Fluorescence detection of amantadine based on competitive β-Cyclodextrin host-guest inclusion process

Abstract

Cyclodextrin-based fluorescent probes are promising candidates for chemical or biological sensing due to their wonderful sensitivity and selectivity. Typically, their recognition towards special analysts ascribed from hydrophobic cavity of cyclodextrins. In this work, a cyclodextrin-based fluorescent probe (DASP-β-CD) was synthesized by covalently linking trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium (DASP) and β-cyclodextrin (β-CD). In aqueous dispersion, the DASP-β-CD molecules could form intermolecular inclusion complex which would then generate supramolecular aggregates when increasing DASP-β-CD concentration. However, after adding amantadine (AMD) to DASP-β-CD supramolecular system, AMD molecules would compete with DASP for the cavity site, leading to the destroy of DASP-β-CD intermolecular inclusion complex and disassembly of supramolecular aggregates. Moreover, this AMD-induced collapse of DASP-β-CD intermolecular inclusion complex would also result in the decrease of fluorescence intensity of DASP-β-CD. Based on this, a simple fluorescent assay for the detection of AMD was proposed. This approach provides a rapid, sensitive and selective method for AMD detection and may help designing other cyclodextrin-based sensing strategies for medical analysis and environmental monitoring.