Assessing the sensing limits of fluorescent dendrimer thin films for the detection of explosive vapors

摘要

Photoluminescence quenching of organic thin films is a promising technique for the detection of vapors from explosives. The photoluminescence quenching response depends on the energetics of electron transfer from the photo-excited sensing material to the analytes, the vapor pressure of the analyte, and the diffusion process of the analytes in the sensing films. It is critical that the performance of a potential sensing material be evaluated in the solid-state with a range of analytes and across a range of vapor concentrations to ensure high sensitivities through non-contact sampling are achievable. We have investigated the photoluminescence quenching of three generations of carbazole-based dendrimers across a range of nitro-containing analyte vapor concentrations, including the TNT by-product 2,4-dinitrotoluene (DNT), and the tagging agent 2,3-dimethyl-2,3-dinitrobutane (DMNB). We show that the performance of all three dendrimer generations in the solid-state is near identical. Furthermore, we show that these dendrimers have a high affinity towards nitroaromatic compounds with parts per billion sensitivity, which makes them ideal for trace-level detection.