Anion Detection by a Fluorescent Poly(squaramide): Self-Assembly of Anion-Binding Sites by Polymer Aggregation

摘要

The selective recognition and sensing of anions has been the subject of intensive research effort, motivated by applications in medical diagnostics, environmental and industrial monitoring, and nuclear waste cleanup. Selectivity and affinity may be achieved by preorganization of binding groups in an orientation complementary to the geometry and charge distribution of the anionic guest: sulfate- and phosphate-binding proteins represent impressive illustrations of this principle. While there has been some progress toward synthetic hosts capable of high-affinity, selective anion recognition in competitive (aqueous) environment, the synthesis of preorganized targets having the ideal number and orientation of binding groups for a given analyte is often difficult, and rates of guest binding and release may become problematic. An attractive solution to this problem employs reversible processes (noncovalent or dynamic covalent interactions) as the basis for receptor self-assembly. Self-assembled capsules, dynamic covalent libraries, and coordination complexes capable of anion binding are successful implementations of this concept.