Coil-shaped plastic optical fiber sensor heads for fluorescence quenching based TNT sensing

摘要

Coiled shaped plastic optical fiber (POF) was employed as sensor head to detect nitro aromatic explosives such as TNT. Selectivity for TNT was accomplished by using fluorescence indictor MEH-PPV. The sensor heads were fabricated by twisted around rods with different diameters. Both fluorescence intensity and lifetime were measured to determine the concentrations of TNT. Response varied greatly as a function of diameter of the coil, as the radius of the coil shaped sensor head decreases the sensitivity of the sensor increases. Sensitivity and selectivity of the sensing system were studied. It was also found that the conjugated polymer changes color from red to brownish black when the sensor head was put into TNT solution which was an attractive feature that detection of explosives can be made simply from color images due to rapid color change of an object containing the traces of TNT in daylight and ambient conditions.