input configured to cause light to be transmitted through the fluid droplet on the surface; and
an output for collecting light transmitted through the fluid droplet on the surface;
positioning the fluid droplet between the input and the output;
changing a shape of the fluid droplet thereby changing a path length between the input and the output;
transmitting light via the input through the fluid droplet;
collecting light transmitted through the fluid droplet via the output; and
generating a spectrum using the light collected by the output, wherein an intensity of the spectrum is proportional to the path length.