Determination of Uric Acid in Co-Presence of Dopamine and Ascorbic Acid Using Cuprous Oxide Nanoparticle-Functionalized Graphene Decorated Glassy Carbon Electrode

Abstract

Cuprous oxide nanoparticles (Cu 2 O NPs) were dispersed into a graphene oxide (GO) solution to form a homogeneous Cu 2 O-GO dispersion. After this, the cuprous oxide nanoparticles were functionalized to electrochemically reduce the graphene oxide decorated glassy carbon electrode (Cu 2 O-ErGO/GCE). This was prepared by coating the Cu 2 O-GO dispersion onto the surface of the glassy carbon electrode (GCE), which was followed by a potentiostatic reduction process. An irreversible two-electron reaction of uric acid (UA) was observed at the voltammetric sensor. Moreover, the high concentrations of dopamine (DA) and ascorbic acid (AA) hardly affected the peak current of UA, which suggested that Cu 2 O-ErGO/GCE have excellent selectivity for UA. This is probably because the response peaks of the three compounds are well-separated from each other. The oxidation peak current was proportional to the concentration of UA in the ranges of 2.0 nM−0.6 µM and 0.6 µM−10 µM, respectively, with a low limit of detection (S/N = 3, 1.0 nM) after an accumulation time of 120 s. Cu 2 O-ErGO/GCE was utilized for the rapid detection of UA in human blood serum and urine samples with satisfactory results. when detecting UA with bare electrodes since they have similar oxidation peak potentials [10][11][12]. Nanocomposite-modified electrodes can improve the anti-interference performance and selectivity, which is a common method that is used to solve this problem. At present, many chemically modified electrodes have been proposed for the determination of UA [9,[13][14][15][16][17][18][19][20][21][22] although their selectivity is limited, especially due to the coexistence of DA and AA. Hence, developing a modified electrode with high sensitivity and selectivity to meet clinical demands is still challengeable and desirable.Catalysts 2018, 8, x FOR PEER REVIEW 2 of 15 potentials [10][11][12]. Nanocomposite-modified electrodes can improve the anti-interference performance and selectivity, which is a common method that is used to solve this problem. At present, many chemically modified electrodes have been proposed for the determination of UA [9,[13][14][15][16][17][18][19][20][21][22] although their selectivity is limited, especially due to the coexistence of DA and AA. Hence, developing a modified electrode with high sensitivity and selectivity to meet clinical demands is still challengeable and desirable. Scheme 1. The reaction mechanism of UA.In the past few years, transition metals and metal oxides have received increasing attention in many fields, such as sensors and electrocatalysis, due to their unique sensing performance and superior electrocatalytic activity [9,11,23,24]. Among these metal oxides, cuprous oxide (Cu2O) is a new type of p-type semiconductor with a narrow band gap, which can also be easily excited by visible light. Due to their outstanding advantages, such as non-toxic, low cost and stable photochemical properties, Cu2O nanoparticles have been extensively used in many fields, such as new energy, photocatalytic degradation, ...

Sol-Gel Mediated Greener Synthesis of γ-Fe2O3 Nanostructures for the Selective and Sensitive Determination of Uric Acid and Dopamine

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Synergy of Photocatalysis and Adsorption for Simultaneous Removal of Hexavalent Chromium and Methylene Blue by g-C3N4/BiFeO3/Carbon Nanotubes Ternary Composites

“…The optical properties of a material directly affect its light absorption capacity [44]. In this work, UV-visible diffuse reflection studies of g-C 3 N 4 , BiFeO 3 , CNB, and CNBT were performed to examine their light absorption characteristics.…”

Application of carboxylic acid-functionalized of graphene oxide for electrochemical simultaneous determination of tryptophan and tyrosine in milk

“…Chemical modification of electrodes with suitable materials could solve these problems. Commonly, many nano structure materials such as polymer a nanocomposite [20][21][22][23][24][25], metal nanoparticles [26][27][28], and graphene nanocomposite [15,[29][30][31][32][33][34][35] have been introduced to enhance the electrode performance.…”

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