Photochemical Imprint of Molecular Recognition Sites in Two-Dimensional Monolayers Assembled on Au Electrodes:  Effects of the Monolayer Structures on the Binding Affinities and Association Kinetics to the Imprinted Interfaces¹

Photochemical imprint of molecular recognition sites for phenoxynaphthacene quinone (1a) in two-dimensional monolayers assembled on Au surfaces is accomplished. The photochemical imprint of the molecular recognition sites involves several steps:  The primary step includes the assembly of the trans-phenoxynaphthacene quinone monolayer (2a), followed by the rigidification of the monolayer with long-chain alkanethiols that generates a densely packed quinone monolayer. The second process involves the photoisomerization of the monolayer to the ana-quinone state (2b), followed by the nucleophilic displacement of the quinone with butylamine. The association of 1a to the imprinted sites and the dissociation of the host substrate from the sites are followed by electrochemical means as well as by microgravimetric quartz-crystal-microbalance measurements. The binding of 1a to the imprinted recognition sites reveals selectivity, and structurally related substrates do not associate to the imprinted sites. The kinetics...