Native fluorescence detection methods, devices, and systems for organic compounds

Inventors

Hug, William F. • Bhartia, Röhit • Reid, Ray D. • Lane, Arthur L.

Assignees

Photon Systems Inc

Abstract

Naphthalene, benzene, toluene, xylene, and other volatile organic compounds VOCs have been identified as serious health hazards. Embodiments of the invention are directed to methods and apparatus for near-real-time in-situ detection and accumulated dose measurement of exposure to naphthalene vapor and other hazardous gaseous VOCs. The methods and apparatus employ excitation of fluorophors native or endogenous to compounds of interest using light sources emitting in the ultraviolet below 300 nm and measurement of native fluorescence emissions in distinct wavebands above the excitation wavelength. The apparatus of some embodiments are cell-phone-sized sensor/dosimeter “badges” to be worn by personnel potentially exposed to hazardous VOCs. The badge sensor of some embodiments provides both real time detection and data logging of exposure to naphthalene or other VOCs of interest from which both instantaneous and accumulated dose can be determined.

Core Innovation

The invention provides a VOC sensing method in which a sample location within a housing has a temperature controllably varied from less than ambient temperature to at least ambient temperature. Excitation radiation with a wavelength of less than 300 nm is provided at least one time while the sample location is controlled to be less than ambient temperature, and the excitation radiation is generated by a source within the housing and directed onto the sample location to induce native fluorescence emission radiation originating from the sample location.

The native fluorescence emission radiation is received and directed along at least one detection path within the housing by at least one optical element. The fluorescence is detected at least once at at least one location along the detection path by at least one detector within the housing, and the detected native fluorescence emission radiation is used to determine whether the detected native fluorescence corresponds to a volatile organic compound of interest, or to determine a concentration of a VOC of interest.

The claimed approach integrates temperature control of the sample location, deep UV excitation below 300 nm, optical routing along detection paths, and native fluorescence detection within a housing. The method uses fluorescence signals associated with VOCs for identification and/or concentration determination.

Claims Coverage

The provided material includes two independent claims. Both independent claims share the same core sensing architecture, with the final determination differing between correspondence/identification and concentration determination. Across the claims, the inventive features are the temperature-varied sample location in a housing, deep UV excitation below 300 nm during below-ambient operation, and native fluorescence emission routed through optical elements to detectors along detection paths for VOC determination.

Both independent claims are directed to a VOC sensing method that combines controllably varied sample-location temperature in a housing, excitation radiation of wavelength less than 300 nm applied while the sample location is below ambient, optical elements directing native fluorescence along detection paths, and at-least-once detection by at-least-one detector. The distinction is that one claim uses the detected fluorescence to determine correspondence to a VOC of interest, while the other uses it to determine a concentration of a VOC of interest.

Stated Advantages

Documented Applications