Detection of Explosives Using Amplified Fluorescent Polymers

Publisher Summary This chapter focuses on the use of amplified fluorescent polymers in the detection of explosives. Chemical sensing using fluorescent quenching (FQ) of amplified fluorescent conjugated polymers is a powerful technique that can achieve high sensitivity for vapor-phase analytes. Electron-transfer-induced FQ is the most practical and efficient mechanism of signal transduction for the detection of explosives, such as 2,4,6-trinitrotoluene (TNT), as they are often highly electron-deficient molecules that readily accept electrons from excited fluorophores. Explosive devices that contain TNT also usually contain a synthetic by-product called 2,4-dinitrotoluene (DNT), which is also highly electron deficient. Several different types of operable devices have been successfully fabricated by ICx Technologies under the name Fido, which allows the use of a small amount of associated optics and electronics. As a result, complete, portable hand-held devices weighing less than 2 lb have been developed and successfully tested for personnel, vehicle, and container screening. The ability of this technology to support small, lightweight, and portable devices has in part led it to be especially successful in the detection of land mines, where the principal explosive component is TNT. These sensor devices respond only to nitroaromatics and similarly small, electron-deficient analytes, which are found typically only in or close to explosives and explosive devices. As a result, this technology has been successfully field tested in many different scenarios, from the screening of vehicles to the detection of land mines and even underwater explosive detection. The effectiveness and applicability of these materials and devices are constantly being improved by research in both industry and academia.