scholarly journals Effective Adsorption and Sensitive Detection of Cr(VI) by Chitosan/Cellulose Nanocrystals Grafted with Carbon Dots Composite Hydrogel

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3788
Author(s):  
Hua Zeng ◽  
Zhiyuan Hu ◽  
Chang Peng ◽  
Lei Deng ◽  
Suchun Liu
Keyword(s):  
Cellulose Nanocrystals ◽  
Carbon Dots ◽  
Composite Hydrogel ◽  
Economic Feasibility ◽  
Sensitive Detection ◽  
Quantitative Detection ◽  
Maximum Adsorption Capacity ◽  
Public Attention ◽  
Adsorption Sites ◽  
Sorption Ability

Due to its lethal effect on the human body and other creatures, Cr(VI) ions have attained widespread public attention, and an effective adsorbent for removing Cr(VI) ions is vital. Chitosan (CS)/cellulose nanocrystals grafted with carbon dots (CNCD) composite hydrogel with strong sorption ability and sensitive detection ability for Cr(VI) was formed. The cellulose nanocrystals (CN) offered a natural skeleton for assembling 3D porous structures, and then improved the sorption ability for Cr(VI); moreover, carbon dots (CD) acted as a fluorescent probe for Cr(VI) and provided Cr(VI) adsorption sites. With a maximum adsorption capacity of 217.8 mg/g, the CS/CNCD composite hydrogel exhibited efficient adsorption properties. Meanwhile, with a detection limit of 0.04 μg/L, this hydrogel was used for selective and quantitative detection of Cr(VI). The determination of Cr(VI) was based on the inner filter effect (IFE) and static quenching. This hydrogel retained its effective adsorption ability even after four repeated regenerations. Furthermore, the economic feasibility of the CS/CNCD composite hydrogel over activated carbon was confirmed using cost analysis. This study provided one new method for producing low-cost adsorbents with effective sorption and sensitive detection for Cr(VI).

Rapid and sensitive detection of Salmonella typhimurium using aptamer-conjugated carbon dots as fluorescence probe

2015 ◽  
Vol 7 (5) ◽  
pp. 1701-1706 ◽  
Author(s):  
Renjie Wang ◽  
Yi Xu ◽  
Tao Zhang ◽  
Yan Jiang
Keyword(s):  
Salmonella Typhimurium ◽  
Carbon Dots ◽  
Fluorescence Probe ◽  
Sensitive Detection ◽  
Quantitative Detection ◽  
Carbon Dot

Aptamer-conjugated carbon dot complexes were developed and first used as a novel fluorescence probe for sensitive quantitative detection of Salmonella typhimurium.

scholarly journals A novel carbon dot/polyacrylamide composite hydrogel film for reversible detection of the antibacterial drug ornidazole

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22993-23001
Author(s):  
Weizhen Wu ◽  
Xiaoyi Wu ◽  
Miao He ◽  
Xiaolin Yuan ◽  
Jiaping Lai ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Composite Hydrogel ◽  
Quantitative Detection ◽  
Antibacterial Drug ◽  
Blue Fluorescence ◽  
Carbon Dot ◽  
Real Samples ◽  
Hydrogel Film

A novel carbon dot/polyacrylamide composite hydrogel film with stable blue fluorescence performance was fabricated by merging a hydrogel film and carbon dots, which was used for highly selective and quantitative detection of ONZ in real samples.

scholarly journals Adsorptive and Coagulative Removal of Trace Metals from Water Using Surface Modified Sawdust-Based Cellulose Nanocrystals

J ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 193-205
Author(s):  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Taile Leswifi ◽  
Maurice S. Onyango
Keyword(s):  
Trace Metals ◽  
Adsorption Capacity ◽  
Cellulose Nanocrystals ◽  
Inductively Coupled Plasma ◽  
Electrostatic Interactions ◽  
Natural Waters ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Major Drawback ◽  
Surface Modified

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

scholarly journals Synthesis of Silver-Impregnated Magnetite Mesoporous Silica Composites for Removing Iodide in Aqueous Solution

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 175
Author(s):  
Sang-Eun Jo ◽  
Jung-Weon Choi ◽  
Sang-June Choi
Keyword(s):  
Aqueous Solution ◽  
Langmuir Isotherm ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Maximum Adsorption Capacity ◽  
Initial Contact ◽  
Order Kinetic ◽  
Sorption Ability ◽  
High Sorption

Mag@silica-Ag composite has a high sorption ability for I− in aqueous solution due to its high surface area and strong affinity for the studied anion. The material adsorbed I− rapidly during the initial contact time (in 45 min, η = 80%) and reached adsorption equilibrium after 2 h. Moreover, mag@silica-Ag proved to selectively remove I− from a mixture of Cl−, NO3− and I−. The adsorption behavior fitted the Langmuir isotherm perfectly and the pseudo-second-order kinetic model. Based on the Langmuir isotherm, the maximum adsorption capacity of mag@silica-Ag was 0.82 mmol/g, which is significantly higher than previously developed adsorbents. This study introduces a practical application of a high-capacity adsorbent in removing radioactive I− from wastewaters.

scholarly journals Characterizing Bacterial Cellulose Produced byKomagataeibacter sucrofermentans H-110 on Molasses Medium and Obtaining a Biocomposite Based on It for the Adsorption of Fluoride

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1422
Author(s):  
Viktor V. Revin ◽  
Alexander V. Dolganov ◽  
Elena V. Liyaskina ◽  
Natalia B. Nazarova ◽  
Anastasia V. Balandina ◽  
...  
Keyword(s):  
Composite Material ◽  
Adsorption Capacity ◽  
Bacterial Cellulose ◽  
Functional Materials ◽  
Degree Of Crystallinity ◽  
Maximum Adsorption Capacity ◽  
Fluoride Ions ◽  
Sorption Ability ◽  
Wide Range ◽  
Biocomposite Material

Currently, there is an increased demand for biodegradable materials in society due to growing environmental problems. Special attention is paid to bacterial cellulose, which, due to its unique properties, has great prospects for obtaining functional materials for a wide range of applications, including adsorbents. In this regard, the aim of this study was to obtain a biocomposite material with adsorption properties in relation to fluoride ions based on bacterial cellulose using a highly productive strain of Komagataeibacter sucrofermentans H-110 on molasses medium. Films of bacterial cellulose were obtained. Their structure and properties were investigated by FTIR spectroscopy, NMR, atomic force microscopy, scanning electron microscopy, and X-ray structural analysis. The results show that the fiber thickness of the bacterial cellulose formed by the K. sucrofermentans H-110 strain on molasses medium was 60–90 nm. The degree of crystallinity of bacterial cellulose formed on the medium was higher than on standard Hestrin and Schramm medium and amounted to 83.02%. A new biocomposite material was obtained based on bacterial cellulose chemically immobilized on its surface using atomic-layer deposition of nanosized aluminum oxide films. The composite material has high sorption ability to remove fluoride ions from an aqueous medium. The maximum adsorption capacity of the composite is 80.1 mg/g (F/composite). The obtained composite material has the highest adsorption capacity of fluoride from water in comparison with other sorbents. The results prove the potential of bacterial cellulose-based biocomposites as highly effective sorbents for fluoride.

Convenient and sensitive detection of norfloxacin with fluorescent carbon dots

2014 ◽  
Vol 2 (45) ◽  
pp. 7964-7970 ◽  
Author(s):  
Manman Yang ◽  
Hao Li ◽  
Juan Liu ◽  
Weiqian Kong ◽  
Shunyan Zhao ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Sensitive Detection ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Carbon dots isolated from chromatographic fractions for sensing applications

RSC Advances ◽  
2015 ◽  
Vol 5 (129) ◽  
pp. 106838-106847 ◽  
Author(s):  
Lizhen Liu ◽  
Feng Feng ◽  
Man Chin Paau ◽  
Qin Hu ◽  
Yang Liu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Fluorescent Probes ◽  
Carbon Dots ◽  
Sensitive Detection ◽  
Sensing Applications

An as-synthesised C-dots sample derived from acetic acid, NAC and P2O5 can be separated and fractionated into various C-dots species by HPLC. The brighter C-dots fractions can be used as fluorescent probes for sensitive detection of Fe3+ and Hg2+.

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