A UiO-66-NH2/carbon nanotube nanocomposite for simultaneous sensing of dopamine and acetaminophen.

Carbon nanomaterials are quite promising to be combined with metal-organic frameworks (MOFs) to enhance the sensing ability of both materials. In this work, a MOF nanoparticle of UiO-66-NH2 is integrated with carbon nanotubes (CNTs) (UiO-66-NH2/CNTs) with a facile solvothermal method. The morphology, surface area and properties of this UiO-66-NH2/CNTs nanocomposite was investigated using electron microscopy, XRD, XPS, BET analysis and electrochemical techniques. Catalytic oxidation of dopamine (DA) and acetaminophen (AC) on this nanocomposite was achieved, owing to a 3D hybrid structure or a large electroactive surface area, excellent electrical conductivity, a large number of active sites of this nanocomposite. It was further utilized as a sensing platform to establish an electrochemical sensor for the monitoring of both DA and AC. The enhanced oxidation signals led to the voltametric sensing of DA and AC in a broad linear range from 0.03 to 2.0 μM and low detection limits (S/N = 3) of 15 and 9 nM for DA and AC, respectively. The proposed sensor also possessed good reproducibility, repeatability, long-term stability, selectivity, and satisfactory recovery in serum samples analysis. Therefore, it has the great potential for the accurate quantification of DA and AC in complex matrixes.