Supramolecular cyclization induced emission enhancement in a pillar[5]arene probe for discrimination of spermine

Early diagnosis and treatment of cancer requires the development of tools that are both sensitive and selective in detecting spermine. In this study, we presented a "supramolecular cyclization-induced emission enhancement" strategy for the sensitive and selective detection of spermine. A new pillar[5]arene probe (P1) demonstrated excellent solution/solid dual-state emission properties, and the addition of certain spermine (Spm) resulted in fluorescence enhancement due to the synergy of multiple weak interactions that restricted the free motion of P1 in the P1⊃Spm complex. This mechanism was further confirmed by time-resolved spectroscopy, DFT calculations, and IGM analysis. With its low limit of detection and high selectivity, P1 is a promising tool for measuring spermine in artificial urine samples.