Binding biomolecules with designed, hydrogen-bonding receptors

An approach to the design of artificial receptors is described involving the fusion of several six-membered rings, preorganizing nitrogen and oxygen hydrogen bonding sites. A hexagonal lattice chemosensor extracts the blood metabolite creatinine into water and acts as a chromogenic reagent for this clinical analyte. Another receptor binds urea via six hydrogen bonds, forming a complex that is stable even in DMSO. A water-soluble receptor has now been synthesized that recognizes the guanidinium sidechain of arginine in aqueous media.