Ammonia selective bulk acoustic wave sensor based on neutral ionophores

A large variety of new coated bulk acoustic wave (BAW) sensors for the detection of ammonia was realized by incorporating a cation-selective neutral ionophore, a H+-selective neutral ionophore and a lipophilic anionic site in the same coating. Such coating generally combines the advantages of a highly selective and reversible recognition of the given ionic substrates. The proposed sensor has a response time of 30 s with linear response over the ammonia concentration range 0.5–20 μg 1−1 (ppm).