Silver Nanoparticles Modified Electrodes for Electroanalysis: An Updated Review and a Perspective

2022 ◽  
pp. 107166
Author(s):  
Azhar Abbas ◽  
Hatem M.A. Amin
2021 ◽  
Author(s):  
◽  
Lekhetho Simon Mpeta

Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.


NANO ◽  
2021 ◽  
Author(s):  
Saira Naz ◽  
Amjad Nisar ◽  
Lizhi Qian ◽  
Shafqat Hussain ◽  
Shafqat Karim ◽  
...  

The development of a highly sensitive and selective electrocatalyst for the detection of diclofenac sodium (D.S.) has remained a great challenge. In this work, graphene oxide functionalized with silver nanoparticles and zinc oxide (Ag–ZnO–GO) electrocatalyst was developed and investigated for the detection of D.S. The Ag–ZnO–GO/glassy carbon electrode exhibits high sensitivity and fast response within 3[Formula: see text]s owing to the efficient oxidation of D.S. at a very low potential at 0.25[Formula: see text]V. Moreover, the electrode shows a low detection limit of 0.02[Formula: see text][Formula: see text]M ([Formula: see text]) and long-term stability. To explore the synergic effects, the measurements of D.S. using GO, ZnO and ZnO–GO modified electrodes were also performed. The results demonstrate that the Ag–ZnO–GO nanocomposite electrode exhibits enhanced sensitivity and selectivity compared to the other electrodes. In addition, the electrode reveals excellent results for D.S. detection in the real samples as well. The enhanced performance of the proposed electrode is attributed to the improved electron transfer ability and synergic effects of the plasmonic Ag NPs and ZnO–GO structure. It is expected that Ag–ZnO–GO composite is a promising candidate for the construction of cost-effective electrochemical biosensors for medical and industrial applications.


2018 ◽  
Vol 20 (3) ◽  
pp. 1608-1614 ◽  
Author(s):  
Xiaosheng Cai ◽  
Eden E. L. Tanner ◽  
Chuhong Lin ◽  
Kamonwad Ngamchuea ◽  
John S. Foord ◽  
...  

Reduction of hydrogen peroxide on silver nanoparticle modified electrodes in the neutral solution proceeds through a CE mechanism.


2021 ◽  
Vol 317 ◽  
pp. 208-213
Author(s):  
Nurul Izrini Ikhsan ◽  
Nurul Ain Mohamed Zamri

Here, we report the synthesis of silver nanoparticles-reduced graphene oxide (AgNPs-rGO) hybrid for simple and eco-friendly method. Silver nanoparticles (AgNPs) were successfully deposited on reduced graphene oxide (rGO) sheets to form (AgNPs-rGO) hybrid using lemon extract as a reducing and stabilizing agent. The products form a stable aqueous solution without any surfactant stabilizers and this makes it possible to produce (AgNPs-rGO) hybrid on a large scale using low-cost solution processing technique. The synthesis of nanohybrid was examed at different ratio of reducing agent (1:1, 1:2, 1:4) and characterized using UV-Visible (UV-Vis) absorption spectrum, X-ray diffraction (XRD), Raman spectroscopy analyses and transmission electron microscopy (TEM) analyses. From UV-Vis absorption spectrum, the (AgNPs-rGO) (1:1) hybrid result shows the sharp peak at 433 nm indicating the accomplishment formation of AgNPs on the surface of rGO sheets. Crystalline and spherical AgNPs with an average particle size of 21 nm were found in the (AgNPs-rGO) hybrid with the assistance of 1:1 reducing agent. Furthermore, (AgNPs-rGO) (1:1) hybrid exhibit fast electron-transfer kinetics for electrochemical reaction of Fe (CN)63-/4- redox couple compared to other controlled modified electrodes, suggesting the potential applications for electrocatalysis and electrochemical sensor.


2011 ◽  
Vol 83 (11) ◽  
pp. 2041-2053 ◽  
Author(s):  
Shanmugam Manivannan ◽  
Ramasamy Ramaraj

Metal nanoparticles encapsulated by silicate sol-gel matrix find numerous applications particularly in electrocatalysis and sensors. In our previous reports, we have reported the mono- and bi-metal gold, silver, and core/shell gold/silver nanoparticles embedded in functionalized silicate sol-gel matrices. Modified electrodes were fabricated using mono- and bi-metallic gold, silver, and core/shell gold/silver nanoparticles embedded in silicate sol-gel, and they were used for the electrocatalysis and sensing of H2O2 and simultaneous detection of hydrazine, sulfite, and nitrite. We have prepared the gold nanoparticles encapsulated by amine-functionalized silicate sol-gel matrix in a single step without using any external reducing agents. The gold nanoparticles were also synthesized by using amine-functionalized silane monomer in the presence of β-cyclodextrin (β-CD), resulting in metal/polymer core/shell nanostructures. This nanocomposite material showed a synergistic stabilizing effect when compared to either silicate sol-gel matrix or β-CD alone as stabilizer. The synthesized gold nanoparticles were characterized using UV–vis spectroscopy and high-resolution transmission electron microscopy. Modified electrodes were prepared by using the gold nanoparticles embedded in silicate sol-gel matrix, and their electrochemical characteristics were studied.


2019 ◽  
Vol 107 (3) ◽  
pp. 305
Author(s):  
Mengmei Geng ◽  
Yuting Long ◽  
Tongqing Liu ◽  
Zijuan Du ◽  
Hong Li ◽  
...  

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.


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