Mip-Based Low-Cost Sensor for Short-Range Detection of Explosives

Fast, selective, sensitive and inexpensive detection techniques are highly required concerning the identification of planned terrorist attacks in- volving explosive, chemical or biological materials. State of the art are cost intensive equipments used e.g. in airport portal systems or swapping techniques (Imaging by X-ray, TeraHz-, MMwave, NQR, neutron activation techniques, electronic noses, IMS). We propose the development of substance specific low cost sensors, which can be installed as self reporting sensors in containers, compartments, wagons etc., used as hand held systems or sniffing devices which analyse the content of explosives in the gas phase. The basic sensor concept uses mass-sensitive devices coated with mole- cularly imprinted polymers (MIP). The components are cheap promising low- cost detection devices which could be applied for the passive as well as active sensing of explosives like TNT, DNT or TATP at short-range distances of about one meter. In the case of active sampling the MIP sensor will be combined with a suitable air-sucking system. Molecular imprinted polymers (MIPs) are highly cross-linked polymers. Like enzymes they possess a high affinity and selectivity for the adsorption of a special target substance (template molecule) which is present only during the MIP-synthesis and is afterwards extracted. This yields to a finished polymer with special and very selective binding sites for the former template. MIPs are very inexpensive, rapid to synthesise and they are already applied as substance specific solid phase extraction materials in the liquid phase. Preliminary results /1/ of synthesized particulate TNT-specific MIPs showed the effective adsorption capability of the material for TNT vapours. Moreover first experiments using direct UV-initiated polymerisation of TNT- MIPs produced thin films which can be used in combination with different sensor materials.