MOF-derived porous Co3O4 coupled with AuNPs and nucleic acids as electrocatalysis signal probe for sensitive electrochemical aptasensing of adenosine triphosphate

Abstract

Adenosine triphosphate (ATP), as the primary energy source and significant biomarker, is associated with the occurrence and progression of various diseases. Therefore, detecting ATP sensitively is essential for ATP-related biochemical study, disease diagnosis and treatment. Herein, sensitive electrochemical aptasensing of ATP was proposed based on MOF-derived porous Co3O4 coupled with AuNPs and nucleic acids as a novel electrocatalysis signal probe. Firstly, Au@Co3O4 nanocomposite was synthesized via pyrolysis Co-zeolitic imidazolate framework and then functionalized with AuNPs by in situ chemical reduction, which showed excellent electrocatalytic activity towards hydroquinone (HQ) as well as excellent stability. Then, DNA capture probe (CP) was connected to Au@Co3O4 nanocomposite via Au-S bond to form Au@Co3O4-CP signal probe for signal transduction. Meanwhile, well-designed aptamer probe (AP) containing ATP aptamer and its complementary sequence was immobilized on AuNPs modified electrode surface via Au-S bond. In the presence of ATP, the aptamer in AP interacted with ATP, resulting in the dissociation of AP. Consequently, Au@Co3O4-CP signal probe could be captured on electrode surface via hybridization, leading to a significant amplified electrocatalytic signal towards HQ. Finally, the quantitative determination of ATP was achieved by determining the current signal generated on electrode surface. The proposed electrochemical aptasensor demonstrated excellent sensitivity and selectivity that could detect ATP as low as 0.3 nM. Moreover, the aptasensor showed excellent performance for detecting ATP in complex serum matrix. These results indicate that MOF-derived nanocomposites have promising application in construction of novel electrocatalysis signal probe as well as versatile bioassays.