Time resolved optical array detectors and CCD cameras for frequency domain fluorometry and/or phosphorimetry

• US 5,323,010 A
• Filed: 12/01/1992
• Issued: 06/21/1994
• Est. Priority Date: 12/01/1992
• Status: Expired due to Fees

• Current Assignee: ISS
• Original Assignee: ISS
• Inventors: VandeVen, Martin, Gratton, Enrico, Barbieri, Beniamino
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US07/983,829
• Time in Patent Office: 567 Days
• Field of Search: 250/461.1, 250/459.1, 250/458.1
• US Class Current: 250/458.1
• CPC Class Codes: G01J 3/4406 Fluorescence spectrometry
• CPC Class Codes: G01N 2021/1772 Array detector
• CPC Class Codes: G01N 2021/1789 Time resolved
• CPC Class Codes: G01N 21/6408 with measurement of decay time, time resolved fluorescence

Abstract

An apparatus for cross-correlation frequency domain fluorometry-phosphorimetry comprises a source of electromatic radiation and means for amplitude modulating the radiation at the first frequency. The amplitude modulated radiation is directed at a sample, while an optical array detector measures the resulting luminescence of the sample. A signal is provided coherent with the amplitude modulated electromagnetic radiation signals, at a second frequency which is different from the first frequency. The apparatus has the capability for shutting off and turning on the coherent signal at the second frequency in a cycle which is at a third frequency that is different from the difference between the first and second frequencies. This produces a resultant signal at a frequency derived from the difference and the third frequency. The resultant signal, when turned on, modulates the gain of the detecting means or multiplies its output, depending upon the nature of the detecting means. The amount of luminescence measured by the optical array detector is read when the coherent signal is off in its cycle of the third frequency. A signal from the reader described above is then detected at a frequency of the resultant signal to determine phase shift and modulation changes of the luminescence.

Claims

1. An apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:

a source of electromagnetic radiation;

means for amplitude modulating the electromagnetic radiation at a first frequency;

means for directing the amplitude-modulated electromagnetic radiation at a sample;

optical array detector means for detecting the luminescence of the sample;

means for providing a signal coherent with amplitude modulated signals produced by said amplitude modulating means, at a second frequency, said second frequency being different from said first frequency;

means for shutting off and turning on said coherent signal providing means in a cycle having a third frequency that is different from the difference between the first and second frequencies, to produce a resultant signal at a frequency derived from said difference and said third frequency;

means for modulating the gain of said detecting means, or multiplying the output of said detecting means, by said resultant signal;

means for reading the amount of luminescence detected by said optical array detector means when said coherent signal providing means is off in its cycle of said third frequency; and

second means for detecting a signal from said reading means at a frequency of said resultant signal to determine phase shift and modulation changes of said luminescence.

2. The apparatus of claim 1 in which the frequency of said resultant signal is about 1-10 Hz.

3. The apparatus of claim 1 in which said optical array detector means comprises a microchannel plate intensifier linked with a diode array detector.

5. The apparatus of claim 1 in which said first frequency is essentially 100 hertz to 300 megahertz.

6. The apparatus of claim 1 in which said resultant signal frequency is no more than about one quarter of the frequency difference between the first and second frequencies.

7. The apparatus of claim 1 in which said resultant signal frequency derived from said frequency difference and said third frequency by subtraction.

4. The apparatus of claim in which the difference between the first and second frequencies is essentially 6-40 Hz.

8. An apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:

a source of electromagnetic radiation;

means for amplitude modulating the electromagnetic radiation at a first frequency;

means for directing the amplitude-modulated electromagnetic radiation at a sample;

an image intensifier having a photocathode and a microchannel plate intensifier to amplify the luminescence of the sample;

an optical array detector for detecting the amplified luminescence of the sample;

means for providing a signal coherent with amplitude modulated signals produced by said amplitude modulating means, at a second frequency, said second frequency being different from said first frequency;

means for shutting off and turning on said coherent signal providing means in a cycle having a third frequency that is different from the difference between said first and second frequencies.

means to direct said second frequency signal to the photocathode of the image intensifier;

means for producing a signal equal in frequency to said third signal to the input of the microchannel plate intensifier to modulate the gain of the image intensifier and produce a resultant signal at a frequency derived from said frequency difference and said third frequency;

means for reading the amount of luminescence detected by said optical array detector when said coherent signal providing means is off in its cycle of aid third frequency; and

second means for detecting a signal from said reading means at a frequency of said resultant signal to determine phase shift and modulation changes of said luminescence.

9. The apparatus of claim 8 in which the frequency of said resultant signal is about 1-10 Hz.

10. The apparatus of claim 8 in which said optical array detector means comprises a CCd and/or CID camera detector with image intensifier.

11. The apparatus of claim 8 in which the difference between the first and second frequencies is essentially 6-40 Hz.

12. The apparatus of claim 8 in which said first frequency is essentially 100 hertz to 300 megahertz.

13. The apparatus of claim 8 in which said resultant signal frequency is of no more than about one quarter of the frequency difference between the first and second frequencies.

14. The apparatus of claim 13 in which said resultant signal is at a frequency derived form said frequency difference and said third frequency by subtraction.

15. An apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:

a pulsed source of electromagnetic radiation having a first pulsation frequency;

means for directing the pulsed electromagnetic radiation at a sample;

an image intensifier having a photocathode and a microchannel plate intensifier to amplify the luminescence of the sample;

an optical array detector for detecting the luminescence of the sample;

means for providing a signal coherent with pulsed signals produced by said pulsed source of electromagnetic radiation at a second frequency, said second frequency being different from said first frequency;

means for shutting off and turning on said coherent signal providing means at the second frequency in a cycle having a third frequency that is different from the difference between the first and second frequencies;

means to direct said second frequency signal to the photocathode of the image intensifier;

means for producing a signal equal in frequency to said third signal to the input of the image intensifier to modulate the gain of the image intensifier and produce a resultant signal at a frequency derived from said frequency difference and said third frequency;

means for reading the amount of luminescence detected by said optical array detector when said coherent signal providing means is off in its cycle of said third frequency; and

second means for detecting a signal from said reading means at a frequency of said resultant signal to determine phase shift and modulation changes of said luminescence.

16. The apparatus of claim 15 in which said first frequency is essentially 100 hertz to 300 megahertz.

17. The apparatus of claim 15 in which the difference between the first and second frequencies is essentially 6-40 Hz.

18. The apparatus of claim 15 in which said optical array detector means comprises a CCD and/or CID camera detector with image intensifier.

19. The apparatus of claim 15 in which the frequency of said resultant signal is about 1-10 Hz.

20. The apparatus of claim 15 in which the resultant signal is at a frequency derived from said frequency difference and said third frequency by subtraction.