β-Cyclodextrin polymer based fluorescence enhancement method for sensitive adenosine triphosphate detection

Adenosine triphosphate plays a crucial role in regulation of many biological pathways and has been used as an indicator for many diseases. In this paper, based on the fact that β-cyclodextrin polymer (polyβ-CD) could significantly enhance pyrene fluorescence through supramolecular assembly (host-gest interaction), a sensitive and facile method for adenosine triphosphate detection has been developed. A 3'-pyrene-labelled ATP-binding aptamer was employed as the fluorescence probe, which could be digested by exonuclease I to obtain mononucleotides, with pyrene attached on. The pyrene attached on mononucleotides could easily enter the hydrophobic cavity of polyβ-CD, accompanied with prominent fluorescence enhancement. While ATP was introduced, ATP and its aptamer could combine together and the obtained hairpin complex could not be cleaved by exonuclease I. The pyrene labelled on the probe could not enter the cavity of polyβ-CD belong to the complex' steric hindrance, accompanied with the weak pyrene' fluorescence. So we could quantify the concentration of adenosine triphosphate facilely by measuring the fluorescence intensity of the system. The detection limit of this method for adenosine triphosphate was 11 μmol/L (S/N=3). The developed method showed sufficient selectivity and could successfully assay adenosine triphosphate in biological samples. The developed method provides a potential platform for biological micromoles assay.