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. 2018 Jan 12;18(1):199.
doi: 10.3390/s18010199.

Preparation of Cu₂O-Reduced Graphene Nanocomposite Modified Electrodes towards Ultrasensitive Dopamine Detection

Quanguo He  1 , Jun Liu  2 , Xiaopeng Liu  3 , Guangli Li  4 , Peihong Deng  5 , Jing Liang  6
Affiliations

Preparation of Cu₂O-Reduced Graphene Nanocomposite Modified Electrodes towards Ultrasensitive Dopamine Detection

Quanguo He et al. Sensors (Basel). .

Abstract

Cu₂O-reduced graphene oxide nanocomposite (Cu₂O-RGO) was used to modify glassy carbon electrodes (GCE), and applied for the determination of dopamine (DA). The microstructure of Cu₂O-RGO nanocomposite material was characterized by scanning electron microscope. Then the electrochemical reduction condition for preparing Cu₂O-RGO/GCE and experimental conditions for determining DA were further optimized. The electrochemical behaviors of DA on the bare electrode, RGO- and Cu₂O-RGO-modified electrodes were also investigated using cyclic voltammetry in phosphate-buffered saline solution (PBS, pH 3.5). The results show that the oxidation peaks of ascorbic acid (AA), dopamine (DA), and uric acid (UA) could be well separated and the peak-to-peak separations are 204 mV (AA-DA) and 144 mV (DA-UA), respectively. Moreover, the linear response ranges for the determination of 1 × 10-8 mol/L~1 × 10-6 mol/L and 1 × 10-6 mol/L~8 × 10-5 mol/L with the detection limit 6.0 × 10-9 mol/L (S/N = 3). The proposed Cu₂O-RGO/GCE was further applied to the determination of DA in dopamine hydrochloride injections with satisfactory results.

Keywords: Cu2O nanoparticles; dopamine detection; electrochemical oxidation; modified electrode; reduced graphene oxide.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
SEM images of RGO (A), Cu2O (B) and Cu2O-RGO composite nanoparticles (C).
Figure 2
Figure 2
Cyclic voltammograms (A) and Nyquist plots (B) of bare GCE, RGO, or Cu2O-RGO-modified GCEs in 5 × 10−3 mol/L [Fe(CN)6]3−/4− solution. The CVs was recorded in 0.1 M PBS (pH = 3.5) at the scan rate of 100 mV/s. The Nyquist plots was measured with alternating current (AC) amplitude of 5 mV, from 1 × 105 Hz to 0.1 Hz at their open circuit voltage.
Figure 3
Figure 3
Optimization of reduction potential (A) and reduction time (B) for electrochemical reduction of Cu2O-GO nanocomposites.
Figure 4
Figure 4
Cyclic voltamogramms obtain for 1 × 10−5 mol/L dopamine on bare GCE, RGO/GCE, and Cu2O-RGO/GCE in the presence of 0.1 M PBS (pH = 3.5) as supporting electrolyte. Scan rate: 0.1 V/s.
Figure 5
Figure 5
(A) The effect of pH on the oxidation peak current of 1 × 10−5 mol/L DA; and (B) the linear relationship between oxide peak potential and pH.
Figure 6
Figure 6
The effect of accumulation potential (A) and accumulation time (B) on the oxidation peak current of 1 × 10−5 mol/L DA.
Figure 7
Figure 7
The effect of scan rate (v) on the peak current of 1 × 10−5 mol/L DA. (A) CVs of 1 × 10−5 mol/L DA on the Cu2O-RGO/GCE recorded in 0.1 M PBS with different scan rates (v); and (B) linear relationship between peak currents and scan rate (v).
Figure 8
Figure 8
The SDLSV of DA (1 × 10−5 mol/L) on the Cu2O-RGO/GCE in the presence of AA (1 × 10−5 mol/L), and UA (1 × 10−5 mol/L). P0, P1, and P2 denotes the peak potentials of AA, DA, and UA, respectively. Scan potential range: 0~1.1 V; scan rate: 100 mV/s; supporting electrolytes: 0.1 M PBS.
Figure 9
Figure 9
The linear relationship between the oxidation peak ipa and the concentration of DA in the range of 1 × 10−8 mol/L~1 × 10−6 mol/L (A) and 1 × 10−6 mol/L~8 × 10−5 mol/L (B).
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References

    1. Liu A., Honma I., Zhou H. Amperometric biosensor based on tyrosinase-conjugated polysacchride hybrid film: Selective determination of nanomolar neurotransmitters metabolite of 3,4-dihydroxyphenylacetic acid (DOPAC) in biological fluid. Biosens. Bioelectron. 2005;21:809–816. doi: 10.1016/j.bios.2005.03.005. - DOI - PubMed
    1. Ensafi A.A., Taei M., Khayamian T., Arabzadeh A. Highly selective determination of ascorbic acid, dopamine, and uric acid by differential pulse voltammetry using poly (sulfonazo III) modified glassy carbon electrode. Sens. Actuators B: Chem. 2010;147:213–221. doi: 10.1016/j.snb.2010.02.048. - DOI
    1. Revin S.B., John S.A. Highly sensitive determination of uric acid in the presence of major interferents using a conducting polymer film modified electrode. Bioelectrochemistry. 2012;88:22–29. doi: 10.1016/j.bioelechem.2012.05.005. - DOI - PubMed
    1. Moghadam M.R., Dadfarnia S., Shabani A.M.H., Shahbazikhah P. Chemometric-assisted kinetic–spectrophotometric method for simultaneous determination of ascorbic acid, uric acid, and dopamine. Anal. Biochem. 2011;410:289–295. doi: 10.1016/j.ab.2010.11.007. - DOI - PubMed
    1. Li Y., Lin X. Simultaneous electroanalysis of dopamine, ascorbic acid and uric acid by poly (vinyl alcohol) covalently modified glassy carbon electrode. Sens. Actuators B: Chem. 2006;115:134–139. doi: 10.1016/j.snb.2005.08.022. - DOI

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