scholarly journals New Generation of Electrochemical Sensors Based on Multi-Walled Carbon Nanotubes

2018 ◽  
Vol 8 (10) ◽  
pp. 1925 ◽  
Author(s):  
Thiago Oliveira ◽  
Simone Morais

Multi-walled carbon nanotubes (MWCNT) have provided unprecedented advances in the design of electrochemical sensors. They are composed by sp2 carbon units oriented as multiple concentric tubes of rolled-up graphene, and present remarkable active surface area, chemical inertness, high strength, and low charge-transfer resistance in both aqueous and non-aqueous solutions. MWCNT are very versatile and have been boosting the development of a new generation of electrochemical sensors with application in medicine, pharmacology, food industry, forensic chemistry, and environmental fields. This work highlights the most important synthesis methods and relevant electrochemical properties of MWCNT for the construction of electrochemical sensors, and the numerous configurations and successful applications of these devices. Thousands of studies have been attesting to the exceptional electroanalytical performance of these devices, but there are still questions in MWCNT electrochemistry that deserve more investigation, aiming to provide new outlooks and advances in this field. Additionally, MWCNT-based sensors should be further explored for real industrial applications including for on-line quality control.

2019 ◽  
Vol 7 (2) ◽  
pp. 764-774 ◽  
Author(s):  
Xuncai Chen ◽  
Zixun Yu ◽  
Li Wei ◽  
Zheng Zhou ◽  
Shengli Zhai ◽  
...  

Carbon nanotubes increase electrochemically active surface area and reduce charge transfer resistance of transition metal borides.


RSC Advances ◽  
2016 ◽  
Vol 6 (116) ◽  
pp. 115317-115325 ◽  
Author(s):  
Yaru Yan ◽  
Qitong Huang ◽  
Chan Wei ◽  
Shirong Hu ◽  
Hanqiang Zhang ◽  
...  

Cyclic voltammetry of HQ and CC recorded on Nafion/CDs–ZnO/MWCNTs/GCE.


2013 ◽  
Vol 663 ◽  
pp. 297-302 ◽  
Author(s):  
Shu Ai Yang ◽  
Xue Jiang ◽  
Yang Jun Dong ◽  
Ning Ning Zhu ◽  
Yuan Feng Wang

Multi-walled carbon nanotubes (MWNTs) combining with ferroferric oxide (Fe3O4) nanoparticles were used for electrochemical determination of bisphenol A (BPA). Fe3O4 nanoparticles with an average size of about 12 nm were synthesized. It was found that the Fe3O4-MWNTs nanocomposites-modified electrode could remarkably enhance the oxidation current of BPA. Chronoamperometry studies reveal that the amperometric response is rapid, stable, and offers a linear dependence over a range of BPA concentrations from 0.1 to 4 M. The proposed method can be used for evaluation of BPA in water samples. The electrochemical properties of the Fe3O4-MWNT nanocomposites are reasonably envisaged to be promising for providing a nanostructured platform in the development of electrochemical sensors or biosensors.


Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 115
Author(s):  
Suxing Luo ◽  
Meizhi Yang ◽  
Yuanhui Wu ◽  
Jiang Li ◽  
Jun Qin ◽  
...  

Owing to its ubiquity in natural water systems and the high toxicity of its accumulation in the human body, it is essential to develop simple and low-cost electrochemical sensors for the determination of 3,3′,5,5′-tetrabromobisphenol A (TBBPA). In this work, Fe3O4–activated biochar, which is based on excess sludge, was prepared and characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and BET analysis to analyze its basic features. Subsequently, it was used to fabricate an electrochemical sensor for the detection of TBBPA. The electrochemical test results revealed that the Fe3O4–activated biochar film exhibited a larger active surface area, a lower charge transfer resistance and a higher accumulation efficiency toward TBBPA. Consequently, the peak current of TBBPA was significantly enhanced on the surface of the Fe3O4–activated biochar. The TBBPA sensing platform developed using the Fe3O4–activated biochar composite film, with relatively a lower detection limit (3.2 nM) and a wider linear range (5–1000 nM), was successfully utilized to determine TBBPA levels in water samples. In summary, the effective application of Fe3O4–activated biochar provided eco-friendly and sustainable materials for the development of a desirable high-sensitivity sensor for TBBPA detection.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 476
Author(s):  
Xu Zhang ◽  
Jiuhan Zheng ◽  
Lusheng Xu ◽  
Ming Yin ◽  
Guoliang Zhang ◽  
...  

Novel high-quality thin film nanocomposite (TFN) membranes for enhanced forward osmosis (FO) were first synthesized through organic phase controlled interfacial polymerization by utilizing functional multi-walled carbon nanotubes (MWCNTs). As 3-aminopropyltriethoxysilane (APTES) grafted MWCNTs via an amidation reaction significantly promoted the dispersion in organic solution, MWCNTs-APTES with better compatibility effectively restricted the penetration of trimesoyl chloride (TMC), thus adjusting the morphology and characters of TFN membranes. Various techniques such as Fourier transform infrared spectra (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), sessile droplet analysis and FO experiments and reverse osmosis (RO) operation were taken to characterize and evaluate the performance of nanocomposites and membranes. The prepared TFN FO membranes exhibited good hydrophilicity and separation efficiency, in which water flux was about twice those of thin film composite (TFC) membranes without MWCNTs-APTES in both AL-DS and AL-FS modes. Compared with the original TFC membrane, the membrane structural parameter of the novel TFN FO membrane sharply was cut down to 60.7%. Based on the large number of low mass-transfer resistance channels provided by functional nanocomposites, the progresses may provide a facile approach to fabricate novel TFN FO membranes with advanced selectivity and permeability.


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1388
Author(s):  
Jing-Wen Xu ◽  
Zhuo-Miao Cui ◽  
Zhan-Qing Liu ◽  
Feng Xu ◽  
Ya-Shao Chen ◽  
...  

An electrochemical sensor for detection of the content of aspartame was developed by modifying a glassy carbon electrode (GCE) with multi-walled carbon nanotubes decorated with zinc oxide nanoparticles and in-situ wrapped with poly(2-methacryloyloxyethyl ferrocenecarboxylate) (MWCNTs@ZnO/PMAEFc). MWCNTs@ZnO/PMAEFc nanohybrids were prepared through reaction of zinc acetate dihydrate with LiOH·H2O, followed by reversible addition-fragmentation chain transfer polymerization of 2-methacryloyloxyethyl ferrocenecarboxylate, and were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Raman, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), scanning electron microscope (SEM), and transmission electron microscope (TEM) techniques. The electrochemical properties of the prepared nanohybrids with various composition ratios were examined by cyclic voltammetry (CV), and the trace additives in food and/or beverage was detected by using differential pulse voltammetry (DPV). The experimental results indicated that the prepared nanohybrids for fabrication of electrochemical modified electrodes possess active electroresponse, marked redox current, and good electrochemical reversibility, which could be mediated by changing the system formulations. The nanohybrid modified electrode sensors had a good peak current linear dependence on the analyte concentration with a wide detection range and a limit of detection as low as about 1.35 × 10−9 mol L−1, and the amount of aspartame was measured to be 35.36 and 40.20 µM in Coke zero, and Sprite zero, respectively. Therefore, the developed nanohybrids can potentially be used to fabricate novel electrochemical sensors for applications in the detection of beverage and food safety.


Cellulose ◽  
2021 ◽  
Author(s):  
Katsuhide Fujita ◽  
Sawae Obara ◽  
Junko Maru ◽  
Shigehisa Endoh

Abstract Safety assessment of cellulose nanofibrils (CNFs) is required to accelerate the utilization of these materials in industrial applications. The present study aimed to characterize the effects on rat pulmonary inflammation over a period of 90 days following intratracheal instillation of three types of CNFs or multi-walled carbon nanotubes (MWCNTs) at doses of 0.5, 1.0, or 2.0 mg/kg. The pulmonary inflammatory responses induced by phosphorylated CNFs (CNF1), 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized CNFs (CNF2), CNFs produced via mechanical defibrillation (CNF3), and MWCNTs were investigated using bronchoalveolar lavage fluid analysis, histopathological findings, and comprehensive gene expression profiling of rat lungs. CNF1 and CNF2 with approximately equal diameter (7.0–8.0 nm) and length (0.8–1.0 µm) distributions induced inflammation after dosing, which was attenuated 90 days post-instillation. CNF3 of relatively greater thickness (21.2 nm) and longer length (1.7 μm) deposited around the terminal bronchioles were observed after instillation. Acute inflammatory responses in the alveoli induced by CNF3 were mild compared with those induced by other materials and attenuated 90 days post-instillation. MWCNTs induced severe pulmonary inflammatory responses that continued during the test period. The inflammation failed to resolve within 90 days post-instillation. A hierarchical cluster analysis revealed comparable gene expression profiles for CNF1, CNF2, and CNF3, whereas profiles of MWCNTs were different from those of other test substances. This study suggests that pulmonary inflammation is associated with the diameter and length distributions of CNFs and that the pulmonary inflammation caused by CNFs is mild compared with that caused by MWCNTs. Graphic abstract


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