LABEL-FREE FLUORESCENT APTASENSOR BASED ON A GRAPHENE OXIDE SELF-ASSEMBLED PROBE FOR THE DETERMINATION OF ADENOSINE TRIPHOSPHATE

A sensitive and selective fluorescent aptasensor for adenosine triphosphate (ATP) was fabricated, composed of unbound SYBR Green I, graphene oxide, and a label-free detection probe. When ATP and complementary DNA of a signal probe were introduced, p-stacking interactions repelled the probe from the graphene oxide and formed a DNA-SYBR Green I duplex structure, triggering an increase in the fluorescence. ATP was determined over a linear range of 10 to 700 nM with a detection limit of 1 nM. The method displayed good selectivity, and is currently the most sensitive ATP fluorescence method. Furthermore, prominent fluorescence signals were also obtained in cellular assays. Consequently, the biosensor may have significant applications in protein, pathogenic microorganisms, and small molecule detection.