Detection of Microorganisms With a Fluorescence-Based Device

Abstract

A device and method for detecting by fluorescence microbial growth from sample substances are disclosed. For example, a method for the detection of visible-band fluorescence signals generated by at least one fluorescing compound excited by ultraviolet energy, comprising exciting said at least one fluorescing compound with ultraviolet energy emitted from a light-emitting diode comprising wavelengths below 400 nanometers, and detecting a visible-band fluorescence signal generated by said at least one excited fluorescing compound with at least one light detector sensitive to electromagnetic energy comprising wavelengths greater than or equal to 400 nanometers wavelength. For example, a device for detecting visible-band fluorescence signals generated by at least one fluorescing compound excited by ultraviolet energy, comprising at least one ultraviolet light-emitting diode generating electromagnetic radiation comprising wavelengths below 400 nanometers and capable of exciting the at least one fluorescing compound, at least one light detector sensitive to electromagnetic energy comprising wavelengths greater than or equal to 400 nanometers wavelength for the detection of visible-band fluorescence signals generated by the at least one fluorescing compound.

1 . A method for the detection of visible-band fluorescence signals generated by at least one fluorescing compound excited by ultraviolet energy, comprising:
 exciting said at least one fluorescing compound with ultraviolet energy emitted from a light-emitting diode comprising wavelengths below 400 nanometers; and   detecting a visible-band fluorescence signal generated by said at least one excited fluorescing compound with at least one light detector sensitive to electromagnetic energy comprising wavelengths greater than or equal to 400 nanometers.   
     
     
         2 . The method of  claim 1 , wherein said light detector is a photo-transistor with diminished sensitivity below 400 nanometers wavelength. 
     
     
         3 . The method of  claim 1 , wherein said at least one light-emitting diode generates a stationary level of energy. 
     
     
         4 . The method of  claim 1 , wherein said at least one light-emitting diode generates pulsated energy. 
     
     
         5 . The method of  claim 1 , wherein said at least one said fluorescing compound is chosen from umbelliferons and coumarins. 
     
     
         6 . The method of  claim 1 , wherein said at least one fluorescing compound is dissolved in liquid. 
     
     
         7 . The method of  claim 1 , wherein said at least one fluorescing compound is dissolved in agar. 
     
     
         8 . The method of  claim 1 , wherein said at least one fluorescing compound is impregnated in a matrix. 
     
     
         9 . The method of  claim 6 , wherein biological cells are grown in said liquid. 
     
     
         10 . The method of  claim 9 , wherein said biological cells are microorganisms. 
     
     
         11 . The method of  claim 10 , wherein said microorganisms cause said at least one visible dye compound to emit a visible band secondary signal when exposed to visible light. 
     
     
         12 . The method of  claim 1 , wherein said at least one light emitting diode and said at least one light detector face each other. 
     
     
         13 . The method of  claim 1 , wherein said at least one light emitting diode and said at least one light detector are arranged at an angle. 
     
     
         14 . The method of  claim 13 , wherein said at least one light detector detects no direct light generated by said at least one light emitting diode. 
     
     
         15 . The method of  claim 1 , wherein no band-pass filter is employed. 
     
     
         16 . The method of  claim 1 , wherein a multiplicity of fluorescing compounds are excited by a multiplicity of light emitting diodes. 
     
     
         17 . The method of  claim 16 , wherein a multiplicity of containers are employed. 
     
     
         18 . A method for the detection of visible-band fluorescence signals generated by at least one fluorescing compound excited by ultraviolet energy, comprising:
 exciting said at least one fluorescing compound with ultraviolet energy; and   detecting a visible-band fluorescence signal generated by said at least one excited fluorescing compound with a light detector sensitive to electromagnetic energy comprising wavelengths greater than or equal to 400 nanometers.   
     
     
         19 . A device for detecting visible-band fluorescence signals generated by at least one fluorescing compound excited by ultraviolet energy, comprising:
 at least one ultraviolet light-emitting diode generating electromagnetic radiation comprising wavelengths below 400 nanometers and capable of exciting said at least one fluorescing compound; and   at least one light detector sensitive to electromagnetic energy comprising wavelengths greater than or equal to 400 nanometers for the detection of visible-band fluorescence signals generated by said at least one fluorescing compound.   
     
     
         20 . The device of  claim 19 , wherein said light detector is a photo-transistor with diminished sensitivity below 400 nanometers wavelength. 
     
     
         21 . The device of  claim 19 , wherein said light-emitting diode generates a stationary level of energy. 
     
     
         22 . The device of  claim 19 , wherein said light-emitting diode generates pulsated energy. 
     
     
         23 . The device of  claim 19 , wherein said at least one fluorescing compound is chosen from umbelliferons and coumarins. 
     
     
         24 . The device of  claim 19 , wherein said fluorescing compound is dissolved in liquid. 
     
     
         25 . The device of  claim 19 , wherein said fluorescing compound is dissolved in agar. 
     
     
         26 . The device of  claim 19 , wherein said fluorescing compound is impregnated in a matrix. 
     
     
         27 . The device of  claim 24 , wherein biological cells are capable of being grown in said liquid. 
     
     
         28 . The device of  claim 27 , wherein said biological cells are microorganisms. 
     
     
         29 . The device of  claim 28 , wherein said microorganisms cause at least one visible dye compound to emit a visible band secondary signal when exposed to visible light. 
     
     
         30 . The device of  claim 19 , wherein said at least one light emitting diode and said at least one light detector face each other. 
     
     
         31 . The device of  claim 19 , wherein said at least one light emitting diode and said at least one light detector are arranged at an angle. 
     
     
         32 . The device of  claim 31 , wherein said at least one light detector detects no direct light generated by said at least one light emitting diode. 
     
     
         33 . The device of  claim 19 , wherein a multiplicity of fluorescing compounds are excited by a multiplicity of light emitting diodes. 
     
     
         34 . The device of  claim 33 , wherein a multiplicity of containers are employed. 
     
     
         35 . The device of  claim 19 , wherein no band-pass filter is employed. 
     
     
         36 . The device of  claim 19 , further comprising at least one band-pass filter located in the path of said electromagnetic radiation in front of a light sensitive area of said at least one light detector. 
     
     
         37 . An instrument for simultaneous measurements of a multiplicity of fluorescing compounds comprising multiple units each comprising the device according to  claim 19 . 
     
     
         38 . A device for detecting visible-band fluorescence signals and visible-band secondary signals generated by at least one fluorescing compound excited by ultraviolet and visible-band energy, comprising:
 at least one ultraviolet light-emitting diode generating electromagnetic radiation comprising wavelengths below 400 nanometers, said at least one ultraviolet light-emitting diode capable of exciting said at least one fluorescing compound, thereby generating said visible-band fluorescence signal;   at least one visible-band light-emitting diode generating electromagnetic radiation comprising wavelengths greater than or equal to 400 nanometers, said at least one visible-band light-emitting diode capable of interacting with at least one visible dye compound, thereby generating said visible-band secondary signal; and   at least one light detector sensitive to electromagnetic energy comprising wavelengths greater than or equal to 400 nanometers for detecting said visible-band fluorescence signal and said visible-band secondary signal.   
     
     
         39 . The device of  claim 38 , wherein one of said light-emitting diodes is generating stationary'energy and another light-emitting diode is pulsated. 
     
     
         40 . The device of  claim 38 , wherein one light-emitting diode is activated while another light-emitting diode is deactivated, followed by activating said deactivated light-emitting diode and deactivating said activated light-emitting diode, thereby alternately generating said fluorescence signal and said secondary signal. 
     
     
         41 . The device of  claim 38 , wherein said at least one ultraviolet light-emitting diode and said at least one visible-band light-emitting diodes are packaged in a single enclosure. 
     
     
         42 . The device of  claim 38 , wherein the interaction of said visible-band light-emitting diode with said at least one visible dye compound defines the optical transmittance of said at least one visible dye compound.