Explosives detection by using 8-microcantilever chips with self-heating elements modified with exchanged BEA type zeolites

Si microcantilevers with internal heating elements and modified with selective zeolite coatings have been developed and used for the selective detection of 2-nitrotoluene (o-MNT) in vapor phase as probe molecule of nitroderivates explosives family (TNT, picric acid). In particular, transition metal exchanged BEA zeolites have been deployed as a sensitive layer over microfabricated chips containing 8 Si-cantilevers by microdropping technique. Limit of detection (LOD) values below 1 ppm have been attained at room temperature conditions for Co-BEA coatings. Integrated heater provides an easy and fast regeneration of the zeolite adsorption capability, enhancing sensor reproducibility and sensitivity. The explosives recognition capability of the sensing platform could be notably enhanced by tuning the sensing temperature. The calculated apparent isosteric sorption values for single compounds have been revealed as valuable tool for O-MNT identification in multicomponent mixtures.