scholarly journals Graphene Oxide-Based Nanohybrids as Pesticide Biosensors: Latest Developments

Author(s):  
Navin Kumar Mogha

Graphene is the most significant two-dimensional nanomaterial with sp2 hybridized carbon atoms in a honeycomb arrangement with an extremely high surface area, excellent electrical properties, high mechanical strength, and advantageous optical properties and is relatively easy to functionalize and mass produce. Various inorganic nanoparticles incorporated with graphene, such as gold, silver, and palladium nanoparticles are brought into sharp focus due to their catalytic, optical, electronic, and quantized charging/discharging properties. Graphene oxide-based nanohybrids are particularly well suited for biosensing applications and catalysis. Consequently, this area of research has grown to represent one of the largest classes within the scope of materials science and is rapidly becoming a key area in nanoscience and nanotechnology offering significant potential in the development of advanced materials in multiple and diverse applications. Here in this present chapter, synthesis, characterization of graphene oxide, and their nanohybrids are discussed thoroughly with their application in the field of pesticide biosensors. This chapter will help in a further understanding of graphene-based nanohybrids as a biosensing platform for their future applications in a sustainable environment.


Author(s):  
Soumitra Satapathi ◽  
Rutusmita Mishra ◽  
Manisha Chatterjee ◽  
Partha Roy ◽  
Somesh Mohapatra

Nano-materials based drug delivery modalities to specific organs and tissues has become one of the critical endeavors in pharmaceutical research. Recently, two-dimensional graphene has elicited considerable research interest because of its potential application in drug delivery systems. Here we report, the drug delivery applications of PEGylated nano-graphene oxide (nGO-PEG), complexed with a multiphoton active and anti-cancerous diarylheptanoid drug curcumin. Specifically, graphene-derivatives were used as nanovectors for the delivery of the hydrophobic anticancer drug curcumin due to its high surface area and easy surface functionalization. nGO was synthesized by modified Hummer’s method and confirmed by XRD analysis. The formation of nGO, nGO-PEG and nGO-PEG-Curcumin complex were monitored through UV-vis, IR spectroscopy. MTT assay and AO/EB staining found that nGO-PEG-Curcumin complex afforded highly potent cancer cell killing in vitro with a human breast cancer cell line MCF7.



2017 ◽  
Vol 75 (10) ◽  
pp. 2403-2411 ◽  
Author(s):  
Zongxue Yu ◽  
Qi Chen ◽  
Liang Lv ◽  
Yang Pan ◽  
Guangyong Zeng ◽  
...  

The environmental applications of graphene oxide and β-cyclodextrin (β-CD) have attracted great attention since their first discovery. Novel nanocomposites were successfully prepared by using an esterification reaction between β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane grafted graphene oxide (β-CD/GPTMS/GO). The β-CD/GPTMS/GO nanocomposites were used to remove the Cu2+ from aqueous solutions. The characteristics of β-CD/GPTMS/GO were detected by scanning electron microscopy (SEM), Fourier transform infrared, X-ray diffraction (XRD), thermogravimetric analysis (TG) and energy dispersive X-ray (EDX). The dispersibility of graphene oxide was excellent due to the addition of β-CD. The adsorption isotherms data obtained at the optimum pH 7 were fitted by Langmuir isotherm model. The excellent adsorption properties of β-CD/GPTMS/GO for Cu2+ ions could be attributed to the apolar cavity structure of β-CD, the high surface area and abundant functional groups on the surface of GO. The adsorption patterns of β-CD/GPTMS/GO were electrostatic attraction, formation of host-guest inclusion complexes and the ion exchange adsorption. The efficient adsorption of β-CD/GPTMS/GO for Cu2+ ions suggested that these novel nanocomposites may be ideal candidates for removing other cation pollutants from waste water.



2019 ◽  
Vol 16 (32) ◽  
pp. 279-286
Author(s):  
Marcos Antônio KLUNK ◽  
Zeban SHAH ◽  
Paulo Roberto WANDER

Removal of malachite green dye by adsorption from aqueous solution using montmorillonite clay is reported in this work. A malachite green dye is a cationic widely used in textile industries. Due to its persistence in the aquatic environment, it becomes a problem for aquatic and terrestrial organisms. This dye can be adsorbed through various techniques, but high acquisition and operating costs preclude widespread use. Several adsorbents are available in the market, but the most outstanding are the clays, especially the montmorillonites. These clays are finely divided material ( 0.002 mm), and its adsorption properties are continuously investigated. Types of clays 2:1 (two tetrahedral to one octahedral) are called expandables. The montmorillonite has a potential for dyes removal in wastewater due to the high surface area, porosity with excellent cation exchange capacity conferring its adsorbent property. This work aims to use the montmorillonite as an adsorption system in stages to textile decolorization effluent, composed of malachite green dye, reproduced in the laboratory. The characterization of the clay gives high purity and is used as adsorbent of good quality and efficiency. The retention of dyes in the system composed of montmorillonite arranged in separation stages was efficient. The effect of dye concentration and retention time are the most important parameters used in this study. High concentrations and retention time below 24 hours resulted in low levels of removal (25%). On the other hand, the low level of initial concentration increases removal efficiency (57%). Thus, the results obtained in this work allow concluding that montmorillonite is able to removal malachite green dye.



2017 ◽  
Vol 36 (3) ◽  
pp. 44-53
Author(s):  
G. D. Akpen ◽  
M. I. Aho ◽  
N. Baba

Activated carbon was prepared from the pods of Albizia saman for the purpose of converting the waste to wealth. The pods were thoroughly washed with water to remove any dirt, air- dried and cut into sizes of 2-4 cm. The prepared pods were then carbonised in a muffle furnace at temperatures of 4000C, 5000C, 6000C ,7000C and 8000C for 30 minutes. The same procedure was repeated for 60, 90, 120 and 150 minutes respectively. Activation was done using impregnationratios of 1:12, 1:6, 1:4, 1:3, and 1:2 respectively of ZnCl2 to carbonised Albizia saman pods by weight. The activated carbon was then dried in an oven at 1050C before crushing for sieve analysis. The following properties of the produced Albizia saman pod activated carbon (ASPAC) were determined: bulk density, carbon yield, surface area and ash, volatile matter and moisture contents. The highest surface area of 1479.29 m2/g was obtained at the optimum impregnation ratio, carbonization time and temperature of 1:6, 60 minutes and 5000C respectively. It was recommended that activated carbon should be prepared from Albizia saman pod with high potential for adsorption of pollutants given the high surface area obtained.Keywords: Albizia saman pod, activated carbon, carbonization, temperature, surface area



1996 ◽  
Vol 457 ◽  
Author(s):  
Lin-chiuan Yan ◽  
Levi T. Thompson

ABSTRACTNew methods have been developed for the synthesis of high surface area cation-substituted hexaaluminates. These materials were prepared by calcining high temperature (ethanol extraction) or low temperature (CO2 extraction) aerogels at temperatures up to 1600°C. Cation-substituted hexaaluminates have emerged as promising catalysts for use in high temperature catalytic combustion. In comparing unsubstituted and cation-substituted hexaaluminates, we found that the phase transformations were much cleaner for the cation-substituted materials. BaCO3 and BaAl2O4 were intermediates during transformation of the unsubstituted materials, while the cation-substituted materials transformed directly from an amorphous phase to crystalline hexaaluminate. Moreover, the presence of substitution cations caused the transformation to occur at lower temperatures. Mn seems to be a better substitution cation than Co since the Mn-substituted materials exhibited higher surface areas and better heat resistances than the Co-substituted materials. The low temperature aerogel-derived materials possessed quite different characteristics from the high temperature aerogel-derived materials. For example, phase transformation pathways were different.





1999 ◽  
Vol 179 (1-2) ◽  
pp. 203-216 ◽  
Author(s):  
Eiji Hayashi ◽  
Eiji Iwamatsu ◽  
Mohammad Elias Biswas ◽  
Yuzo Sanada ◽  
Shakeel Ahmed ◽  
...  


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