scholarly journals The Facile Synthesis of Novel ZnO Nanostructure for Galactose Biosensor Application

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Phuong Ha La Phan ◽  
Quang Trung Tran ◽  
Duc Anh Dinh ◽  
Ko Kang Bok ◽  
Chang-Hee Hong ◽  
...  

We introduce a novel structure of ZnO nanorods (NRs) grown on ZnO NRs (ZnO NRs/NRs) via a facile, low-cost, and environmentally friendly synthesis for galactose biosensor application. The galactose oxidase enzyme (GalOx) is immobilized on the ZnO NR/NR surface to form the novel electrode structure (GalOx|ZnO NRs/NRs). The GalOx|ZnO NR/NR electrode has a linear detection range of current density from 11.30 μA/mm2 to 18.16 μA/mm2 over a galactose concentration range from 40 mM to 230 mM, indicating the increment of electrode sensitivity up to 60.7%. The ZnO NR/NR morphology with a high surface area to volume ratio has a great contribution to the electrochemical performance of galactose biosensor. Our results propose a straightforward approach to fabricate architecturally ZnO-based nanostructure for biosensor application.

2017 ◽  
Vol 1 (T4) ◽  
pp. 123-129
Author(s):  
Ha Phan Phuong La ◽  
Hien Thi Thu Nguyen ◽  
Trung Quang Tran

ZnO nanomaterial is a n-type semiconductor material and exits in a variety of one-dimensional nanostructures such as: nanorods, nanotubes, nanowalls, nanowires, ect… [3]. They have potential applications in making devices such as: light emiting diodes, optical waveguides, nanolaser, gas sensor, biosensor. Due to the high surface area to volume ratios, nontoxicity, chemical stability, biocompatibility, the high isoelectric point (IEP: 9.5), ect…; ZnO nanorods were largely used for biosensor. In this work, we developed enzyme electrode biosensor based on ZnO nanorods to test galactose solution by immobilizing galactose oxidase on ZnO nanorods grown on FTO substrate. The result showed that the proposed biosensor had the linear detection range from 40 to 230 mM galactose solution.


Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 9
Author(s):  
M. Olga Guerrero-Pérez

During the last two decades, electrospinning has become a very popular technique for the fabrication of nanofibers due to its low cost and simple handling. Nanofiber materials have found utilization in many areas such as medicine, sensors, batteries, etc. In catalysis, these materials also present important advantages, since they present a low resistance to internal diffusion and a high surface area to volume ratio. These advantages are mainly due to the diameter–length proportion. A bibliographic analysis on the applications of electrospun nanofibers in catalysis shows that there are two important groups of catalysts that are being investigated, based on TiO2 and in carbon materials. The main applications found are in photo- and in electro-catalysis. The present study contributes by reviewing these catalytic applications of electrospun nanofibers and demonstrating that they are promising materials as catalysts, underlining some works to prove the advantages and possibilities that these materials have as catalysts. On one hand, the possibilities of synthesis are almost infinite, since with coaxial electrospinning quite complex nanofibers with different layers can be prepared. On the other hand, the diameter and other properties can be controlled by monitoring the applied voltage and other parameters during the synthesis, being quite reproducible procedures. The main advantages of these materials can be grouped in two: one related to their morphology, as has been commented, relative to their low resistance and internal diffusion, that is, their fluidynamic behavior in the reactor; the second group involves advantages related to the fact that the active phases can be nanoscaled and dispersed, improving the activity and selectivity in comparison with conventional catalytic materials with the same chemical composition.


2021 ◽  
Author(s):  
Ashoka Gamage ◽  
Thiviya Punniamoorthy ◽  
Terrence Madhujith

Environmental pollution is becoming a major global issue with increasing anthropogenic activities that release massive toxic pollutants into the land, air, and water. Nanomaterials have gained the most popularity in the last decades over conventional methods because of their high surface area to volume ratio and higher reactivity. Nanomaterials including metal, metal oxide, zero-valent ions, carbonaceous nanomaterials, and polymers function as adsorbents, catalysts, photocatalysts, membrane (filtration), disinfectants, and sensors in the detection and removal of various pollutants such as heavy metals, organic pollutants, dyes, industrial effluents, and pathogenic microbial. Polymer-inorganic hybrid materials or nanocomposites are highly studied for the removal of various contaminants. Starch, a heteropolysaccharide, is a natural biopolymer generally incorporated with other metal, metal oxide, and other polymeric nanoparticles and has been reported in various environmental remediation applications as a low-cost alternative for petroleum-based polymers. Therefore, this chapter mainly highlights the various nanomaterials used in environmental remediation, starch-based hybrid nanomaterials, and their application and limitations.


Author(s):  
Ravindra Kumar Gautam ◽  
Shivani Soni ◽  
Mahesh Chandra Chattopadhyaya

Water pollution by anthropogenic activities is proving to be of critical concern as the heavy metals affect aquatic organisms and can quickly disperse to large distances. This poses a risk to both human health and the aquatic biota. Hence, there is a need to treat the wastewater containing toxic metals before they are discharged into the water bodies. During recent years, magnetic nanoparticles came to the foreground of scientific interest as a potential adsorbent of novel wastewater treatment processes. Magnetic nanoparticles have received much attention due to their unique properties, such as extremely small size, high surface-area-to-volume ratio, surface modifiability, multi functionality, excellent magnetic properties, low-cost synthesis, and great biocompatibility. The multi-functional magnetic nanoparticles have been successfully applied for the reduction of toxic metal ions up to ppb level in waste-treated water. This chapter highlights the potential application of magnetic nanoparticles for the removal of heavy metals.


Author(s):  
Ravindra Kumar Gautam ◽  
Shivani Soni ◽  
Mahesh Chandra Chattopadhyaya

Water pollution by anthropogenic activities is proving to be of critical concern as the heavy metals affect aquatic organisms and can quickly disperse to large distances. This poses a risk to both human health and the aquatic biota. Hence, there is a need to treat the wastewater containing toxic metals before they are discharged into the water bodies. During recent years, magnetic nanoparticles came to the foreground of scientific interest as a potential adsorbent of novel wastewater treatment processes. Magnetic nanoparticles have received much attention due to their unique properties, such as extremely small size, high surface-area-to-volume ratio, surface modifiability, multi functionality, excellent magnetic properties, low-cost synthesis, and great biocompatibility. The multi-functional magnetic nanoparticles have been successfully applied for the reduction of toxic metal ions up to ppb level in waste-treated water. This chapter highlights the potential application of magnetic nanoparticles for the removal of heavy metals.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. E. A. Botteon ◽  
L. B. Silva ◽  
G. V. Ccana-Ccapatinta ◽  
T. S. Silva ◽  
S. R. Ambrosio ◽  
...  

AbstractGold nanoparticles (AuNPs) are highlighted due to their low toxicity, compatibility with the human body, high surface area to volume ratio, and surfaces that can be easily modified with ligands. Biosynthesis of AuNPs using plant extract is considered a simple, low-cost, and eco-friendly approach. Brazilian Red Propolis (BRP), a product of bees, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. Here, we described the biosynthesis of AuNPs using BRP extract (AuNPextract) and its fractions (AuNPhexane, AuNPdichloromethane, AuNPethyl acetate) and evaluated their structural properties and their potential against microorganisms and cancer cells. AuNPs showed a surface plasmon resonance (SPR) band at 535 nm. The sizes and morphologies were influenced by the BRP sample used in the reaction. FTIR and TGA revealed the involvement of bioactive compounds from BRP extract or its fractions in the synthesis and stabilization of AuNPs. AuNPdichloromethane and AuNPhexane exhibited antimicrobial activities against all strains tested, showing their efficacy as antimicrobial agents to treat infectious diseases. AuNPs showed dose-dependent cytotoxic activity both in T24 and PC-3 cells. AuNPdichloromethane and AuNPextract exhibited the highest in vitro cytotoxic effect. Also, the cytotoxicity of biogenic nanoparticles was induced by mechanisms associated with apoptosis. The results highlight a potential low-cost green method using Brazilian red propolis to synthesize AuNPs, which demonstrated significant biological properties.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 838 ◽  
Author(s):  
Jiushuai Xu ◽  
Maik Bertke ◽  
Xuejing Li ◽  
Andi Setiono ◽  
Michael Fahrbach ◽  
...  

This paper reports a piezoresistive silicon microcantilever-based gravimetric humidity sensor, where a ZnO nanofilm (200 nm) and ZnO nanorods (NRs) with different lengths (1.5 µm and 6 µm) modified with chitosan self-assembled monolayers (SAMs) are coated on the microcantilevers’ back surface as the sensing material. Thanks to the new sensor design, the resonant frequency (RF) shifts induced by the mass adsorption on the high surface-area-to-volume ratio, hybrid-sensing nanostructure can be tracked directly by monitoring the output of the p-diffused full Wheatstone bridge. By depositing ZnO NRs and Chitosan SAMs, direct-reading microcantilevers with high repeatability, reliability and high sensitivity (15 Hz/%RH) can be achieved.


Química Nova ◽  
2021 ◽  
Author(s):  
Luiza Mercante ◽  
Rafaela Andre ◽  
Juliana Macedo ◽  
Adriana Pavinatto ◽  
Daniel Correa

ELECTROSPUN NANOFIBERS AND THEIR APPLICATIONS: ADVANCES IN THE LAST DECADE. In recent years there has been an increasing interest in the development of nanomaterials with improved properties compared to their counterparts at the micro- and macroscopic scale. In this context, nanofibers obtained by electrospinning technique are highly attractive due to the unique combination of high surface area/volume ratio, porosity, flexibility, mechanical performance, simple processing and relatively low cost. In addition, the possibility to buildup nanofibers with different compositions, structures and properties allows the design of nanostructures for a wide range of applications. In this review, we will discuss the advances of the last decade in the use of the electrospinning to obtain nanofibers with different compositions and morphologies for varied applications. Specifically, we are interested in providing an overview of the state of the art in relation to the application of nanofibers in different areas, including healthcare, environment, sensing and energy. Finally, we will discuss the real perspective in terms of industrial application and future trends that have been pursued to improve the performance of electrospun nanofibers. This review will help researchers to understand the evolution and challenges of the area and will also stimulate even more interest in the development of new devices based on electrospun nanofibers


RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20601-20611
Author(s):  
Md. Mijanur Rahman ◽  
Kenta Inaba ◽  
Garavdorj Batnyagt ◽  
Masato Saikawa ◽  
Yoshiki Kato ◽  
...  

Herein, we demonstrated that carbon-supported platinum (Pt/C) is a low-cost and high-performance electrocatalyst for polymer electrolyte fuel cells (PEFCs).


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 657
Author(s):  
Geul Han Kim ◽  
Yoo Sei Park ◽  
Juchan Yang ◽  
Myeong Je Jang ◽  
Jaehoon Jeong ◽  
...  

Developing high performance, highly stable, and low-cost electrodes for the oxygen evolution reaction (OER) is challenging in water electrolysis technology. However, Ir- and Ru-based OER catalysts with high OER efficiency are difficult to commercialize as precious metal-based catalysts. Therefore, the study of OER catalysts, which are replaced by non-precious metals and have high activity and stability, are necessary. In this study, a copper–cobalt oxide nanosheet (CCO) electrode was synthesized by the electrodeposition of copper–cobalt hydroxide (CCOH) on Ni foam followed by annealing. The CCOH was annealed at various temperatures, and the structure changed to that of CCO at temperatures above 250 °C. In addition, it was observed that the nanosheets agglomerated when annealed at 300 °C. The CCO electrode annealed at 250 °C had a high surface area and efficient electron conduction pathways as a result of the direct growth on the Ni foam. Thus, the prepared CCO electrode exhibited enhanced OER activity (1.6 V at 261 mA/cm2) compared to those of CCOH (1.6 V at 144 mA/cm2), Co3O4 (1.6 V at 39 mA/cm2), and commercial IrO2 (1.6 V at 14 mA/cm2) electrodes. The optimized catalyst also showed high activity and stability under high pH conditions, demonstrating its potential as a low cost, highly efficient OER electrode material.


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