Biosensing and biorecognition with water-soluble macrocyclic hosts

This feature article review discusses our efforts and those of others to use water-soluble macrocyclic receptors in the recognition, sensing and discrimination of a wide-ranging scope of biological targets. By using multiple hosts and fluorescent guests in an arrayed manner, a variety of biomolecules can be selectively detected and discriminated via simple optical methods. Targets include post-translationally modified peptides (with modifications as varied as lysine methylations, serine phosphorylation and peptide epimers), enzyme activity (including methyltransferases, demethylases, kinase and phosphatases), as well as anions that vary in size from iodide to non-canonically folded DNA structures. Using pattern recognition techniques allows excellent selectivity, but the key to broad-ranging target scope is to employ multiple orthogonal recognition mechanisms. By varying the recognition mechanism, large target scope and strong selectivity are not inversely correlated: simple host:guest complexes can be a powerful, tunable sensing platform that can be applied to detect multiple different biorelevant species.