The Preparation And Electrochemical Sensor Performance Of Nanoparticles Based On Iron Series Elements

Iron series elements (Iron, Cobalt and Nickel) have excellent electrochemical catalytic properties. So, a series of iron series elements-based nanoparticles were prepared and modified on glass carbon electrode (GCE) to fabricate electrochemical sensors. Divided into the following three sections:1. The electrochemical sensor based on carbon-supported NiCoO2 nanoparticles (NiCoO2/C) modified glassy carbon electrode (GCE) was constructed to simultaneously determine small biomolecules such as ascorbic acid (AA), uric acid (UA), tryptophan (Trp) and adenine. The morphology and structure of NiCo02 nanoparticles (NPs) were characterized by transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The combination of Ni and Co oxides endowed the NiCoO2/C modified GCE with electrocatalytic activity, sensitivity, and selectivity with well-separated oxidation peaks toward AA, UA, Trp and adenine.2. The NiPd and CoPd nanoparticles were synthsized and modified on GCE to fabricate nitrite ampere sensors. The electrochemical property of detecting nitrite was evaluated by cyclic voltammetry and ampere curve method. Viewing from the results, we can conclude that electrocatalytic activities of the two modified electrodes are far better than commercialized Pd/C electrode, with sensitivity of 5.23 and 5.52 mAmM-1cm-2, respectively. Lastly, these two modified electrodes were also successfully used to detecting nitrites in many curing foods and moat water.3. A Fe3O4-graphene oxide hybrid composite (FesO4-GO) was prepared and used to construct a novel electrochemical sensor for the simultaneous detection of adenine and guanine. The prepared Fe3O4-GO composite was characterized by TEM and XRD. The Fe3O4-GO based electrochemical sensor exhibited linear ranges of 0.05-25 μM and 0.05-25 μM with detection limits of 4 nM and 3 nM for adenine and guanine, respectively. At the same time, this method was applied for the determination of guanine and adenine in thermally denatured DNA samples with satisfying results. The value of (G+C)/(A+T) in DNA was calculated to be 0.7536. The sensor exhibited some advantages, such as simplicity, rapidity, good reproducibility and long-term stability.