Real-time Study of Interaction between Adenosine Triphosphateand Its Aptamer Using Dual Polarization Interferometry / 分析化学

ABSTRACT

In this work, we used dual-polarization interferometry to explore the binding events between adenosine triphosphate (ATP) and ATP-binding aptamer (ABA) at solid-liquid interface.The single-stranded ABA was immobilized onto the chip surface.After the addition of ATP, the real-time and label-free technique for detailed investigation of their interactions were reflected on the changes of the mass, thickness, and density through DPI.By analysis of the binding curves from changes in mass, the association rate constant (ka, 4.66×10.3 L/(mol·s), dissociation rate constant (kd, 1.70 × 10.-2 s.-1), dissociation constant (KA, 2.7 × 10.5 L/mol), and association constant (KD, 3.7 × 10.-6 mol/L) were precisely determined.Moreover, good linear correlations between ATP concentrations and three parameters (mass, thickness, density) resolved by the response to ATP binding were obtained.The detection limits (LOD, 3σ) were 0.22 μmol/L for mass calibration, 0.14 μmol/L for thickness calibration, and 0.32 μmol/L for density calibration.We expect that this DPI-based aptasensor can be utilized to study the interactions of functional ABA with ATP, and also can be used for the detection of ATP with high sensitivity.