Nanohexagonal Fe2O3 Electrode for One-Step Selective Monitoring of Dopamine and Uric Acid in Biological Samples

Fabrication of nonenzymatic biosensors based on the nanomaterials for highly sensitive and selective detection of single or multiple molecules coexisting in one biological sample is extremely challenging. Design of the hierarchical nanohexagonal Fe2O3 platelets (HFP) via one-pot hydrothermal treatment was employed for selective signaling of dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) with high sensitivity. Electrode design with the nanosized structure of parallel hexagonal platelets (20-40 nm), high surface area, multiactive site, smooth surface, and pore distribution inside/outside the surfaces renders excellent sensitivity and selectivity of DA and UA during the catalytic oxidation process. Simultaneous monitoring and selective signaling of DA and UA were successfully achieved by HFP with detection limits as low as 16 nM and 0.218 mu M with a wide linear range from 1 to 200 mu M and from 20 to 400 mu M for DA and UA, respectively. HFP provides high stability and reproducibility with relative standard deviations in the range of 2.5-5.29% to monitor DA and UA. Furthermore, continuous monitoring of DA and UA in real human saliva/serum samples was realized with high sensitivity and selectivity. The designed HFP can be employed as a nonenzymatic biosensor for simultaneous detection of mono-bioactive molecules in the biological samples.