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

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 hy-drophobic cavity of cyclodextrins. In this work, a cyclodextrin-based fluorescent probe (DASP-B-CD) was syn-thesized by covalently linking trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium (DASP) and B-cyclodextrin (B -CD). In aqueous dispersion, the DASP-B-CD molecules could form intermolecular inclusion complex which would then generate supramolecular aggregates when increasing DASP-B-CD concentration. However, after adding amantadine (AMD) to DASP-B-CD supramolecular system, AMD molecules would compete with DASP for the cavity site, leading to the destroy of DASP-B-CD intermolecular inclusion complex and disassembly of supramolecular aggregates. Moreover, this AMD-induced collapse of DASP-beta-CD intermolecular inclusion com-plex would also result in the decrease of fluorescence intensity of DASP-beta-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.