Microsensors for In-Situ, Real-Time Detection and Characterization of Toxic Organic Substances
We have further developed and demonstrated the novel ORNL micro-calorimetric spectroscopy technique for the detections and characterization of toxic organic substances. In this technique target molecules were allowed to adsorb on the surface of sub-femtojoule sensitive micromechanical thermal detectors. The adsorption of molecules on the thermal detector surface causes a differential surface stress resulting in an initial ''trigger''. By exposing the thermal detector microstructure elements to different photon wavelengths, an extremely sensitive and unique photothermal signature response was obtained. We adsorbed sub-monolayer levels of target chemicals onto the bi-material detector surfaces. We obtained infrared photothermal spectra for trace concentrations of several organics such as diisopropyl methylphosphonate (DIMP), and trinitrotoluene (TNT) over the wavelength region 2.5 to 14.5 {micro}m. We found that in the wavelength region 2.5 to 14.5 {micro}m the photothermal spectra of DIMP and TNT exhibit a number of peaks and are in excellent agreement with traditional infrared absorption spectra found in the literature. Chemical detectors based on micro-calorimetric spectroscopy can be used to sensitively sense a relatively small number of molecules adsorbed on a thermal detector surface. This photothermal signature resulting from photon irradiation and subsequent thermal transfer can be used for improved chemical characterization.
- Research Organization:
- Oak Ridge National Laboratory (US)
- Sponsoring Organization:
- INDUSTRY FUNDS-IN CRADA (US)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 786753
- Report Number(s):
- ORNL/TM-2001/82; TRN: AH200133%%137
- Resource Relation:
- Other Information: PBD: 14 May 2001
- Country of Publication:
- United States
- Language:
- English
Similar Records
Infrared microcalorimetric spectroscopy using uncooled thermal detectors
Detection and Characterization of Chemicals Present in Tank Waste