A background correctable fluorescence sensing strategy for adenosine triphosphate evaluation based on aptamer configuration alteration

Ratiometric sensors with background correction are expected to get around the interference from complicated systems. However, there is currently a scarcity of viable carriers for quickly and easily assembling fluorophores with varying fluorescence emission. In this work, we developed a novel aptamer-based ratiometric fluorescence sensor for analysis of adenosine triphosphate (ATP) based on the properties of aptamer that enable conformational transformations upon binding to the target. The carbon dots (CDs) and thioflavin T (ThT) are employed as the reference and detection signal for the ratio-dependent sensor, which are both integrated with the aptamer. The green fluorescence of ThT was initially turn-on after binding with aptamer and then quenched in the presence of ATP, whereas the red fluorescence of CDs remained practically steady. This approach exhibits remarkable selectivity and can detect ATP in the range of 0.5–60 μM with a detection limit of 0.167 μM. Moreover, the method was successfully applied to the determination of ATP in human serum as well as in A549 cells, demonstrating the potential for medical diagnostic applications.