scholarly journals Influence of Nitrogen-Doped Carbon Dot and Silver Nanoparticle Modified Carbon Paste Electrodes on the Potentiometric Determination of Tobramycin Sulfate: A Comparative Study

Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 52
Author(s):  
Nermine V. Fares ◽  
Passant M. Medhat ◽  
Christine M. El Maraghy ◽  
Sherif Okeil ◽  
Miriam F. Ayad

Two inexpensive and simple methods for synthesis of carbon nanodots were applied and compared to each other, namely a hydrothermal and microwave-assisted method. The synthesized carbon nanodots were characterized using transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis), photoluminescence (PL), Fourier transform-infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The synthesized microwave carbon nanodots had smaller particle size and were thus chosen for better electrochemical performance. Therefore, they were used for our modification process. The proposed electrodes performance characteristics were evaluated according to the IUPAC guidelines, showing linear response in the concentration range 10−6–10−2, 10−7–10−2, and 10−8–10−2 M of tobramycin with a Nernstian slope of 52.60, 58.34, and 57.32 mV/decade for the bare, silver nanoparticle and carbon nanodots modified carbon paste electrodes, respectively. This developed potentiometric method was used for quantification of tobramycin in its co-formulated dosage form and spiked human plasma with good recovery percentages and without interference of the co-formulated drug loteprednol etabonate and excipients.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. K. Shashikumara ◽  
Bhimanagouda Kalaburgi ◽  
B. E. Kumara Swamy ◽  
H. Nagabhushana ◽  
S. C. Sharma ◽  
...  

AbstractThe RGO-Y2O3 and RGO-Y2O3: Cr3+ (5 mol %) nanocomposite (NC) synthesized by hydrothermal technique. The structure and morphology of the synthesized NCs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Y2O3:Cr3+ displays spherical-shaped particles. Conversely, the surface of the RGO displays a wrinkly texture connecting with the existence of flexible and ultrathin graphene sheets. The photoluminescence (PL) emission spectra showed series of sharp peaks at 490, 591, and 687 nm which corresponding to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2, and 4F9/2 → 6H11/2 transitions and lies in the blue, orange, and red region. The prepared NCs were used for the preparation of modified carbon paste electrodes (MCPE) in the electrochemical detection of dopamine (DA) at pH 7.4. Both modified electrodes provide a good current response towards voltammetric detection of DA. Doping is an effective method to improve the conductivity of Y2O3:Cr3+ and developed a method for the sensor used in analytical applications.


2021 ◽  
Author(s):  
J Shashikumar ◽  
Bheenama Patil ◽  
B E KUMARA SWAMY ◽  
H Nagabhushana ◽  
S Sharma ◽  
...  

Abstract The RGO-Y2O3 and RGO-Y2O3: Cr3+ (5 mol %) nanocomposite (NC) synthesized a simple hydrothermal technique. The structure and morphology of the synthesized NCs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Y2O3:Cr3+ display spherical shaped particles. Conversely, the surface of the RGO displays a wrinkly texture connecting with the existence of flexible and ultrathin graphene sheets. The photoluminescence (PL) emission spectra showed series of sharp peaks at 490, 591, and 687 nm which corresponding to 4F9/2→6H15/2, 4F9/2→6H13/2, and 4F9/2→6H11/2 transitions and lies in the blue, orange, and red region. The prepared NCs were used for the preparation of modified carbon paste electrodes (MCPE) in the electrochemical detection of dopamine (DA) at pH 7.4. Both modified electrodes provide a good electrocatalytic activity for the voltametric detection of DA. Doping is an effective method to improve the conductivity of Y2O3:Cr3+ and developed a method for the sensor used in analytical applications.


2011 ◽  
Vol 64 (2) ◽  
pp. 197 ◽  
Author(s):  
Zhangang Han ◽  
Jingjing Wu ◽  
Yuanzhe Gao ◽  
Xueliang Zhai

Three novel V-centred Keggin-based compounds containing cap-shaped Sb atoms: (HDMF)2[(VO4)W5.65V7.74Sb2.61O36.77]·6H2O (1), [Co(phen)3]2[(VO4)Mo9.58V2.42Sb2O36]·6H2O (2) and [Ni(phen)2(H2O)]2[(VO4)Mo8V4Sb2O36]·2H2O (3) (DMF = dimethylformamide; phen = 1,10-phenanthroline) have been synthesized and characterized. X-ray diffraction analysis revealed that compound 1 consists of an unusually one-dimensional 12-tungstovanadate Keggin-based polymer, in which the reduced tungstovanadate Keggin species are stabilized by introducing capping {VO} and {Sb} groups and then linked into chains via V(Sb)–O–V(Sb) interactions. Both 2 and 3 are built from secondary metal–ligand groups (Co-phen for 2, Ni-phen for 3) and 12-molybdovanadate doped Keggin-type cores with two antimony atoms capping two opposite sites. The anion in 3 represents a bi-capped and bi-supported Keggin-type structure. The electrochemical properties of 2- and 3-modified carbon paste electrodes (2-CPE and 3-CPE) are also studied.


2006 ◽  
Vol 591 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Iwona Szymańska ◽  
Hanna Radecka ◽  
Jerzy Radecki ◽  
Philip A. Gale ◽  
Colin N. Warriner

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2817 ◽  
Author(s):  
Vinod Gupta ◽  
Hassan Karimi-Maleh ◽  
Shilpi Agarwal ◽  
Fatemeh Karimi ◽  
Majede Bijad ◽  
...  

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.


1999 ◽  
Vol 382 (1-2) ◽  
pp. 179-188 ◽  
Author(s):  
M.Mar Ortiz Viana ◽  
M.Pilar da Silva ◽  
Raquel Agraz ◽  
Jesús R. Procopio ◽  
M.Teresa Sevilla ◽  
...  

2006 ◽  
Vol 18 (6) ◽  
pp. 559-572 ◽  
Author(s):  
Mitk'El B. Santiago ◽  
Meredith M. Vélez ◽  
Solmarie Borrero ◽  
Agustín Díaz ◽  
Craig A. Casillas ◽  
...  

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