Concentration-independent fingerprint library of volatile organic compounds based on gas-surface interactions by self-assembled monolayer functionalized film bulk acoustic resonator arrays

This paper reported a novel e-nose type gas sensor based on film bulk acoustic resonator (FBAR) array in which each sensor is functionalized individually by different organic monolayers. Such hybrid sensors have been successfully demonstrated for VOCs selective detections. Two concentration-independent fingerprints (adsorption energy constant and desorption rate) were obtained from the adsorption isotherms (K
a
, K
1
, K
2
) and kinetic analysis (k
off
) with four different amphiphilic self-assembled monolayers (SAMs) coated on high frequency FBAR transducers (4.44 GHz). The multi-parameter fingerprints regardless of concentration effects compose a recognition library and improve the selectivity of VOCs.