Phase fluorometry using a modulated electroluminescent lamp as a light source
AssigneeUniversity of Maryland, School of Medicine
InventorsKlaus W. Berndt, Joseph R. Lakowicz
Life of this patent
Estimating the term…
Abstract
A method and apparatus for using a square wave- or sinewave-driven electroluminescent lamp (ELL) as a source of periodically pulsed excitation light for a luminescent molecule, wherein changes in decay time, phase angle and/or modulation of the emitted luminescence are detected as parameters that correspond to changes in luminescence lifetimes.
Claims55
An apparatus for detecting a change in decay time, phase angle and/or modulation, corresponding to a change in a lifetime, of a luminescence emission of at least one luminescent molecule comprising:
- an electroluminescent lamp which outputs modulated light when driven by a first electrical signal;
- a first electrical signal generator, coupled to said electroluminescent lamp, for generating said first electrical signal to cause said electroluminescent lamp to output said modulated light having a wavelength which excites said at least one luminescent molecule to produce said luminescence emission;
- a photosensor for detecting said luminescence emission and generating a second electrical signal corresponding to said luminescence emission;
- a meter coupled to said photosensor and said first electrical signal, wherein said meter compares said first electrical signal to said second electrical signal to provide said change in decay time, phase angle and/or modulation of said luminescence emission of said at least one luminescent molecule, wherein said change corresponds to said change in a luminescence lifetime of said luminescent molecule.
A method of using an electroluminescent lamp as a high-frequency modulated light source, comprising detecting a change in decay time, phase angle and/or modulation, corresponding to a change in a lifetime of a luminescence emission of at least one luminescent molecule.
A method for detecting a change in decay time, phase angle and/or modulation, corresponding to a change in a lifetime, of a luminescence emission of at least one luminescent molecule comprising:
- driving an electroluminescent lamp with a first electrical signal to cause said electroluminescent lamp to output modulated light having a wavelength which excites said at least one luminescent -molecule in a sample to produce said luminescence emission;
- exciting said at least one luminescent molecule with said modulated light to produce a luminescence emission;
- detecting said luminescence emission with a photosensor to produce a second electrical signal corresponding to said luminescence emission;
- comparing said first electrical signal to said second electrical signal to provide said change in decay time, phase angle and/or modulation of said luminescence emission of said at least one luminescent molecule, wherein said change corresponds to said change in a luminescence lifetime of said luminescent molecule.
An apparatus for measuring luminescence comprising:
- an electroluminescent lamp (ELL) which produces light when driven by an electrical input signal;
- an electrical input signal generator, coupled to said ELL, for generating an electrical input signal which drives said ELL;
- at least one luminescent molecule for determining a condition and emitting a characteristic luminescence upon incidence of light output from said ELL;
- and
- light-detecting means for detecting the lifetime of said luminescence as a measurement of said condition.
A method of continuously generating light pulses from an electroluminescent lamp (ELL) having a luminescence material disposed between electrodes, said method comprising:
- continuously applying a square wave input voltage signal to said electrodes of said ELL;
- and
- rapidly and continuously alternating the polarity of the voltage of said square wave input signal so that said luminescence material continuously generates a corresponding pulsed light output waveform.
An apparatus for measuring luminescence comprising:
- an electroluminescent lamp (ELL) which outputs pulses of light when driven by an amplitude-modulated electrical input signal;
- an electrical input signal generator, electrically coupled to said ELL, for generating a square-wave electrical input signal whose transition time from a positive voltage to a negative voltage is less than or equal to 1 .mu.s, so that the light pulses have a repetition frequency which is a harmonic of twice the modulation frequency of said electrical input signal;
- a chemical sensor for determining a condition and emitting luminescence upon incidence of the light output from said ELL;
- and
- light-detecting means for detecting said luminescence as a measurement of said condition.
A method of measuring luminescence, comprising the steps of:
- driving an electroluminescent lamp (ELL) with an alternating input voltage signal whose transitions from a positive voltage to a negative voltage cause the ELL to output pulses of light;
- exciting a luminescent molecule with the pulses of light from the ELL;
- and
- detecting resulting emitted luminescence radiation from the luminescent molecule.
An apparatus for generating light pulses, comprising:
- an electroluminescent lamp having a luminescence material disposed between two electrodes;
- and
- means for applying across said electrodes a square wave voltage signal that continuously alternates in polarity at a frequency of at least 500 Hz to cause said lamp to generate a correspondingly continuous train of periodic light pulses each of which has a full width at half maximum (FWHM) of at least as short as 1 .mu.sec.
Dependencies are inferred from the claim text.