Determination of Vaporous Aliphatic Amines by Colorimetric Responses of a Molecular Receptor Based on Azobenzothiazole-Polyene Dye

A simple colorimetric method for the determination of vaporous aliphatic amines has been developed. Importantly, the recognition of vaporous aliphatic amines could be observed by naked eyes owing to color change of the synthesized azobenzothiazole-polyene dye from orange to dark blue in the solution. The results revealed that primary amines can form 1:2 and secondary amines 1:1 complexes with the dye, respectively. The sensing of this chemosensor is capable over a dynamic linear ranges between 10
^-2
-10
^-6
M for primary aliphatic amines and 10
^-2
-10
^-4
M for secondary aliphatic amines. The response of the dye to tertiary amines or aromatic amines was not strong enough to make a strong color change. Validation of the assay method revealed excellent performance characteristics, including high repeatability and highly recognizable color change.