Label-free fluorescence aptasensor based on AuNPs and CQDs for the detection of ATP

Abstract

A label-free fluorescence aptasensor was studied for adenosine triphosphate (ATP) detection that combines low biosensor toxicity with a simplified preparation process. In this study, the aptamer of the gold nanoparticle@aptamer@carbon quantum dot nanostructure could specifically identify ATP, resulting in the change of the fluorescence signal. In order to analyze the performance of the sensor, the effects of the carbon quantum dot (CQD) concentration and centrifugal rate on the stability of the probe were investigated. The results show that the sensor was superior under the 220 µl CQD volume and 2000 rpm centrifugal rate. Furthermore, the linear relationship between the change of the fluorescence signal and ATP concentration is Y = 359.747 + 0.226X within the volume range of 20 µM–280 µM. The correlation coefficient is 0.98, and the detection limit is 20 µM. No obvious fluorescence change was observed in solutions containing other common ions. On the basis of no pollution and simplicity, this sensor demonstrates great potential as a low-cost diagnostic tool for the detection of various targets, particularly for use in the fields of food safety and biomedical diagnostics.