An ATP Aptasensor Based on the Peroxidase-like Activity of Hemin/Graphene Oxide Nanosheets

In the present work, a sensitive electrochemical aptasensor was designed for the detection of adenosine triphosphate (ATP) with hemin/graphene oxide nanosheets (HGNs). Firstly, the ATP aptamer was self-assembled on gold electrode surface, and then HGNs were captured to the modified electrode by π-π stacking. The captured HGNs could catalyze the disproportionation reaction of H 2 O 2 , and produced a detectable electrochemical signal by chronoamperometry. ATP was competitively bound to aptamer which led to the release of HGNs from the electrode surface after adding ATP. The decrease of the electrochemical signal, which was calculated by the difference of amperometric responses before and after incubation of ATP, provided a quantitative signal for ATP detection. A linear correlation was achieved between the difference of the amperometric responses and the logarithmic concentration of ATP ranging from 0.5 to 100 nM with a detection limit of 0.08 nM. Besides, the aptasensor also exhibited good selectivity toward ATP against other analogs.