Abstract: Embodiments of the present disclosure describe a colorimetric sensor comprising a substrate including an activated furan and configured to undergo a color change upon detecting an amine. Embodiments of the present disclosure describe a method of using a colorimetric sensor comprising applying an activated furan to a substrate, providing the substrate to a medium, and detecting an amine in the medium via change in color of the substrate. Embodiments of the present disclosure further describe a method of detecting an amine comprising contacting furfural with a cyclic acceptor group to form an activated furan for detecting amines, and contacting the activated furan with an amine to produce a colored donor-acceptor Stenhouse adduct.