A Novel Enzyme-Free Biosensor Based on Porous Core–Shell Metal Organic Frame Nanocomposites Modified Electrode for Highly Sensitive Detection of Uric Acid and Dopamine

A novel enzyme-free biosensor based on porous metal organic frame nanocomposites, i.e., core–shell structured Au@NC@GC nanocomposites, has been constructed for simultaneous determination of uric acid (UA) and dopamine (DA). Au@ZIF-8@ZIF-67 was prepared through a seed-mediated growth method and carbonized in nitrogen atmosphere to synthesize a nanoporous hybrid carbon materials (Au@NC@GC). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies demonstrate that the as-prepared Au@NC@GC modified glassy carbon electrode (Au@NC@GC-GCE) possesses a high selectivity and sensitivity for simultaneous detections of UA and DA. It exhibited wide linear responses for UA and DA in the range from 10 μ M to 600 μ M and 10 μ M to 150 μ M, with the detection limits of 0.773 nM and 0.746 nM, respectively (S/N = 3). Moreover, this novel electrochemical biosensor could be further utilized in biological analysis (i.e., human serum), and the satisfactory recovery results of UA and DA could be readily obtained. These afore-mentioned results further manifest that the as-prepared biosensors are capable for quantitatively monitoring UA and DA in serum, verifying the possibility for its future promising applications in real biological or clinic samples analysis.