An antifouling aptasensor is described for voltammetric determination of adenosine triphosphate (ATP). A glassy carbon electrode (GCE) was modified with a graphene oxide and poly(3,4-ethylenedioxythiophene) (GO-PEDOT) composite film by electrodeposition. Next, the zwitterionic peptide (EKEKEKE) was attached. It forms an antifouling layer on the modified GCE and serves as the support for subsequent aptamer immobilization. The resulting aptasensor typically is operated at a potential of 0.18 V (vs. SCE) using hexacyanoferrate as the electrochemical probe. It has a linear response in the 0.1 pM to 1.0 μM ATP concentration range, a 0.03 pM detection limit and a sensitivity of 2674.7 μA·μM-1·cm-2. It has outstanding selectivity, satisfactory reproducibility and desired stability. It was used to quantify ATP in ATP-spiked 10% serum solutions. Graphical abstract Schematic presentation of the construction of the aptamer based electrode for voltammetric determination of ATP.
Keywords: Adenosine triphosphate; Antifouling ability; Aptasensor; Clinical analysis; Contact angle; Electrochemical aptasensor; Electrodeposition; GO-PEDOT composite film; Zwitterionic peptide.