Lanthanide-Containing Cyclophanes for the Detection of Explosives and Propellants
Abstract
Testing ranges are subject to increased exposure from propellants and explosives as these chemicals leach from ordinance shells. Consequently, the neighboring ground water is at risk of contamination from these pollutants. In order to identify areas that require clean up or are at risk of high levels of these contaminants, a chemical assay is first needed to provide a rapid test for the specific analytes of concern. A chemical assay can then be adapted to other forms of deployment such as dipstick or spray-on techniques for screening localized or large areas, respectively. An efficient assay provides a rapid diagnosis of the sampled soil or ground water with a minimum chance of false positives. In order to transduce the presence of a propellant or explosive into a readable output, a receptor must selectively interact with the particular chemical of interest. Subsequently, the binding event triggers a spectroscopic or electrical response within the receptor, which provides the output signal indicating positive identification. The selectivity of the receptor for the specific propellants and explosive determines the rate of false positives in the chemical assay. However, this selectivity must be balanced with high sensitivity to avoid false negatives. For example, a highly selective receptor may require high concentrations of TNT in order to indicate a positive response to the explosive and low levels of TNT may be undetectable. Similarly, a highly sensitive sensor may indicate a false positive response for innocuous chemicals found in the environment. A functionalized cyclophane receptor was synthesized to selectively bind aromatic explosives such as TNT. The organic cyclophane is functionalized with ligating capabilities along its periphery, which allow for the binding of lanthanide chromophores. The fluorescence properties of lanthanides are significantly altered upon binding of the aromatic analytes into the cavity of the cyclophane.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2006
- Accession Number
- ADA603994
Entities
People
- Nicholas Prokopuk
Organizations
- Naval Air Warfare Center