Electrostatically enhanced host-guest complexation: a fluorescence platform for highly sensitive detection of heparin

A highly sensitive fluorescent system for heparin detection was developed using a mixture of a cationic fluorescent dye (4-(4-diethylaminostyryl)-1-methylpyridinium iodide, SMP) and a cationic modified cyclodextrin (β-CD-C₆). The electrostatic binding between SMP, β-CD-C₆ and heparin, respectively, enhanced the host-guest complexation between SMP and β-CD-C₆, and consequently the fluorescence emission of SMP. The fluorescence enhancement of the SMP/β-CD-C₆ system was sensitive to the level of heparin with high selectivity. Furthermore, an assay platform based on the fluorescence enhancement of SMP/β-CD-C₆ in 10 % serum was successfully established. In addition, the SMP/β-CD-C₆/heparin complex showed a potential sensing capability of protamine due to the higher affinity between protamine and heparin. This platform showed great promise for heparin sensing applications.