PublicationsTargeted Ultraviolet Chemical Sensor
Targeted Ultraviolet Chemical Sensors (TUCS) are in-situ, non-contact, non-invasive, non-destructive sensors that require no sample handling or preparation. They employ UV laser induced native fluorescence and resonance Raman spectroscopy to detect and classify unknown molecules and molecular structures. By employing deep UV excitation wavelengths the need for tagging target materials with dyes is eliminated. Dye tags are a significant source of error in many measurements and can obscure the chemistry being measured. Using excitation wavelengths below 250nm, native or endogenous fluorescence and UV Raman emission of target molecules can be measured simultaneously without mutual interference.
Sensitivity and Specificity
Fluorescence Limit of Detection of this sensor is as low as one microorganism at a working distance of 45cm or 100 TRP molecules at a distance of 4cm. Other organic molecules such as BTEX have sensitivity in the PPT range. Resonance Raman sensitivity is about 1000 times lower. Specificity will be discussed later.
Applications
TUCS are designed to be employed as sensitive, in situ, autonomous, industrial or environmental monitors. The sensors developed by Photon Systems operate in the deep ultraviolet to enhance their sensitivity and specificity in identifying certain molecular structures such as organic molecules and well as other molecules that are optimally excited in the UV to emit fluorescence and Raman.
Typical applications for TUCS instruments include in situ, real time measurement and characterization:
- Homeland security detectors for biological and chemical weapons materials;
- Ultrasensitive organic surface contamination detection in high quality optical fabrication, operating room surface inspection, etc.
- Cleaning validation for ultra-sensitive reagent applications
- Water quality in waste treatment plants where the content of nitrates, nitrites, carbonates, aluminates, and other water quality contaminants need to be measured on a regular basis;
- Well water or ocean water quality:sea farming, well water testing, domestic water quality;
- Chemical and microbial detection and identification in water, air and or surfaces
- Quality measurement of synthetic chemical vapor deposited diamond and diamond like carbon films in hard disc drive, super abrasives manufacturing, and other synthetic diamond applications;
- Quality measurement of epitaxial films employed in microelectronics manufacturing; substrate surface quality.
- Quality measurement of the surface condition, chemistry and quality of other elements of microelectronic devices;
- General measurement of targeted chemical compositions in quality control measurements in manufacturing such as adhesives, plastics, organic chemicals, etc
Features
Self-contained deep UV Chemical Sensor containing:
- High power deep UV laser with power supply and digital controller capable of data sampling rates to 30 Hz.
- Spectral isolation filter for excitation wavelength
- Laser excitation power reference detector
- 6 high gain miniature PMT detection channels used to simultaneously detect a combination of laser induced native fluorescence and Raman emissions.
- A choice of number of fluorescence detection channels with selectable band center, bandwidth and slope matched to the chemical environment of the sensor.
- 7 channel PMT controller with digital gated boxcar integrator and averager containing 64MIP microprocessor with 256K RAM and 256K flash memory.
- Power: 5W standby, 6W full power – can be operated by battery or solar cell array.
- Voltage: 24VDC from battery or line source
- Size: 6” x 4” x 14”
- Weight: 5 lbs
- Control: Ethernet, IEEE485, or RF
- Software: Labview VI operated from PDA or other computer
Fluorescence Limit of Detection (FLOD) for tyrptophane molecules and whole microorganisms versus Working Distance