Autogenous-reduction-engineered MOF/GO hybrids as a universal ternary nanocomposite platform for simultaneous electrochemical sensing of uric acid, dopamine and ascorbic acid

Fluctuations in neurotransmitters and essential metabolites are closely linked to the development and progression of multiple diseases. Accurate monitoring of these biomolecules provides critical information for early diagnosis, disease evaluation, and timely clinical intervention. However, their coexisting electrochemical detection remains impeded by signal overlap due to similar redox potentials, such as uric acid (UA), dopamine (DA) and ascorbic acid (AA). This work reports a universal in-situ synthesis strategy to construct Zr-based metal-organic frameworks (MOFs) (UiO-66)/graphene oxide (GO) complexes, wherein the GO dosage critically regulates the crystallinity and pore architecture of UiO-66. Subsequent integration with protonated polyaniline (PANI) yields ternary composites (UiO-66/GO/PANI) as an electrochemical sensing platform for the simultaneous detection of UA, DA, and AA. Significantly, the partial autogenous reduction of GO during solvothermal synthesis eliminates the need for dedicated reduction steps and toxic reductants while enhances conductivity. The UiO-66/GO/PANI-modified glassy carbon electrode exhibits well-separated oxidation peaks for UA (0.32 V), DA (0.19 V), and AA (0.007 V). The sensor achieves low detection limits of 2.12 μM for UA, 1.68 μM for DA, and 18.49 μM for AA, together with excellent selectivity and practical applicability in complex samples. This work establishes a green synthesis paradigm for MOF/GO hybrids and provides a universal biosensing strategy for neurotransmitter and metabolite, with potential extensibility to complex biomarker panels in neurological diagnostics.