Explosive trace detection with FBAR-based sensor

This paper describes explosive trace detection through mass sensing with film bulk acoustic resonator (FBAR) coated with antibodies. Mass sensing for a specific explosive is done with the use of antibody made specifically for the targeted explosive. Antibodies were immobilized on the backside of FBAR mass sensors using an antibody immobilization protocol. When the specific explosive is exposed to the sensor, it binds to the antibody on the sensor, causing a shift in the resonant frequency of the FBAR sensor. This sensing technique has been shown to selectively detect vapor traces of TNT (trinitrotoluene, a common explosive) and RDX (cyclotrimethylenetrinitramine which has one of the lowest vapor pressures among various explosives) without any pre-concentrator.