Label-free chemiluminescent ATP aptasensor based on graphene oxide and an instantaneous derivatization of guanine bases

• A label-free chemiluminescent aptasensor for the detection of ATP has been developed utilizing GO-based instantaneous derivatization.
• Aptamers used in this work do not need any labels.
• ATP can be quantitatively analyzed by the CL intensity from the reaction of phenylglyoxal and guanine bases .
• The aptasensor is simple and cost effective which would hold promise in developing label-free CL aptasensor for other targets.

In this work, a novel label-free chemiluminescent (CL) aptasensor has been developed for rapid and facile detection of adenosine triphosphate (ATP, as model analyte) using graphene oxide (GO) nano-platform. The strategy relies on the preferential binding of GO to single-stranded DNA (ssDNA) over rigid double-stranded DNA (dsDNA) or aptamer-target complexes, and the instantaneous derivative reaction between phenylglyoxal (PGO), a special CL reagent as the signaling molecule, and guanine nucleobases (G) of aptamer strands adsorbed on the surface of GO. In the absence of ATP, the aptamers adsorbed onto the surface of GO leading to a strong background CL signal. Conversely, in the presence of ATP, the aptamers formed the aptamer-ATP complexes which had weak binding ability to GO resulting in a significant CL signal decrease. The CL intensity was adversely related to the ATP concentration in the assay solution. The biosensor's signal decreased linearly with the logarithm of the concentration of ATP from 2 to 80 nmol with a detection limit of 1.4 nmol. The aptasensor also showed high selectivity against cytosine triphosphate (CTP), guanosine triphosphate (GTP), and uridine triphosphate (UTP). The method presented here holds the advantages of being label-free, cost effective, rapid, sensitive and selective, which would shows great promise for clinical application.