Eco-friendly Nanomaterials Research Articles

Effective Bio-mediated Nanoparticles for Bioremediation of Toxic Metal Ions from Wastewater – A Review

Water tainted with colours, heavy metal ions and biological toxins, contributes to eutrophication, which in turn contributes to a variety of fatal diseases in humans and other animals, owing to the fact that water purification equipment and methods are not cheap. Due to this, there is a pressing need for economically viable wastewater treatment components. Eco-friendly nanomaterials, highly efficient and selective, renewable, earth-abundant and stable, have emerged as a major priority, overcoming a number of challenges and restrictions. Currently, the combination of nanomaterials and biomolecules from plants, including polyphenols, amines and other components, as well as intracellular and extracellular enzymes found in microbes, has become more significant in bioremediation. Biogenic nanoparticles are favoured because they are easy to expand for large-scale biosynthesis, maintain stability for an extended period, consume less time, are eco-friendly, and do not produce any detrimental by-products. The processes of nano-bioremediation and wastewater treatment are discussed in detail in this review. It primarily focuses on synthesizing, characterizing and applying bio-mediated nanoparticles, which actively remove heavy metal ions from wastewater, without adversely affecting individuals or other living things, especially in aquatic environments.

Evaluation of Eco-Friendly Nanomaterial Modified Water-Based Varnish Systems

Evaluation of Eco-Friendly Nanomaterial Modified Water-Based Varnish Systems

Algae-based green AgNPs, AuNPs, and FeNPs as potential nanoremediators

Abstract This review addresses green algae-based gold (Au), iron (Fe), and silver (Ag) nanoparticles (NPs) as eco-friendly nanomaterials to deal with biological, organic, and inorganic environmental contaminants. Among nanotechnological tools that can fully degrade, adsorb, and/or convert pollutants into less harmful structures, AgNPs, AuNPs, and FeNPs deserve highlight for their efficiency and low cost. However, green protocols are preferable to produce them in an eco-friendly manner. Although phycosynthesis is still in its infancy, algae present various advantages as green raw materials to NPs’ synthesis; fast growth rate, low-energy input requirement, low costs, easy and eco-friendly cultivation, and high tolerance to metals are examples. To allow their large-scale application, however, challenges regarding obtaining sufficient biomaterial with good reproducibility, designing protocols to achieve desirable features on NPs, and recovering the biocompatible nanomaterial after use still need attention. Perspectives for the field involve surpassing these limitations, broadening knowledge on synthesis mechanisms, protocols, and new species useful to offer, in the future, commercial eco-friendly, and low-cost phycosynthesized AuNPs, AgNPs, and FeNPs to nanoremediation. The potential of these NPs to deal with environmental contaminants, their advantageous characteristics and biocompatibility, the main limitations associated with their large-scale application, and future prospects for the field will receive attention.

Biogeneration of Valuable Nanomaterials from Agro-Wastes: A Comprehensive Review

The exponential growth of agricultural output is a result of the increasing world population. Agro-wastes are now acknowledged as an alternative material for the manufacture of renewable, inexpensive, and sustainable bio-composite-based products. Huge amounts of agricultural produce are often lost owing to a lack of processing facilities or storage space. Agriculture wastes contain a significant concentration of carbohydrates as well as various multifunctional groups and organic substances, such as polymeric proteins. Interestingly, nanotechnology provides better potential to transform agricultural wastes easily into valuable and cost-effective products, removing the need to utilize noxious chemicals, which can create a variety of health and environmental difficulties. Recently, there has been an increase in interest in eco-friendly nanomaterial (NM) production techniques that utilize extracts generated from agricultural waste. Such nanoparticles (NPs) have been extensively studied for numerous uses, including antibacterial agents, water purification, the breakdown of industrial colours, and many others. Consequently, the purpose of this review is to investigate the different sources, characteristics, and nano-management of agro-waste; valuable NMs derived from agro-waste; and their possible applications.

Picomolar Detection of Lead Ions (Pb2+) by Functionally Modified Fluorescent Carbon Quantum Dots from Watermelon Juice and Their Imaging in Cancer Cells.

Water contamination due to the presence of lead is one of the leading causes of environmental and health hazards because of poor soil and groundwater waste management. Herein we report the synthesis of functionally modified luminescent carbon quantum dots (CQDs) obtained from watermelon juice as potential nanomaterials for the detection of toxic Pb2+ ions in polluted water and cancer cells. By introducing surface passivating ligands such as ethanolamine (EA) and ethylenediamine (ED) in watermelon juice, watermelon-ethanolamine (WMEA)-CQDs and watermelon-ethylenediamine (WMED)-CQDs exhibited a remarkable ~10-fold and ~6-fold increase in fluorescence intensity with respect to non-doped WM-CQDs. The relative fluorescence quantum yields of WMEA-CQDs and WMED-CQDs were found to be 8% and 7%, respectively, in an aqueous medium. Among various functionally-modified CQDs, only WMED-CQDs showed high selectivity towards Pb2+ ions with a remarkably good limit of detection (LoD) of 190 pM, which is less than that of the permissible limit (72 nM) in drinking water. The functionally altered WMED-CQDs detected Pb2+ metal ions in polluted water and in a human cervical cancer cell line (HeLa), thus advocating new vistas for eco-friendly nanomaterials for their use as diagnostic tools in the environment and biomedical research areas.

Experimental and modeling study of laser induced silicon carbide/graphene on cotton cloth for superhydrophobic applications

Laser-induced graphene (LIG) from natural resources is a green, low-cost and eco-friendly nanomaterial, but its application is limited by the single-scale structure and inherent rigidity. In this work, cotton cloth is pre-carbonized and then embedded in polydimethylsiloxane (PDMS) elastomer to prepare silicon carbide/LIG (SiC/LIG) hybrids by laser scribing. The horizontal and vertical heat transfer in the carbonized cloth (CC) fiber network is distinguished by a self-established heat conduction theory and verified by a finite element analysis (FEA) model. The SiC/LIG nanosheets are distributed around CC fibers to form a core–shell structure, whose morphology and composition are adjusted by the laser fluence. The outer shell of SiC/LIG provides low surface energy and high specific surface area, while the inner core of CC ensures stable mechanical properties. The core–shell structure of SiC/LIG is coupled with the network structure of CC to form a three-dimensional (3D) hierarchical electrode with a water contact angle of 152.4° ± 2.5° and a water slide angle of 7.7° ± 2.5°. Following the “lotus effect”, the SiC/LIG electrode exhibits broad prospects in wearable electronics with static/dynamic superhydrophobicity, multiple contact-rebound behaviors, temperature/time wetting stability and self-cleaning properties.

Micelle-mediated assembly of metals in Ag@MnOx/m-SiO2 for reinforced antimicrobial activity and photothermal water evaporation

The increasing complexity of environmental pollution posed a higher requirement for the development of environment-governed functional materials. Herein, to achieve desired synergy and multiple functionalities of eco-friendly nanomaterials, a micelle-mediated metal assembly strategy was proposed to integrate plasmonic Ag nanoparticles into MnOx modified mesoporous silica hosts by metal-modified neutral dodecyl amine surfactant, correspondingly, a multifunctional mesoporous Ag@MnOx/m-SiO2 (AMSs) nanocomposite was obtained. The characterization results revealed that the introduction of Mn and alteration in the amount of Ag mediated the formation of a special mesostructure and nanometric morphology of the silica host. Bearing a low Ag loading (r.t. of Ag/Mn = 1/2), ultrafine Ag nanoparticles were embedded in the inner core of mesoporous silica nanospheres. While assembly with a higher Ag concentration affected the morphology of the obtained AMSs and resulted in rich Ag nanoparticles on the exterior surface of mesoporous silica. By this strategy, ultrafine Ag nanoparticles and well-dispersed amorphous MnOx species were coupled into the mesoporous silica to reach a special configuration and integrated functionality. The obtained AMSs-3 can effectively inactivate bacteria (E. coli, S. aureus, and P. aeruginosa) with a prolonged inhibitory effect, rapidly reduce harmful nitrophenol, as well as photothermally assist water evaporation (evaporation rate of 1.51 kg m−2 h−1, receiver efficiency of 87%). This work provides versatile environment-governing functional nanomaterials for both highly effective antimicrobial and environmental remediation.

Bioinspired Advances in Nanomaterials for Sustainable Agriculture

Rising demand for food production and an intensified usage of hazardous substances on the farmland are the driving force behind the emergence of green nanotechnology. Eco‐friendly nanomaterials synthesised using plant sources and microorganisms are expected to catalyse a revolution in the agricultural sector by introducing nano‐enabled smart sensors for metals along with organic toxins, supplying micronutrients; balancing the plant hormones, soil quality, and moisture content; stimulating plant growth; and minimising the usage of toxic chemicals by nanofertilizers and nanopesticides. As no single nanocompound has proved to be completely sustainable, this review discusses a wide variety of sustainable routes to implement nanomaterials to increase productivity, protect, and monitor crops through innovative nano‐aided agricultural practices. Nevertheless, as the progress of research and commercialization in this area is still marginal, an understanding of complex dynamic behaviour, careful evaluation with targeted delivery of these compounds in the environment, and strong governmental regulatory norms are necessary to realize the effectiveness of green nanotechnology for sustainable agriculture. This article outlines some major advancements in recent years related to the implementation of eco‐friendly nanomaterials in the agricultural sector. A systematic and comprehensive approach to adopting green nanotechnology would certainly promote a sustainable movement resulting in a beneficial economic and ecological impact.

Green synthesis of nanomaterials from sustainable materials for biosensors and drug delivery

The integration of biosensing platforms with drug delivery systems has led to effective treatment strategies for biomedical applications. With the emergency of nanotechnology, the manipulation of materials in the nanometer (nm) scale of 1–100 ​nm, these biosensing and drug delivery systems have been tremendously improved due to the exceptional properties exhibited by these materials. The conventional approaches used to synthesize the nanomaterials including physical and chemical methods involve the usage of harsh chemicals and hazardous reaction conditions hence posing a threat to health and the environment. This problem is solved by the biological methods that involve green nanotechnology which integrates green chemistry and engineering principles to formulate harmless and eco-friendly nanomaterials to fight the complications affecting human health and the environment. These biological methods use phytochemicals found in plants and plants parts as well as microorganisms for the bioreduction of metal ions to their corresponding nanomaterials. The plants and the microorganisms are readily available, cost-efficient, and have biocompatibility hence offering sustainable synthetic methods for nanomaterials. This review will therefore focus on the plant-mediated and microbe-mediated green synthesis of different nanomaterials, the mechanisms of these synthetic methods, the application of the green synthesized nanomaterials in biosensing and drug delivery as well as the challenges of the synthetic methods.

Phosphorescent Carbon-Nanodots-Assisted Förster Resonant Energy Transfer for Achieving Red Afterglow in an Aqueous Solution.

Water-soluble red afterglow imaging agents based on ecofriendly nanomaterials have potential application in time-gated afterglow bioimaging due to their larger penetration depth and nondurable excitation. Herein, red afterglow imaging agents consisted of Rhodamine B (RhB) and carbon nanodots (CNDs) have been designed and demonstrated. In these agents, CNDs act as energy donors, and RhB acts as an energy acceptor. Both of them are confined into a hydrophilic silica shell to form a CNDs-RhB@silica nanocomposite. The phosphorescence emission spectrum of the CNDs and the absorption spectrum of the RhB match well, and efficient energy transfer from the CNDs to the RhB via Förster resonant energy transfer process can be achieved, with a transfer efficiency can reach 99.2%. Thus, the as-prepared nanocomposite can emit a red afterglow in aqueous solution, and the afterglow spectrum of CNDs-RhB@silica nanocomposite can extend to the first near-infrared window (NIR-I). The luminescence lifetime and afterglow quantum yield (QY) of the CNDs-RhB@silica can reach 0.91 s and 3.56%, respectively, which are the best results in red afterglow region. Time-gated in vivo afterglow imaging has been demonstrated by using the CNDs-RhB@silica as afterglow agents.

Green Nanocomposites for Energy Storage

The green nanocomposites have elite features of sustainable polymers and eco-friendly nanofillers. The green or eco-friendly nanomaterials are low cost, lightweight, eco-friendly, and highly competent for the range of energy applications. This article initially expresses the notions of eco-polymers, eco-nanofillers, and green nanocomposites. Afterward, the energy-related applications of the green nanocomposites have been specified. The green nanocomposites have been used in various energy devices such as solar cells, batteries, light-emitting diodes, etc. The main focus of this artifact is the energy storage application of green nanocomposites. The capacitors have been recognized as corporate devices for energy storage, particularly electrical energy. In this regard, high-performance supercapacitors have been proposed based on sustainable nanocomposites. Consequently, this article presents various approaches providing key knowledge for the design and development of multi-functional energy storage materials. In addition, the future prospects of the green nanocomposites towards energy storage have been discussed.

Efficacy of Zinc Oxide Nanoparticle Adding to Two Neonicotinoids Pesticides against Spodoptera litura (Lepidoptera: Noctuidae) and Aphis gossypii Glover

In recent years, pesticide residues have become a danger to the food chain, the environment, and human health. Some nano metal oxides had been applied with pesticides to solve these problems and enhanced their insecticidal Activity. This new technology for the complete mineralization of pesticides is necessary to convert them to non-toxic forms. In this study, we investigated the synergistic effect of ZnO nanoparticles (NPs) with some neonicotinoid pesticides (Thioxam 25%WG and Actara 25% WP) against 4th instar larvae of Spodoptera litura (Lepidoptera: Noctuidae) and cotton aphid, Aphisgossypii Glover (Homoptera: Aphididea). These cotton pests were allowed to feed on castor leaves after impregnated with pesticides at recommended rate with the composite of ZnO (NPs). Observations showed an increase in mortality (48.57 %, 93.51 % increased mortality). The addition of the ZnO nanoparticles to insecticides increased the insecticidal activities and a reduction (%) against tested cotton pests. The synthesized nano metal oxide was characterized by different techniques as FTIR spectroscopy, TEM and UV spectroscopy used for a determination band gap of the prepared ZnO NPs. This present study suggests that nanoparticles metal oxide as (ZnO) applying as eco-friendly nanomaterial in the field of pest control.

Role of reinforcement on mechanical and thermal characteristics of polymer nano composites: A review

Polymers, especially thermoplastics, have high growth in the industry and manufacturing purposes. Acrylonitrile-Butadiene-Styrene (ABS) has properties like processability, rubber content, while Polycarbonate (PC) has the properties of high impact strength and toughness. So, blending these two thermoplastics will give the higher beneficial blend at cheaper costs which are used in various applications. Halloysite Nanotubes (HNT) are naturally occurring eco-friendly nanomaterials and possess better mechanical and thermal properties. Furthermore, these HNT’s are basically aluminosilicate clay materials for which Al2Si2O5(OH)4 is given as the empirical formula. The present review paper provides more insight into the latest trends in the preparation and characterization of polymer composites. Further, the latest works associated with the mechanical and thermal characterization of ABS/PC and HNT composites were critically reviewed.

Microbial Nanotechnology for Bioremediation of Industrial Wastewater.

Pollutant removal from industrial effluents is a big challenge for industries. These pollutants pose a great risk to the environment. Nanotechnology can reduce the expenditure made by industries to mitigate these pollutants through the production of eco-friendly nanomaterials. Nanomaterials are gaining attention due to their enhanced physical, chemical, and mechanical properties. Using microorganisms in the production of nanoparticles provides an even greater boost to green biotechnology as an emerging field of nanotechnology for sustainable production and cost reduction. In this mini review, efforts are made to discuss the various aspects of industrial effluent bioremediation through microbial nanotechnology integration. The use of enzymes with nanotechnology has produced higher activity and reusability of enzymes. This mini review also provides an insight into the advantages of the use of nanotechnology as compared to conventional practices in these areas.

Nano-enabled agriculture: from nanoparticles to smart nanodelivery systems

Environmental contextNano-enabled agriculture holds the promise of enhancing crop production while reducing the environmental impacts of agrochemicals. We review recent developments in the use of nano-fertilisers, nano-additives, nano-pesticides, nano-sensors, nano-cleansers and nano-delivery systems in agriculture. The review highlights the need for systematic studies on nanotoxicity and the development of cost-effective and eco-friendly nanomaterials for future applications. AbstractTo keep pace with the ever-increasing demand of world population (nearly 9.8 billion), worldwide food production will need to increase by 50% by 2050. Nanotechnology innovations show great promise for combating this challenge by delivering a more sustainable, efficient and resilient agricultural system, while promoting food security. Further exploration of nanotechnology applications in agriculture is necessary to realise its potential in manufacturing innovative agrochemicals and novel delivery platforms to enhance crop production and quality. Here, we review the fundamentals of nanotechnology and focus on its potential in agricultural applications. Progress has been made in the development of nano-fertilisers, nano-additives, nano-pesticides, nano-herbicides, nano-bactericides, nano-cleansers and nano-sensors to improve agrochemical efficiency, reduce runoff, enhance plant growth, and diagnose plant nutrition deficiencies and diseases. In addition, nano-delivery systems have been designed to deliver effective components to targeted sites within a plant to provide potential solutions to some devastating crop diseases which cannot be effectively managed with conventional methods. However, nano-enabled agriculture is still in its infancy and its applications are mostly theoretical. Therefore, more research is needed to develop biodegradable, cost-effective and safe nanomaterials for future application. Moreover, systematic studies are crucial to safeguard our food production system, while making efforts to raise public awareness of nanotechnology.

Gold nanoparticles synthesized from Euphorbia fischeriana root by green route method alleviates the isoprenaline hydrochloride induced myocardial infarction in rats

The procurance of gold nanoparticles in the plant extracts is an excellent way to attain nanomaterials natural and eco-friendly nanomaterials. The Dehydrated roots of Chinese Euphorbia fischeriana flowering plant are called “Lang-Du”. In this study, the retrieving of gold nanoparticles from Euphorbia fischeriana root was amalgamated by standard procedure. Fabricated gold nanoparticles were portrayed through the investigations of ultraviolet and visible spectrophotometry (UV–Vis), Fourier transform infrared spectroscopy (FTIR), High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The UV–Vis and FTIR results explicated the obtained particles were sphere-shaped and the terpenoids of Euphorbia fischeriana had strong communications with gold surface. The HRTEM and XRD images exposed the produced gold nanoparticles had an extreme composition of crystal arrangement and excellent uniformed size of particles. In our study, the Isoprenaline induced myocardial damage established the elevation in TBARS, LOOH of heart tissues and notable decline in antioxidant enzymes SOD, CAT, GPx, and GSH. This biochemical result was additionally proved by histopathological assessment. Remarkably, the pretreatment with EF-AuNps(50 mg/kg b.w) illustrated stabilized levels of serum creatine and cardiotropins in myocardial infarcted animals. And further we understood the essential function of NF-ƙB, TNF-α, IL-6 signaling molecules and its way progression in the development of vascular tenderness.

Biocompatible Fe3O4@SiO2-NH2 nanocomposite as a green nanofiller embedded in PES-nanofiltration membrane matrix for salts, heavy metal ion and dye removal: Long-term operation and reusability tests.

High purity amorphous silica (95.55%) was simply extracted from rice husk and used as a shell for Fe3O4 magnetic nanoparticles. The obtained eco-friendly nanomaterial was functionalized by (3-Aminopropyl)trimethoxysilane and characterized by SEM, FT-IR, XRD, VSM, TEM and zeta potential analyses. The synthesized Fe3O4@SiO2-NH2 nanocomposite was embedded into the polyethersulfone membranes with different concentrations via phase inversion method. The effects of Fe3O4@SiO2-NH2 on various properties of the prepared nanofiltration membranes including membrane morphology, hydrophilicity, porosity, and mechanical stability were investigated using SEM image, water contact angle test, porosity measurement and mechanical property analysis, respectively. The performance of Fe3O4@SiO2-NH2 nanocomposite modified membranes was evaluated by measuring the pure water flux, salts rejection, Cd(II) ions removal, MR dye retention, and antifouling property. The results showed that the pure water flux was significantly increased in Fe3O4@SiO2-NH2 modified membranes due to the presence of hydrophilic functional groups on the Fe3O4@SiO2-NH2 surface. In addition, the significant enhancement in efficiency of modified membranes for removal of Cd(II) ions and MR dye was observed due to the adsorption properties of Fe3O4@SiO2-NH2 nanocomposite. Among the modified membranes with different concentrations of Fe3O4@SiO2-NH2, the 0.5 wt% concentration of nanocomposite showed the highest efficiency for the removal of Cd(II) ions (93%) and MR dye (97%). Membrane reusability study indicated a slightly decrease (≈7%) in Cd(II) ions removal after five continuous cycles. Membrane long-term filtration study showed a little reduction in permeate flux with unchanged MR dye retention during long-term filtration, which confirmed the stability of modified membrane.

Antibacterial Silver Nanomaterial Synthesis From Mesoflavibacter zeaxanthinifaciens and Targeting Biofilm Formation.

Considering the significance of biological and eco-friendly nanomaterials, in the present study, we have synthesized silver nanoparticles from the exopolysaccharide of recently recovered bacterial strain CEES51 from the Red Sea coastal area of Jeddah, Saudi Arabia. 16S ribosomal RNA gene sequencing was used to characterize the isolated bacteria, and it was identified as Mesoflavibacter zeaxanthinifaciens and assigned an accession number MH707257.1 GenBank. The bacterial strain is an excellent exopolysaccharide producer and survived at hypersaline (30%) and high-temperature (50°C) conditions. The bacterial exopolysaccharides were employed for the fabrication of silver nanoparticles at room temperature. UV-visible spectrophotometer optimized the synthesized nanoparticles, and their size was determined by Nanophox particle size analyzer and dynamic light scattering. Additionally, the X-ray powder diffraction and Fourier-transform infrared spectroscopy studies also approved its crystalline nature and the involvement of organic functional groups in their formation. The synthesized nanomaterials were tested for their antibacterial and antibiofilm properties against pathogenic microorganisms Bacillus subtilis and methicillin-resistant Staphylococcus aureus. The antimicrobial property showed time, and dose-dependent response with a maximum of zone inhibition was observed at around 22 and 18 mm at a dose of 50 µg/well against B. subtilis and S. aureus and a minimum inhibitory concentration of 8 and 10 µg/ml, respectively. Furthermore, the synthesized silver nanoparticles possessed a substantial antibiofilm property and were also found to be biocompatible as depicted by red blood cell lysis assay and their interaction with peripheral blood mononuclear cells and human embryonic kidney 293 cells. Therefore, Mesoflavibacter zeaxanthinifaciens is found to be an excellent source for exopolysaccharide synthesis that assists in the silver nanoparticle production.

Improved response time of flexible microelectromechanical sensors employing eco-friendly nanomaterials.

Flexible force/pressure sensors are of interest for academia and industry and have applications in wearable technologies. Most of such sensors on the market or reported in journal publications are based on the operation mechanism of probing capacitance or resistance changes of the materials under pressure. Recently, we reported the microelectromechanical (MEM) sensors based on a different mechanism: mechanical switches. Multiples of such MEM sensors can be integrated to achieve the same function of regular force/pressure sensors while having the advantages of ease of fabrication and long-term stability in operation. Herein, we report the dramatically improved response time (more than one order of magnitude) of these MEM sensors by employing eco-friendly nanomaterials-cellulose nanocrystals. For instance, the incorporation of polydimethysiloxane filled with cellulose nanocrystals shortened the response time of MEM sensors from sub-seconds to several milliseconds, leading to the detection of both diastolic and systolic pressures in the radial arterial blood pressure measurement. Comprehensive mechanical and electrical characterization of the materials and the devices reveal that greatly enhanced storage modulus and loss modulus play key roles in this improved response time. The demonstrated fast-response flexible sensors enabled continuous monitoring of heart rate and complex cardiovascular signals using pressure sensors for future wearable sensing platforms.