Functionalized π Stacks of Hexabenzoperylenes as a Platform for Chemical and Biological Sensing

Summary One challenge in tailoring organic semiconductors for sensing applications is that the introduction of reactive groups or binding sites usually impairs π-π interactions. To meet this challenge, this study puts forth an unusual type of π stacking that allows a variety of functional groups to be grafted onto organic semiconductors without sacrificing π-π interactions in the solid state. As a result of this type of π stacking, the self-assembly of functionalized hexabenzoperylenes (HBPs) provides a general sensing platform for various chemical and biological species. This supramolecular platform, in a device integrating an organic field-effect transistor channel and a microfluidic channel, has enabled highly sensitive and selective detection of fluoride ions and streptavidin in water when HBPs are equipped with a cleavable Si–O bond and a biotin moiety, respectively.