Electrochemical sensor based on a green-synthesized ZnO/CD-MOF/rGO nanocomposite for simultaneous detection of dopamine and uric acid in the presence of ascorbic acid

Here, an ultra-selectivity electrochemical sensor was created to measure dopamine (DA) and uric acid (UA) simultaneously. A GCE modified with ZnO nanoparticles and β-cyclodextrin metal-organic framework decorated reduced graphene oxide (ZnO/CD-MOF/rGO/GCE) was successfully fabricated. The biosynthesized algal-based ZnO NPs and CD-MOF were characterized by TGA, FT-IR, XRD, SEM, and EDX. The fabricated electrode displayed good electro-catalytic activity towards oxidation of DA and UA in phosphate buffer solution (PBS) at pH 7.0. Under optimal conditions, the method exhibited a linear response to DA and UA concentrations range of 50 nM - 500 μM, with low limits of detection (S/N = 3) of 4.337 nM and 8.198 nM, respectively. Further, the prepared sensor exhibited desirable reproducibility, longtime stability, and high selectivity, and effectively distinguishing both biomolecules from common interferents. The proposed sensor provides a simplified method to determine DA and UA in biological samples with satisfy recoveries. • ZnO nanoparticles were green-synthesized using algal extract and incorporated into a CD-MOF/rGO composite. • The nanomaterials were characterized using TGA, FT-IR, XRD, SEM, and EDX. • The ZnO/CD-MOF/rGO composite enabled simultaneous electrochemical detection of dopamine and uric acid. • The sensor showed wide linear ranges and low detection limits (4.337 nM DA; 8.198 nM UA). • The platform exhibited high stability, sensitivity, and selectivity even in the presence of ascorbic acid.