Novel optical sensor for the instantaneous detection and identification of bioaerosols

• US 20080204746A1
• Filed: 11/18/2005
• Published: 08/28/2008
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: Caribbean Biotechnologies, Inc.
• Original Assignee: Caribbean Biotechnologies, Inc.
• Inventors: Gonzalez Cruz, Jorge E., Salazar Izquierdo, Victor M., Vega, Alfredo Ortiz
• Granted Patent: US 7,595,864 B2
• Time in Patent Office: Days
• US Class Current: 356/319
• CPC Class Codes: G01J 3/4406 Fluorescence spectrometry
• CPC Class Codes: G01N 21/6402 Atomic fluorescence; Laser induced fluorescence
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence

Abstract

The invention relates to an apparatus and a process of using the said apparatus in the in-time air sampling, detection and identification of bioaereosols; wherein identification of the said aerosol is based on a multiphoton laser diagnostic technique in combination with the velocity and aerodynamic size of the particular bioaerosol.

Claims

1. An instantaneous laser-induced multiphoton fluorescence sensor of bioaerosols comprising:

a) an air flow system to deliver an aligned stream of particles to and through the optical system;

b) a nozzle coupled to the air flow system and having its end directed to the detection location, wherein through the said nozzle a string of particles are delivered to the said detection location;

c) an optical system that transfer light from the particle to a first focal plane to a second focal plane;

d) a first and second parallel trigger laser emitting a beam of the same wavelength that is focused in the way the string of particles flow so once the particles passed in front of each one of the said beams, scattering of the light takes place;

e) an avalanche photo detector sensitive to the light scattered by the passing of particles in front of the triggered laser beams having the same wavelength;

f) a probe pulse femtosecond laser which emits a pulse of light having a predetermined diameter centered on the particle detection volume triggered by the logically ANDed output signals of the first an second wavelength selective photodetectors to emit a pulse of light substantially in the first focal plane and downstream of the particle detection volume;

g) an spectrophotometer sensitive to the emission of fluorescence of excited particles locate in front of the femtosecond laser at the opposite side of the optical detection cavity;

h) a computerized and electrical system optically connected to the nozzle, the avalanche photodetector and the spectrophotometer wherein the said computerized electrical system integrates all the electronic components of the apparatus that allows the apparatus to function in an autonomous way.

2. The sensor of claim 1 wherein the first and second parallel lasers are diode lasers.

3. The sensor of claim 1, wherein the wavelength of the first and second trigger laser is substantially 650 nm.

4. The sensor of claim 1, wherein the wavelength of the femtosecond laser is in the range of substantially 790 to 810 nm.

5. The sensor of claim 1, wherein the wavelength of the femtosecond laser is substantially 800 nm.

6. The sensor of claim 1, wherein the nozzle has an inlet diameter entrance and a inner diameter entrances.

7. The sensor of claim 6, wherein the nozzle'"'"'s inlet diameter entrance is substantially 20 mm and the inner diameter entrance is substantially 10 mm.

8. The sensor of claim 1, wherein the optical system comprises lens.

9. The sensor of claim 1, wherein the air flow system comprises means control the delivery of particles to the detection location at a one particle at the time rate.

10. The sensor of claim 1, wherein the computerized electrical system collects, calculates, measures, stores and compares data collected with a library of data for bioaerosol identification purposes.

11. A method for obtaining two photon excited fluorescence spectra library of bioaerosols, said method comprising:

a) preparing an aqueous solution of a particular bioaerosol in deionized water having a particular and known concentration;

b) sonicating the said aqueous solution in order to obtain a solution at nanomolar concentration;

c) exposing the sample to a femtosecond laser in order to induced fluorescence emission;

d) collecting the fluorescence spectrum of the emission of the sample;

e) repeating the above steps (a) through (d) with another bioaerosol in order to generate a particular and unique spectrum of the selected bioaerosol;

f) collecting all of the spectra in order to form a spectra library of bioaerosols.

12. The spectra library obtained by the method described in claim 11.

13. An apparatus for the detection and the substantially identification of bioaerosols comprising:

a) an air flow system to deliver an aligned stream of particles to the optical system;

b) an optical system wherein the velocity and the aereodynamic size of the particle is determined and wherein the multiphoton fluorescent emission of the said particle is induced and collected and;

c) an computerized electrical system comprising that integrates all the electronic components of the apparatus and that allows it to works in an autonomous way.

14. A method for the instantaneous laser-induced multiphoton fluorescence detection and identification of bioaereosols comprising:

a) collecting an air sample and delivering an aligned stream of particles to laser beams;

b) passing the particles through the laser beams producing a radiation scattering detected by the high sensitivity avalanche photodiode;

c) exciting the particle with a femtosecond laser producing a multiphoton excitation that induced a unique fluorescent spectrum signal that is recorder by the spectrometer;

d) internal comparison of the said spectrum signal with a bank data already stored in a spectrometer computer in order to identify the bioaerosol particle.

15. The method of claim 14 wherein the bioaerosol is a bacterium harmful to mammals.

16. The method of claim 15 wherein the bioaerosol is a bacterium harmful to humans.