Methylamine gas sensing by optical array

Methylamine (MA) represents a threat to human health due to its toxic effects and potential improper use in illicit activities, requiring a sensitive and selective method for its detection. In this work, MA sensing in gas phase has been performed using an optical array, consisting of several organic fluorescent probes, combined with an optical fiber as detector. Precise control of gas concentration has been provided using a gas permeator, which provides a highly stable and reproducible stream of MA. The combination of this system and our optical array leads, compared with other optical sensors, to the lowest linear detection range of 100–1000 ppb, and also, an excellent performance in normal atmospheric conditions. Moreover, the array method exhibits an excellent selectivity in the presence of humidity and other structurally similar molecules.