Enhanced electrochemical detection of dopamine and uric acid using Au@Ni-MOF and employing 2D structure DFT simulation

The accurate and expeditious detection of minute biomolecules within human body fluids holds paramount significance in the advancement of novel electrode materials. In this research, a novel non-enzyme electrochemical sensor was constructed. It was founded on Au@Ni-MOF (Ni(CH₃CO₂)₂) hybrids, with Ni(II) (nickel acetate) serving as the precursor. Specifically, [Ni₃(BTC)₂]_n (H₃BTC = 1,3,5-trimesic acid) featuring coordinatively unsaturated Ni(II) sites and decorated with gold nanoparticles was synthesized via an in-situ growth methodology. The Au@Ni-MOF hybrids exhibit outstanding electrochemical and electrocatalytic characteristics, attributable to the meticulous assembly of AuNPs and Ni-MOF. The Au@Ni-MOF (Ni(CH₃CO₂)₂)/SPCE was fabricated onto the surface of the screen-printed electrode (SPCE). Subsequently, its electrochemical performance was probed for the discrete and concurrent quantification of dopamine (DA) and uric acid (UA) in 0.01 M phosphate-buffered saline through differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Notably, the cathodic peak current manifested a linear correlation with the DA and UA concentrations across an extensive range, spanning from 0.1 µM to 2 mM for DA and from 0.5 µM to 1.5 mM for UA, respectively. This sensor is applicable in non-enzyme sensing of DA and UA. Additionally, the adsorption energy and bond length of the 2D structures of Ni-MOF and Au@Ni-MOF (Ni(CH₃CO₂)₂) were ascertained via DFT simulations, thereby affording valuable insights into the interaction mechanisms between biomolecules and the surfaces of these 2D structures.