Aggregation control of hemicyanine fluorescent dye by using of cucurbit[7]uril and pillar[6]arene

Abstract

The aggregation of cyanine-based fluorescent dyes easily results in the fluorescence quenching, which limits the applications in biological science and materials science. So developing an efficient method to adjust the aggregation of cyanine dyes is very significant. In this work, we employ two different macrocyclic hosts pillar[6]arene (DEP[6]) and cucurbit[7]uril (CB[7]) to investigate their effects towards fluorescence spectra of dye 1. The result indicates that both of them can disrupt the aggregation of dye 1, resulting in the enhancement of its fluorescence intensity. Interestingly, investigation on the corresponding titration experiments of 1H NMR and density functional theory calculations shows that CB[7] and DEP[6] play different roles in the process of disaggregation. DEP[6] and CB[7] could be applied to tune the fluorescence of dye 1.