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

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2876
Author(s):  
Threrawee Sanglaow ◽  
Pattanan Oungkanitanon ◽  
Piyapong Asanithi ◽  
Thana Sutthibutpong

The selectivity in the simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) has been an open problem in the biosensing field. Many surface modification methods were carried out for glassy carbon electrodes (GCE), including the use of graphene oxide and amino acids as a selective layer. In this work, molecular dynamics (MD) simulations were performed to investigate the role of serine oligomers on the selectivity of the AA, DA, and UA analytes. Our models consisted of a graphene oxide (GO) sheet under a solvent environment. Serine tetramers were added into the simulation box and were adsorbed on the GO surface. Then, the adsorption of each analyte on the mixed surface was monitored from MD trajectories. It was found that the adsorption of AA was preferred by serine oligomers due to the largest number of hydrogen-bond forming functional groups of AA, causing a 10-fold increase of hydrogen bonds by the tetraserine adsorption layer. UA was the least preferred due to its highest aromaticity. Finally, the role of hydrogen bonds on the electron transfer selectivity of biosensors was discussed with some previous studies. AA radicals received electrons from serine through hydrogen bonds that promoted oxidation reaction and caused the negative shifts and separation of the oxidation potential in experiments, as DA and UA were less affected by serine. Agreement of the in vitro and in silico results could lead to other in silico designs of selective layers to detect other types of analyte molecules.

Author(s):  
Threravee Sanglao ◽  
Pattanan Oungkanitanon ◽  
Piyapong Asanithi ◽  
Thana Sutthibutpong

The selectivity in the simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) has been an open problem in the biosensing field. Many surface modification methods were carried out for glassy carbon electrodes (GCE), including the use of graphene oxide and amino acids as a selective layer. In this work, molecular dynamics (MD) simulations were performed to investigate the role of serine oligomers on the selectivity of the AA, DA, UA analytes. Our models consisted of a graphene oxide (GO) sheet under a solvent environment. Serine tetramers were added into the simulation box and were adsorbed on the GO surface. Then, the adsorption of each analyte on the mixed surface was monitored from MD trajectories. It was found that the adsorption of AA was preferred by serine oligomers due to the largest number of hydrogen-bond forming functional groups of AA, while UA was the least preferred due to its highest aromaticity. Finally, the role of hydrogen bonds on the electron transfer selectivity of biosensors was discussed with some previous studies.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4427
Author(s):  
Daria Minta ◽  
Zoraida González ◽  
Piotr Wiench ◽  
Stanisław Gryglewicz ◽  
Grażyna Gryglewicz

Gold nanoparticles (AuNPs) were homogeneously electrodeposited on nitrogen-doped reduced graphene oxide (N-rGO) to modify a glassy carbon electrode (GCE/N-rGO-Au) in order to improve the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA). N-rGO was prepared by the hydrothermal treatment of graphene oxide (GO) and urea at 180 °C for 12 h. AuNPs were subsequently electrodeposited onto the surface of GCE/N-rGO using 1 mM HAuCl4 solution. The morphology and chemical composition of the synthesized materials were characterized by field-emission scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical performance of the modified electrodes was investigated through cyclic voltammetry and differential pulse voltammetry measurements. Compared to GCE/rGO-Au, GCE/N-rGO-Au exhibited better electrochemical performance towards the simultaneous detection of the three analytes due to the more homogeneous distribution of the metallic nanoparticles as a result of more efficient anchoring on the N-doped areas of the graphene structure. The GCE/N-rGO-Au-based sensor operated in a wide linear range of DA (3–100 µM), AA (550–1500 µM), and UA (20–1000 µM) concentrations with a detection limit of 2.4, 58, and 8.7 µM, respectively, and exhibited satisfactory peak potential separation values of 0.34 V (AA-DA), 0.20 V, (DA-UA) and 0.54 V (AA-UA). Remarkably, GCE/N-rGO-Au showed a very low detection limit of 385 nM towards DA, not being susceptible to interference, and maintained 90% of its initial electrochemical signal after one month, indicating an excellent long-term stability.


2021 ◽  
Vol 83 (3) ◽  
pp. 85-92
Author(s):  
Azleen Rashidah Mohd Rosli ◽  
Farhanini Yusoff ◽  
Saw Hong Loh ◽  
Hanis Mohd Yusoff ◽  
Muhammad Mahadi Abdul Jamil ◽  
...  

A magnetic nanoparticles/reduced graphene oxide modified glassy carbon electrode (MNP/rGO/GCE) was fabricated via one-step facile synthesis route for the simultaneous determination of ascorbic acid (AA), dopamine (DA), along with uric acid (UA). A series of diseases and disorders has been associated with irregular levels of these respective analytes, thus early detection is highly crucial. Physical and electrochemical characterization of the modified electrode was conducted by using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) analysis, X-Ray Diffraction (XRD) analysis and Brauneur-Emmet-Teller (BET), Cyclic Voltammetry (CV) and Electron Impedance Spectroscopy (EIS). The results obtained confirmed the formation of MNP/rGO composite. Differential pulse voltammetry (DPV) of MNP/rGO/GCE displays three well-defined peaks which associated to AA, DA and UA, respectively. The response towards DA is linear in the concentration range of 15 nM to 100 µM with a detection limit of 0.19 nM while a response to AA and UA is also linear in the concentration range of 10 µM to 100 µM with a limit of detection 0.22 µM and 45 nM respectively. The proposed modified electrode offers a good response towards simultaneous detection of three different electroactive species with excellent electron transfer rate, great capacitance and ideal diffusive control behavior.


Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1256 ◽  
Author(s):  
Zouhour Hsine ◽  
Salma Bizid ◽  
Rym Mlika ◽  
Hélène Sauriat-Dorizon ◽  
Ayoub Haj Said ◽  
...  

In this study, an efficient and simple designed nanohybrid created for individual and simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). This nanohybrid is a combination of chemical reduced graphene oxide (CRGO) and redox poly(para-phenylene) (Fc-ac-PP) modified in a lateral position with ferrrocenyl group CRGO/Fc-ac-PPP. The CRGO/Fc-ac-PPP nanohybrid demonstrated a synergistic effect resulting in a large conductivity, surface area and catalytic properties provided by the redox attached ferrocene. Moreover, this nanocomposite is able to detect individually as well as simultaneously AA, DA and UA in a co-existence system with defined and separated redox peaks oxidation. The linear response ranges for AA, DA and UA, when detected simultaneously, are 0.1–10000 μM, 0.0001–1000 μM and 0.1–10000 μM, respectively, and the detection limits (S/N = 3) are 0.046 μM, 0.2 nM and 0.013 μM, respectively. The proposed sensor shown satisfactory results when applied to real spiked urine samples for measuring the abnormal high or lowconcentration of AA, DA and UA in vivo.


RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 96467-96478 ◽  
Author(s):  
P. Muthukumaran ◽  
C. Sumathi ◽  
J. Wilson ◽  
G. Ravi

In this study, marigold flower-like self-assembled β-NiS (nickel sulfide) nanosheets were grown on rGO (reduced graphene oxide) by a single-step hydrothermal process and then gold nanospheres (AuNS) were electrochemically deposited on the β-NiS@rGO nanostructures.


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