Simultaneous Detection of Ascorbic Acid, Dopamine, and Uric Acid Using a Novel Electrochemical Sensor Based on Palladium Nanoparticles/Reduced Graphene Oxide Nanocomposite

Abstract

A fresh strategy based on two-step electrochemical reduction for the fabrication of palladium nanoparticles/reduced oxide nanocomposite-modified glass carbon electrode (PdNPs/rGO/GCE) was established in this study. Field emission scanning electron microscopy (FESEM) images showed that spherical PdNPs were evenly distributed on the surface of rGO-modified electrode (rGO/GCE), and the introduction of PdNPs has no effect on the morphology of rGO. Electrochemical impedance spectroscopy (EIS) studies revealed that the conductivity of PdNPs/rGO/GCE was higher than that of rGO/GCE and bare GCE. The electrochemical performances of PdNPs/rGO/GCE sensor were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry using ascorbic acid (AA), dopamine (DA), and uric acid (UA) as analytes. At the optimized conditions, wide linear ranges of 0.5–3.5 mM (R2 = 0.99), 3–15 μM (R2 = 0.99) and 15–42 μM (R2 = 0.99), and 0.3–1.4 mM (R2 = 0.99) towards AA, DA, and UA in ternary mixture were observed, respectively. In addition to superior anti-interference capability, fast response (≤5 s), excellent reproducibility, and good long-term stability were also given by this sensor. These results suggested that PdNPs/rGO/GCE is promising for the simultaneous detection of AA, DA, and UA in practical application.

Unveiling the Fundamental Mechanisms of Graphene Oxide Selectivity on the Ascorbic Acid, Dopamine, and Uric Acid by Density Functional Theory Calculations and Charge Population Analysis

“…1. Our DFT calculation using the GGA-PBE functional with vdW-DF2 correction found that the stability of GO5-zigzag-B > GO5-para > GO5-zigzag-A > GO5-armchair was with a similar trend to the previous DFT study [20]. The most stable epoxy-functionalized GO, GO5-zigzag-B, was with an epoxy group at the opposite side of the graphene plane from the other four epoxy groups.…”

“…These made graphene an ideal material for developing biosensors. A number of studies have reported the electrode modification to improve the simultaneous determination of AA, DA, and UA in the CV and differential pulse voltammetry (DPV) experiments [9][10][11][12][13][14][15][16][17][18][19][20][21], e.g., the use of multilayer graphene nanoflake films (MGNFs) [9], graphitic sheets or multi-walled carbon nanotube/metal composites [10,12,13,[16][17][18][19][20], and conducting polymers [11,14,15,21]. Moreover, electrical [22] and chemical [23] reduced graphene oxide (rGO) were also employed for AA/DA/UA detections due to the better conductivity than GO and their cost effectiveness.…”

Unveiling the Fundamental Mechanisms of Graphene Oxide Selectivity on the Ascorbic Acid, Dopamine, and Uric Acid by Density Functional Theory Calculations and Charge Population Analysis

“…These made graphene an ideal material for developing biosensors. Many studies have reported electrode modification to improve the simultaneous determination of AA, DA, and UA in the CV and differential pulse voltammetry (DPV) experiments [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], e.g., the use of multilayer graphene nanoflake films (MGNFs) [ 10 ], graphitic sheets or multi-walled carbon nanotube/metal composites [ 11 , 13 , 14 , 17 , 18 , 19 , 20 , 21 ], and conducting polymers [ 12 , 15 , 16 , 22 ]. Moreover, electrical [ 23 ] and chemical [ 24 ] reduced graphene oxides (rGO) were also employed for AA/DA/UA detections due to the better conductivity than GO and their cost-effectiveness.…”

Molecular Mechanisms on the Selectivity Enhancement of Ascorbic Acid, Dopamine, and Uric Acid by Serine Oligomers Decoration on Graphene Oxide: A Molecular Dynamics Study

“…The relatively low costs and simple measurement procedures, requiring a three-electrode system and a potentiostat to scan for the redox potentials that return the signal of molecules, led to the possibility of developing the portable sensing platforms [17][18][19]. Many studies showed that using a cyclic voltammetry (CV) or differential pulse voltammetry (DPV) with glassy carbon electrodes (GCE) can detect AA, DA, and UA up to the micromolar limit of detection [20][21][22]. However, these electrochemical techniques failed to simultaneously detect AA, DA, and UA due to overlapping oxidation peaks, which might cause false-positive detection cases in clinical uses [23][24][25].…”