Explosives Detection by Array of Si µ -Cantilevers Coated with Titanosilicate-Type Nanoporous Materials

An array comprising four Si µ -cantilevers coated with nanoporous functionalized ETS-10 crystals sub-micrometric in size has been developed as a multisensing platform for explosives recognition in vapor phase. The detection capabilities of the proposed device have been tested for common taggants such as 1-methyl-2-nitro-benzene (o-MNT)] and explosives (commercial detonation cord, a plastic tube filled with pentaerythritol tetranitrate (PETN); and C-4, a mixture of cyclotrimethylenetrinitramine (RDX), binders and plastifiers). The general strategy for the detection of explosives in vapor phase is based on the characteristic fingerprint each one produces as a result of the dissimilar chemical interactions between the ETS-10 coated µ -cantilevers and the target molecules emanating from the explosives and swept by ambient air. A portable lock-in amplifier has been implemented to exploit the truly benefits of the array in terms of portability, reduced size, and energy consumption. Such low-power electronic interface is capable of creating the excitation signal as well as obtaining the response values of four resonating µ -cantilevers simultaneously. The resulting sensing platform has successfully been applied for the o-MNT, PETN, and RDX detection at trace level.