Simultaneous Electrochemical Detection of Ascorbic Acid, Dopamine and Uric Acid Using the Composite Materials of Fe₃O₄ and Nitrogen Self-Doped Sunflower Plate-Derived Carbon

Abstract

A simple pyrolysis, activation and hydrothermal method was utilized to synthesize composite materials (Fe3O4/SFP) of ferroferric oxide and nitrogen self-doped sunflower plate-derived carbon for the simultaneous electrochemical sensing of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The Fe3O4/SFP had synergistic catalytic effect on target molecules, and the oxidation peak potential of AA, DA and UA was well distinguished in the differential pulse voltammetry determination. Under the optimal conditions, the linear response ranges of AA, DA and UA are 3–150[Formula: see text][Formula: see text]M, 5–450[Formula: see text][Formula: see text]M and 15–1200[Formula: see text][Formula: see text]M, respectively. The detection limits of AA, DA and UA ([Formula: see text]/[Formula: see text]) are 1.0[Formula: see text][Formula: see text]M, 0.4[Formula: see text][Formula: see text]M and 1.48[Formula: see text][Formula: see text]M, respectively, and the sensitivity is 1.87[Formula: see text][Formula: see text] (3–20[Formula: see text][Formula: see text]M) and 0.64[Formula: see text][Formula: see text] (20–150[Formula: see text][Formula: see text]M) for AA, 3.90[Formula: see text][Formula: see text] (5–20[Formula: see text][Formula: see text]M) and 1.21[Formula: see text][Formula: see text] (20–450[Formula: see text][Formula: see text]M) for DA and 1.12[Formula: see text][Formula: see text] (15–100[Formula: see text][Formula: see text]M) and 0.31[Formula: see text][Formula: see text] (100–1200[Formula: see text][Formula: see text]M) for UA. In addition, satisfactory results have been obtained for the determination of AA, DA and UA in normal human serum, which provides a new research direction for the construction of electrochemical sensors in the future.

Fe3O4-Nanoparticle-Modified Sensor for the Detection of Dopamine, Uric Acid and Ascorbic Acid

“…To study this effect, the pH of the solution was adjusted from 6 to 9; lower pHs favor partial dissolution of magnetite in the medium [25]. Figure 8 shows that there is not a great variation in the detection signal with pH, but it can be observed that the current gradually decreases with increasing or decreasing pH; similar results have been obtained using Fe 3 O 4 and nitrogen self-doped sunflower plate-derived carbon as an electrochemical sensor [26]. The best pH seems to be approximately 7.5 for uric and ascorbic acid and 7 for DA.…”