Artificial-signaling receptors for biologically important chemical species

In this article, I describe the performance of artificial-signaling receptors that have been synthesized. The receptors were designed to enable molecular recognition information to be signaled as changes in the optical properties of the receptors. The contents are divided into two parts. The first deals with spiropyran derivatives as artificial-signaling receptors. This new type of artificial receptor is conceptually different from the signaling receptors so far synthesized such as the crown ether dyes and functionally referred to as self-indicating receptors. The second part is concerned with artificial-signaling acetylcholine receptors, in which the presence of acetylcholine induces a large fluorescence enhancement of the receptors in protic media. The artificial acetylcholine receptors may be applied to histochemistry for acetylcholine.