Photostimulated interactions of bipyridinium-azobenzene with a β-aminocyclodextrin monolayer-functionalized electrode: An optoelectronic assembly for the amperometric transduction of recorded optical signals

An amino-functionalized β-cyclodextrin is covalently linked to a thiopropionic acid-active ester monolayer associated with a Au electrode to yield a cyclodextrin monolayer electrode. The photoisomerizable electron acceptor trans or cis N-methylpyridinium-4-(4′-N′-methylenepyridinium)-azobenzene, 1t or 1c, respectively, exhibit different binding affinities for the β-cyclodextrin-receptor-monolayer. The photoisomer 1t has a high affinity for the cyclodextrin monolayer while 1c exhibits low binding interactions to the monolayer interface. The photostimulated binding and dissociation of 1t or 1c to and from the monolayer are transduced electrochemically. The association and dissociation of the photoisomerizable substrate to and from the monolayer are confirmed by microgravimetric, quartz-crystal-microbalance experiments.