Ingenious fabrication of metal–organic framework/graphene oxide composites as aptasensors with superior electrochemical recognition capability

Abstract

The expansion and fabrication of available metal–organic framework (MOF)/graphene oxide (GO) composites is of great importance because of their expectedly splendid properties and extensive applications. In this work, MOF/GO composites are ingeniously fabricated via monolayer dispersed UiO-66-NH₂ on the surface of GO. The obtained composites possess various merits from UiO-66-NH₂ and GO to immensely enhance the electrochemical recognition capability, which is mainly ascribed to the strong affinity between the phosphate terminal of the aptamer and the Zr₆ cluster of UiO-66-NH₂, and to the presence of π–π stacking force between the heterocyclic ring of the aptamer and GO. With adenosine triphosphate (ATP) as analyte, the fabricated UiO-66-NH₂/GO-based aptasensor has the limit of detection (LOD) of 1.69 fg mL⁻¹ (3.33 fM) in a wide concentration range of 1.0 × 10⁻⁵–5.0 ng mL⁻¹, via electrochemical impedance spectroscopy. In terms of preferable stability, operability and repeatability, this biosensor reveals a potentially practical use value for monitoring ATP in real samples. Thus, this work exhibits an effective synthetic strategy to fabricate MOF/GO hybrid composites and further expands their electrochemical sensing applications.