Filterless time-domain detection of one or more fluorophores

Patent metadata

Field	Value
Publication number	US-9606060-B2
Application number	US-201313740112-A
Country	US
Kind code	B2
Filing date	Jan 11, 2013
Priority date	Jan 13, 2012
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A device and method are described in which the lifetime of a fluorescent species or fluorophores is detected in the absence of any optical filter. Based on the measured fluorescent lifetimes, molecules or compounds attached to a fluorophores such as small organic molecules, polymers, peptides, saccharides and nucleic acids can be identified or assayed.

First claim

The invention claimed is:

1. A filterless detection system for fluorescent chemical species, comprising
a light emitting device (LED) configured to emit light at a wavelength in correspondence of an excitation wavelength of a fluorescent chemical species;
a photodetector (PD) configured to detect light at a wavelength in correspondence of an emission wavelength of the fluorescent chemical species;
a control circuit configured to enable or disable the LED and the PD independently of each other;
a signal processing circuit, operatively connected with the PD and configured to generate time varying signals as a function of the output of the PD, the time varying signals being indicative of the fluorescent chemical species; and
a sample chamber comprising an array of detection wells,
wherein the filterless detection system is devoid of any optical filter elements.

2. The detection system of claim 1 , wherein the control circuit further comprises:
a controlled time delay device to control a time delay between enabling of the LED and disabling of the PD, or between disabling of the LED and enabling of the PD.

3. The detection system of claim 2 , wherein the controlled time delay device comprises one or more of: a) one or more transistors, b) one or more transistors with one or more delaying capacitors, and c) wires with controlled trace length.

4. The detection system of claim 2 , wherein the control circuit comprises a transistor to control the LED.

5. The detection system of claim 2 , wherein the control circuit comprises transistors and a transistor to control the PD.

6. The detection system of claim 2 further comprising a shunting circuitry configured to shunt away from the signal processing circuit a photocurrent generated by the PD in response to a detected light emitted by the fluorescent chemical species.

7. The detection system of claim 6 wherein the shunting circuitry comprises one or more transistors.

8. The detection system of claim 1 further comprising a shunting circuitry configured to shunt away from the signal processing circuit a photocurrent generated by the PD in response to a detected light emitted by the fluorescent chemical species.

9. The detection system of claim 1 , wherein a controlled detection is performed in the absence of light emitted from the LED.

10. The detection system of claim 9 , wherein during the controlled detection, the signal processing circuit is configured to generate a first voltage proportional to a photocurrent generated by the PD in response to a detected light emitted by the fluorescent chemical species and add the first voltage to a second voltage stored within the signal processing circuit.

11. The detection system of claim 10 , wherein the second voltage is in correspondence of photocurrent generated during one or more controlled detection cycles.

12. The detection system of claim 11 , wherein the signal processing circuit further comprises a reset circuitry to zero a value of the second voltage.

13. The detection system of claim 11 , wherein the signal processing circuit comprises a diode, wherein the diode is in a series connection with a capacitor is used to generate the first voltage and store the second voltage.

14. The detection system of claim 13 , wherein the reset circuitry comprises a transistor operatively coupled to terminals of the capacitor and configured to discharge the capacitor when activated.

15. The detection system of claim 10 , wherein the signal processing circuit comprises an integrator.

16. The detection system of claim 1 , further comprising a microfluidic connector connected to the sample chamber.

17. The detection system of claim 1 , wherein the detection system is used in medical or laboratory diagnostic detection.

18. The detection system of claim 1 , wherein the detection system is used in qPCR, in RT-PCR, sequencing reactions, FRET, FACS, cell imaging, or to quantify the fluorescently labeled molecule.

Assignees

• California Inst Of Techn

Inventors

• Chen Samson
• Rajagopal Aditya
• Scherer Axel

Classifications

• G01N21/6408

  with measurement of decay time, time resolved fluorescence · CPC title

• G01N21/6486 Primary

  Measuring fluorescence of biological material, e.g. DNA, RNA, cells (G01N21/6428 takes precedence) · CPC title