Biomimetic Polymer-Based Electrochemical Sensor Using Methyl Blue-Adsorbed Reduced Graphene Oxide and Functionalized Multiwalled Carbon Nanotubes for Trace Sensing of Cyanocobalamin

2018 ◽  
Vol 1 (9) ◽  
pp. 4652-4660 ◽  
Author(s):  
Richa Singh ◽  
Swadha Jaiswal ◽  
Kislay Singh ◽  
Sana Fatma ◽  
Bhim Bali Prasad
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Reduced Graphene Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Methyl Blue ◽  
Multiwalled Carbon ◽  
Reduced Graphene ◽  
Biomimetic Polymer ◽  
Functionalized Multiwalled Carbon Nanotubes

scholarly journals Development of Electrochemical Sensor Based on Carbonaceal and Metal Phthalocyanines Materials for Determination of Ethinyl Estradiol

Chemosensors ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 32 ◽  
Author(s):  
Malena Karla Lombello Coelho ◽  
Daniela Nunes da Silva ◽  
Arnaldo César Pereira
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
River Water ◽  
Reduced Graphene Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Ethinyl Estradiol ◽  
Multiwalled Carbon ◽  
Reduced Graphene

This work describes the development of an electrochemical sensor that was used in the determination of ethinyl estradiol (EE) in pharmaceutical formulations, river water, and milk using the square wave voltammetry technique. Studies were carried out using different carbonaceous materials (multiwalled carbon nanotubes, reduced graphene oxide Reduced graphene oxide, graphite) and different metallic phthalocyanines (cobalt, iron and manganese). Based on these studies it was possible to obtain the best system for the construction of the sensor. The device was obtained by the chemical modification of a glassy carbon electrode (GCE) with multiwalled carbon nanotubes (MWCNTs) and cobalt phthalocyanine (CoPc). The materials were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Under conditions previously optimized for the proposed method, an analytical curve was constructed, presenting linearity in a range of 2.50–90.0 μmol L−1 (R = 0.990), with detection limit of 2.20 μmol L−1 and quantification of 2.50 μmol L−1. The validation of the methodology for the determination of EE using GCE-MWCNTs-CoPc was performed, being accurate, precise, stable and sensitive. The recovery of ethinyl estradiol in the sample of pharmaceutical formulation was 103.93%, in the samples of river water ranged from 92.75% to 96.47%, and in the milk sample was from 88.00% to 96.20%. Thus, the proposed method presented a viable alternative for the determination of ethinyl estradiol in the quality control of pharmaceutical and food formulations as well as in environmental control.

scholarly journals Graphene oxide-multiwalled carbon nanotubes composite as an anode for lithium ion batteries

2016 ◽  
Vol 34 (3) ◽  
pp. 481-486 ◽  
Author(s):  
Łukasz Majchrzycki ◽  
Mariusz Walkowiak ◽  
Agnieszka Martyła ◽  
Mikhail Y. Yablokov ◽  
Marek Nowicki ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Lithium Ion Batteries ◽  
Reduced Graphene Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Functional Groups ◽  
Lithium Ion ◽  
Lithium Storage ◽  
Multiwalled Carbon ◽  
Reduced Graphene

AbstractNowadays reduced graphene oxide (rGO) is regarded as a highly interesting material which is appropriate for possible applications in electrochemistry, especially in lithium-ion batteries (LIBs). Several methods were proposed for the preparation of rGO-based electrodes, resulting in high-capacity LIBs anodes. However, the mechanism of lithium storage in rGO and related materials is still not well understood. In this work we focused on the proposed mechanism of favorable bonding sites induced by additional functionalities attached to the graphene planes. This mechanism might increase the capacity of electrodes. In order to verify this hypothesis the composite of non-reduced graphene oxide (GO) with multiwalled carbon nanotubes electrodes was fabricated. Electrochemical properties of GO composite anodes were studied in comparison with similarly prepared electrodes based on rGO. This allowed us to estimate the impact of functional groups on the reversible capacity changes. As a result, it was shown that oxygen containing functional groups of GO do not create, in noticeable way, additional active sites for the electrochemical reactions of lithium storage, contrary to what has been postulated previously.

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