Sensitive fluorescence detection of ATP based on host-guest recognition between near-infrared β-Cyclodextrin-CuInS₂...

We have developed a near-infrared (NIR) fluorescent aptamer-based sensor for sensitive detection of adenosine-5'-triphosphate (ATP) by using a ATP-binding aptamer and β-Cyclodextrin-CuInS₂ quantum dots (β-CD-CuInS₂ QDs). The fluorescence of β-CD-CuInS₂ QDs has a slight enhancement with the addition of ATP-binding aptamer due to the host-guest recognition between aptamer and β-CD. When ATP is added, it will bind to aptamer to form G-quadruplexes. Aptamer-ATP complexes can enter into the hydrophobic cavities of β-CD and result in great enhancement of the fluorescence intensity. Under the optimum conditions, the fluorescence intensity of β-CD-CuInS₂ QDs is proportional to the concentration of ATP, which shows a good linear response toward ATP concentration range of 6-1200μmolL^-1, the detection limit for ATP is 3μmolL^-1. The present assay shows a good selectivity for ATP over other biologically important proteins, and it is applied to the determination of ATP in human serum sample with satisfactory results.