Biological Synthesis of Nanocatalysts and Their Applications

Is the trend toward a sustainable green synthesis of copper oxide nanoparticles completely safe for Oreochromis niloticus when compared to chemical ones?: using oxidative stress, bioaccumulation, and histological biomarkers

Scientists worldwide have noticed that cutting-edge technologies can be used to produce nanoparticles (NPs) in a sustainable and environmentally friendly way, instead of the old methods. However, the effectiveness of this approach for aquatic environments and species still needs to be determined. Therefore, this study aims to compare between the toxicity of green and chemically synthesized copper oxide nanoparticles (GS and CS) CuO NPs at two different concentrations on Nile tilapia (Oreochromis niloticus) using various biomarkers. CuO NPs' formation was proved, and their different characterizations were recorded. Then, the fish samples were randomly allocated in glass aquaria into five groups: one acted as a control group, and the other groups were exposed to two concentrations (25 and 50 mg/L) of GS-CuO NPs and CS-CuO NPs, separately, for 4 days. After the experimental time, in all groups that were exposed to two concentrations of both synthesized CuO NPs, the results revealed that glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and thiobarbituric acid reactive substances (TBARS) levels were elevated in the liver and gills compared to glutathione reduced (GSH) content, which showed a significant decline. Bioaccumulation of Cu was more prevalent in the liver than in the gills, and the highest bioaccumulation capacity was more evident in the groups exposed to CS-CuO NPs. Moreover, the bioaccumulation of Cu caused severe histological changes in the liver and gills. In conclusion, the results suggested that GS-CuO NPs revealed less toxicity than CS-CuO NPs to the examined fish. However, they are still toxic, and their toxic effect cannot be overlooked.

From nature to nanotechnology: The interplay of traditional medicine, green chemistry, and biogenic metallic phytonanoparticles in modern healthcare innovation and sustainability

As we navigate the modern era, the intersection of time-honoured natural remedies and contemporary scientific approaches forms a burgeoning frontier in global healthcare. For generations, natural products have been foundational to health solutions, serving as the primary healthcare choice for 80% to 85% of the world's population. These herbal-based, nature-derived substances, significant across diverse geographies, necessitate a renewed emphasis on enhancing their quality, efficacy, and safety. In the current century, the advent of biogenic phytonanoparticles has emerged as an innovative therapeutic conduit, perfectly aligning with principles of environmental safety and scientific ingenuity. Utilizing green chemistry techniques, a spectrum of metallic nanoparticles including elements such as copper, silver, iron, zinc, and titanium oxide can be produced with attributes of non-toxicity, sustainability, and economic efficiency. Sophisticated herb-mediated processes yield an array of plant-originated nanomaterials, each demonstrating unique physical, chemical, and biological characteristics. These attributes herald new therapeutic potentials, encompassing antioxidants, anti-aging applications, and more. Modern technology further accelerates the synthesis of natural products within laboratory settings, providing an efficient alternative to conventional isolation methods. The collaboration between traditional wisdom and advanced methodologies now signals a new epoch in healthcare. Here, the augmentation of traditional medicine is realized through rigorous scientific examination. By intertwining ethical considerations, cutting-edge technology, and natural philosophy, the realms of biogenic phytonanoparticles and traditional medicine forge promising pathways for research, development, and healing. The narrative of this seamless integration marks an exciting evolution in healthcare, where the fusion of sustainability and innovation crafts a future filled with endless possibilities for human well-being. The research in the development of metallic nanoparticles is crucial for unlocking their potential in revolutionizing fields such as medicine, catalysis, and electronics, promising groundbreaking applications with enhanced efficiency and tailored functionalities in future technologies. This exploration is essential for harnessing the unique properties of metallic nanoparticles to address pressing challenges and advance innovations across diverse scientific and industrial domains.

A review on the green synthesis of nanoparticles, their biological applications, and photocatalytic efficiency against environmental toxins

Green synthesis of nanoparticles (NPs) using plant materials and microorganisms has evolved as a sustainable alternative to conventional techniques that rely on toxic chemicals. Recently, green-synthesized eco-friendly NPs have attracted interest for their potential use in various biological applications. Several studies have demonstrated that green-synthesized NPs are beneficial in multiple medicinal applications, including cancer treatment, targeted drug delivery, and wound healing. Additionally, due to their photodegradation activity, green-synthesized NPs are a promising tool in environmental remediation. Photodegradation is a process that uses light and a photocatalyst to turn a pollutant into a harmless product. Green NPs have been found efficient in degrading pollutants such as dyes, herbicides, and heavy metals. The use of microbes and flora in green synthesis technology for nanoparticle synthesis is biologically safe, cost-effective, and eco-friendly. Plants and microbes can now use and accumulate inorganic metallic ions in the environment. Various NPs have been synthesized via the bio-reduction of biological entities or their extracts. There are several biological and environmental uses for biologically synthesized metallic NPs, such as photocatalysis, adsorption, and water purification. Since the last decade, the green synthesis of NPs has gained significant interest in the scientific community. Therefore, there is a need for a review that serves as a one-stop resource that points to relevant and recent studies on the green synthesis of NPs and their biological and photocatalytic efficiency. This review focuses on the green fabrication of NPs utilizing diverse biological systems and their applications in biological and photodegradation processes.

Bio-Fabrication of Trimetallic Nanoparticles and Their Applications

Nanoparticles are materials whose size is less than 100 nm. Because of their distinctive physical and chemical characteristics, nanoparticles have drawn considerable interest in a variety of fields. Biosynthesis of nanoparticles is a green and environmentally friendly technology, which requires fewer chemical reagents, precursors, and catalysts. There are various types of nanomaterials, out of which trimetallic nanoparticles are receiving considerable interest in recent years. Trimetallic nanoparticles possess unique catalytic, biomedical, antimicrobial, active food packaging, and sensing applications as compared to monometallic or bimetallic nanoparticles. Trimetallic nanoparticles are currently synthesized by various methods such as chemical reduction, microwave-assisted, thermal, precipitation, and so on. However, most of these chemical and physical methods are expensive and toxic to the environment. Biological synthesis is one of the promising methods, which includes the use of bacteria, plants, fungi, algae, waste biomass, etc., as reducing agents. Secondary metabolites present in the biological agents act as capping and reducing agents. Green trimetallic nanoparticles can be used for different applications such as anticancer, antibacterial, antifungal, catalytic activity, etc. This review provides an overview of the synthesis of trimetallic nanoparticles using biological agents, and their applications in different areas such as anticancer, antimicrobial activity, drug delivery, catalytic activity, etc. Finally, current challenges, future prospects, and conclusions are highlighted.

Nanotechnology - A new frontier of nano-farming in agricultural and food production and its development

The potential of nanotechnology for the development of sustainable agriculture has been promising. The initiatives to meet the rising food needs of the rapidly growing world population are mainly powered by sustainable agriculture. Nanoparticles are used in agriculture due to their distinct physicochemical characteristics. The interaction of nanomaterials with soil components is strongly determined in terms of soil quality and plant growth. Numerous research has been carried out to investigate how nanoparticles affect the growth and development of plants. Nanotechnology has been applied to improve the quality and reduce post-harvest loss of agricultural products by extending their shelf life, particularly for fruits and vegetables. This review assesses the latest literature on nanotechnology, which is used as a nano-biofertilizer as seen in the agricultural field for high productivity and better growth of plants, an important source of balanced nutrition for the crop, seed germination, and quality enrichment. Additionally, post-harvest food processing and packaging can benefit greatly from the use of nanotechnology to cut down on food waste and contamination. It also critically discusses the mechanisms involved in nanoparticle absorption and translocation within the plants and the synthesis of green nanoparticles.

Polyol-mediated zinc oxide nanoparticles using the refluxing method as an efficient photocatalytic and antimicrobial agent

Nanomaterials have attracted more curiosity recently because of their wide-ranging application in environmental remediation and electronic devices. The current study focuses on zinc oxide nanoparticles' (ZnO NPs) simple production, characterization, and applications in several fields, including medicinal and photocatalytic degradation of dyes. The non-aqueous-based reflux method is helpful for ZnO NP synthesis; the procedure involves refluxing zinc acetate dihydrate precursor in ethylene glycol for 3 hours in the absence of sodium acetate, in which the refluxing rate and the cooling rate are optimized to get the desired phase, and the unique morphology of polyol-mediated ZnO NPs; it has been achieved using the capping agent TBAB (tetra-butyl ammonium bromide) and precursor zinc acetate dihydrate. UV-Vis, FTIR, XRD, and FESEM structurally characterized polyol-mediated ZnO-NPs. The results show that the material is pure and broadly aggregated into spherical nanoparticles with an average particle size of 18.09 nm. According to XRD analysis, heat annealing made the crystallites more prominent and favored a monocrystalline state. These results and the low cost of making polyol-mediated ZnO NPs demonstrate photocatalytic and antimicrobial properties.

Protein encapsulation of nanocatalysts: A feasible approach to facilitate catalytic theranostics

Enzyme-mimicking nanocatalysts, also termed nanozymes, have attracted much attention in recent years. They are considered potential alternatives to natural enzymes due to their multiple catalytic activities and high stability. However, concerns regarding the colloidal stability, catalytic specificity, efficiency and biosafety of nanomaterials in biomedical applications still need to be addressed. Proteins are biodegradable macromolecules that exhibit superior biocompatibility and inherent bioactivities; hence, the protein modification of nanocatalysts is expected to improve their bioavailability to match clinical needs. The diversity of amino acid residues in proteins provides abundant functional groups for the conjugation or encapsulation of nanocatalysts. Moreover, protein encapsulation can not only improve the overall performance of nanocatalysts in biological systems, but also bestow materials with new features, such as targeting and retention in pathological sites. This review aims to report the recent developments and perspectives of protein-encapsulated catalysts in their functional improvements, modification methods and applications in biomedicine.

Recent Advances on Nano-Catalysts for Biological Processes

We are honored to serve as the Guest Editors of this Special Issue entitled “Recent Advances on Nano-Catalysts for Biological Processes” for the journal Catalysts [...]

Mycosynthesis of Metal-Containing Nanoparticles-Fungal Metal Resistance and Mechanisms of Synthesis

In the 21st century, nanomaterials play an increasingly important role in our lives with applications in many sectors, including agriculture, biomedicine, and biosensors. Over the last two decades, extensive research has been conducted to find ways to synthesise nanoparticles (NPs) via mediation with fungi or fungal extracts. Mycosynthesis can potentially be an energy-efficient, highly adjustable, environmentally benign alternative to conventional physico-chemical procedures. This review investigates the role of metal toxicity in fungi on cell growth and biochemical levels, and how their strategies of resistance, i.e., metal chelation, biomineral formation, biosorption, bioaccumulation, compartmentalisation, and efflux of metals from cells, contribute to the synthesis of metal-containing NPs used in different applications, e.g., biomedical, antimicrobial, catalytic, biosensing, and precision agriculture. The role of different synthesis conditions, including that of fungal biomolecules serving as nucleation centres or templates for NP synthesis, reducing agents, or capping agents in the synthesis process, is also discussed. The authors believe that future studies need to focus on the mechanism of NP synthesis, as well as on the influence of such conditions as pH, temperature, biomass, the concentration of the precursors, and volume of the fungal extracts on the efficiency of the mycosynthesis of NPs.

Medical and Dental Applications of Titania Nanoparticles: An Overview

Currently, titanium oxide (TiO₂) nanoparticles are successfully employed in human food, drugs, cosmetics, advanced medicine, and dentistry because of their non-cytotoxic, non-allergic, and bio-compatible nature when used in direct close contact with the human body. These NPs are the most versatile oxides as a result of their acceptable chemical stability, lower cost, strong oxidation properties, high refractive index, and enhanced aesthetics. These NPs are fabricated by conventional (physical and chemical) methods and the latest biological methods (biological, green, and biological derivatives), with their advantages and disadvantages in this epoch. The significance of TiO₂ NPs as a medical material includes drug delivery release, cancer therapy, orthopedic implants, biosensors, instruments, and devices, whereas their significance as a dental biomaterial involves dentifrices, oral antibacterial disinfectants, whitening agents, and adhesives. In addition, TiO₂ NPs play an important role in orthodontics (wires and brackets), endodontics (sealers and obturating materials), maxillofacial surgeries (implants and bone plates), prosthodontics (veneers, crowns, bridges, and acrylic resin dentures), and restorative dentistry (GIC and composites).

Catalytic nanomedicine: a brief review of bionanocatalysts

Catalytic nanomedicine is a research area and source of disruptive technology that studies the application of bionanocatalysts (organically functionalized mesoporous nanostructured materials with catalytic properties) in diverse areas such as disinfection, tissue regeneration in chronic wounds and oncology. This paper reviews the emergence of catalytic nanomedicine in 2006, its basic principles, main achievements and future perspectives, as well as giving a summary of the knowledge gaps that need to be addressed to exploit the full potential of this novel discipline. This review intends to foster knowledge dissemination regarding catalytic nanomedicine, and to encourage further research to elucidate the mechanisms and possible applications of these nanomaterials.

Biogenic Synthesis of Silver Nanoparticles Using Rhazya stricta Extracts and Evaluation of Its Biological Activities

Rhazya stricta is a well-known medicinal plant and source of numerous potential secondary metabolites including steroids, alkaloids, and tannins. R. stricta possesses multimedical applications and used for curing of various diseases such as inflammation, diabetes, sore throat, infectious, helminthiasis, arthritis, and cancer. The current investigation deals with synthesizing AgNPs using aqueous and ethanol extracts of R. stricta. The synthesized R. stricta-AgNPs were characterized through UV-visible, Fourier transform infrared (FTIR), and atomic force microscopy (AFM) methods. The UV-visible analysis exhibited a characteristic absorption ${\lambda }_{\max }$ at 475 nm in R. stricta ethanol AgNPs while this peak was absent in R. stricta aqueous crude extract. The thermal stability of R. stricta-AgNPs demonstrated that by increasing the reduction time and temperature, the absorption of AgNPs also increased, leading to more stable NPs formation. The FTIR spectra showed a broad peak at 450-550 cm-1 that confirmed the occurrence of AgNPs of R. stricta. The AFM study of the synthesized AgNPs revealed the spherical shape and size ranging from 30 nm to 90 nm. In antioxidant and antibacterial study, the R. stricta-AgNPs exhibited good antioxidant activity (87.94% and 88.37%) than the ethanol crude extract (50.00% and 56.81%) at 100 μg/mL using DPPH assay. Maximum antibacterial activity was recorded against Gram-positive bacteria (Staphylococcus aureus), which was 15 and 0 mm, while against Gram-negative bacteria (Klebsiella pneumonia) was found to be 16 and 14 mm, respectively, whereas against Bacillus subtills, a poor activity was recorded as 14 for extract and 0 mm for AgNPs, respectively. In the acetic acid-induced writhing model, the percent effect of extract (100 mg/kg) and AgNPs (15 mg/kg) was 79.98 and 83.23, respectively. The maximum muscle coordination effect of extracts in the inclined plan and traction test was 44% and 38% at higher doses. A mild sedative effect was also recorded against extract and AgNPs. The significant ( $p<0.05$ ) effect of extract was noted at 100 mg/kg while AgNPs was more significant ( $p<0.01$ ) at the tested dose of 15 mg/kg. These findings have concluded that R. stricta-AgNPs is an effective bioreductant of AgNPs synthesis and exhibit several applications in distinctive biomedical and pharmaceutical industries.

Fabrication of Silver Nanoparticles from Ziziphus nummularia Fruit Extract: Effect on Hair Growth Rate and Activity against Selected Bacterial and Fungal Strains

Nanoparticles are extensively used in biomedical and biotechnological research. Their large surface area, excellent physical properties, high permeability, and retention effect make them ideal for biomedical applications including diagnosis and treatment. Silver nanoparticles proved to be the safest for therapeutic uses. In the present study, silver nanoparticles (AgNPs) were prepared using various ratios of Ziziphus nummularia fruit extract and silver nitrate solution. The nanoparticles were investigated for hair growth and antibacterial and antifungal activities. Characterization of AgNPs was done by using UV-spectrophotometer, scanning electron microscope (SEM), X-ray diffractometer (XRD), thermogravimeter (TG), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and master sizer. UV-spectrophotometer results showed the best ratio 10 : 10 of Z. nummularia fruit aqueous extract to silver solution for nanoparticle production at 400 to 430 nm wavelength. The size of AgNPs was 40 nm as measured by SEM. Characterization of AgNPs through EDX resulted in a silver peak at 3 keV. In contrast, differential scanning calorimetry (DSC) spectra show that the AgNPs are stable up to 160°C. The XED spectra gave 12 nm size of crystallite at 2 theta degree angle. FTIR bands for the metal oxides were recorded at 665 cm-1. Weight loss of the prepared nanoparticles was observed due to moisture loss when subjected to TGA, whereas particle size distribution 0.1 μm to 0.17 μm was recorded by the master seizer. The Z. nummularia fruit aqueous extract-mediated AgNPs were noted highly effective against Gram-positive bacteria compared to ethanolic, methanolic, chloroform, and ethyl acetate extracts of Z. nummularia fruit. The Gram-negative bacteria fungal species showed less sensitivity to AgNPs. The hair growth activity was observed to be higher for AgNPs followed by minoxidil than ethanolic and methanolic extracts of Z. nummularia fruit. These findings have concluded that Z. nummularia-AgNPs have an effective hair growth activity and exhibit several applications in distinctive biomedical and pharmaceutical industries.

Natural plant products as effective alternatives to synthetic chemicals for postharvest fruit storage management

Fruits contain enormous source of vitamins that provides energy to the human body. These are also affluent in essential and vital vitamins, minerals, fiber, and health-promoting components, which has led to an increase in fruit consumption in recent years. Though fruit consumption has expanded considerably in recent years, the use of synthetic chemicals to ripen or store fruits has been steadily increasing, resulting in postharvest deterioration. Alternatives to synthetic chemicals should be considered to control this problem. Instead of utilizing synthetic chemicals, this study suggests using natural plant products to control postharvest decay. The aim of this study indicates how natural plant products can be useful and effective to eliminate postharvest diseases rather than using synthetic chemicals. Several electronic databases were investigated as information sources, including Google Scholar, PubMed, Web of Science, Scopus, ScienceDirect, SpringerLink, Semantic Scholar, MEDLINE, and CNKI Scholar. The current review focused on the postharvest of fruits has become more and more necessary because of these vast demands of fruits. Pathogen-induced diseases are the main component and so the vast portion of fruits get wasted after harvest. Besides, it may occur harmful during harvesting and subsequent handling, storage, and marketing and after consumer purchasing and also causes for numerous endogenous and exogenous diseases via activating ROS, oxidative stress, lipid peroxidation, etc. However, pathogenicity can be halted by using postharvest originating natural fruits containing bioactive elements that may be responsible for the management of nutritional deficiency, inflammation, cancer, and so on. However, issues arising during the postharvest diseases must be controlled and resolved before releasing the horticultural commodities for commercialization. Therefore, the control of postharvest pathogens still depends on the use of synthetic fungicides; however, due to the problem of the development of the fungicide-resistant strains there is a good demand of public to eradicate the use of pesticides with the arrival of numerous diseases that are expanded in their intensity by the specific chemical product. By using of the organic or natural products for controlling postharvest diseases of fruits has become a mandatory step to take. In addition, antimicrobial packaging may have a greater impact on long-term food security by lowering the risk of pathogenicity and increasing the longevity of fruit shelf life. Taken together, natural chemicals as acetaldehyde, hexanal, eugenol, linalool, jasmonates, glucosinolates, essential oils, and many plant bioactive are reported for combating of the postharvest illnesses and guide to way of storage of fruits in this review.

Onion Peel Waste Mediated-Green Synthesis of Zinc Oxide Nanoparticles and Their Phytotoxicity on Mung Bean and Wheat Plant Growth

Nanoparticles and nanomaterials have gained a huge amount of attention in the last decade due to their unique and remarkable properties. Metallic nanoparticles like zinc oxide nanoparticles (ZnONPs) have been used very widely as plant nutrients and in wastewater treatment. Here, ZnONPs were synthesized by using onion peel and characterized by various sophisticated instruments like Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and field emission scanning electron microscopes (FESEM). FTIR confirmed ZnONPs synthesis due to the formation of the band in the region of 400-800 cm^-1, while FESEM confirmed the spherical shape of the particles whose size varies in the range of 20-80 nm. FTIR revealed several bands from 1000-1800 cm^-1 which indicates the capping by the organic molecules on the ZnONPs, which came from onion peel. It also has carbonyl and hydroxyl groups, due to the organic molecules present in the Allium cepa peel waste. The average hydrodynamic size of ZnONPs was 500 nm as confirmed by DLS. The synthesized ZnONPs were then used as a plant nutrient where their effect was evaluated on the growth of Vigna radiate (mung bean) and Triticum aestivum (wheat seeds). The results revealed that the germination and seedling of mung and wheat seeds with ZnONPs were grown better than the control seed. However, seeds of mung and wheat with ZnONPs at median concentration exposure showed an enhancement in percent germination, root, and shoot length in comparison to control. Thus, the effect of ZnONPs has been proved as a nano-based nutrient source for agricultural purposes.

Biogenic Synthesis of AgNPs Using Aqueous Bark Extract of Aesculus indica for Antioxidant and Antimicrobial Applications

Nanotechnology has received a lot of attention from the scientific community because of the greater surface-to-volume ratio of nanomaterials, which phenomenally increases their efficacy in practical applications. Among the various synthesis techniques, the biogenic or green synthesis of nanomaterials shows advantages over other techniques such as physical, chemical, etc. This study reports the biogenic synthesis of silver nanoparticles (AgNPs) using aqueous bark extract of Aesculus indica. The as-synthesized NPs were characterized by UV–visible, FT-IR, XRD, and SEM, and then tested for their antioxidant and antimicrobial potency. We have identified phenols, flavonoids, tannins, saponins, and carbohydrates in the bark extract of A. indica. The extract-loaded-AgNPs showed the highest inhibition for Staphylococcus aureus (28.0 mm), Pseudomonas aeruginosa (17.66 mm), Escherichia coli (14.33 mm), Acetobacter serratia (14.00 mm), and Klebsiella pneumoniae (12.33 mm). The methanolic bark extract inhibited S. aureus (24.33 mm), P. aeruginosa (10.66 mm), E. coli (11.33 mm), A. serratia (9.66 mm), and K. pneumoniae (11.66 mm). Aqueous bark extract inhibited S. aureus (22.33 mm), P. aeruginosa (8.33 mm), E. coli (9.33 mm), A. serratiaa (8.33 mm), and K. pneumoniae (9.66 mm). Its aqueous extract showed the highest antioxidant potency; IC50 (0.175 µg/mL) followed by the methanolic extract; IC50 (0.210 µg/mL) and extract-loaded nanoparticles; IC50 (0.901 µg/mL). Our findings provide meaningful interest for antioxidant, anti-microbial applications of, and AgNPs synthesis by, aqueous bark extract of A. indica.

Biogenic Synthesis of Ag Nanoparticles of 18.27 nm by Zanthozylum armatum and Determination of Biological Potentials

Nanotechnology has become a dire need of the current era and the green synthesis of nanoparticles offers several advantages over other methods. Nanobiotechnology is an emerging field that contributes to many domains of human life, such as the formulation of nanoscale drug systems or nanomedicine for the diagnosis and treatment of diseases. Medicinal plants are the main sources of lead compounds, drug candidates and drugs. This work reports the green synthesis of Ag nanoparticles (AgNPs) using the aqueous bark extract of Zanthozylum armatum, which was confirmed by a UV absorption at 457 nm. XRD analysis revealed an average size of 18.27 nm and SEM showed the particles’ spherical shape, with few irregularly shaped particles due to the aggregation of the AgNPs. FT-IR revealed the critical functional groups of phytochemicals which acted as reducing and stabilizing agents. The bark extract showed rich flavonoids (333 mg RE/g) and phenolic contents (82 mg GAE/g), which were plausibly responsible for its high antioxidant potency (IC₅₀ = 14.61 µg/mL). Extract-loaded AgNPs exhibited the highest but equal inhibition against E. coli and P. aeruginosa (Z.I. 11.0 mm), whereas methanolic bark extract inhibited to a lesser extent, but equally to both pathogens (Z.I. 6.0 mm). The aqueous bark extract inhibited P. aeruginosa (Z.I. 9.0 mm) and (Z.I. 6.0 mm) E. coli. These findings—especially the biosynthesis of spherical AgNPs of 18.27 nm—provide promise for further investigation and for the development of commercializable biomedical products.

Sensing beyond Senses: An Overview of Outstanding Strides in Architecting Nanopolymer-Enabled Sensors for Biomedical Applications

Nano-enabled sensing is an expanding interdisciplinary field of emerging science with dynamic multifunctional detecting capabilities, equipped with a wide range of multi-faceted nanomaterial having diverse dimensions and composition. They have proven to be highly robust, sensitive, and useful diagnostic tools ranging from advanced industrial processes to ordinary consumer products. As no single nanomaterial has proved to be unparalleled, recent years has witnessed a large number of nanomaterial-based sensing strategies for rapid detection and quantification of processes and substances with a high degree of reliability. Nano-furnished platforms, because of easy fabrication methods and chemical versatility, can serve as ideal sensing means through different transduction mechanisms. This article, through a unified experimental-theoretical approach, uses literature of recent years to introduce, evaluate, and analyze significant developments in the area of nanotechnology-aided sensors incorporating the various classes of nanomaterial. Addressing the broad interests, the work also summarizes the sensing mechanisms using schematic illustrations, attempts to integrate the performance of different categories of nanomaterials in the design of sensors, knowledge gaps, regulatory aspects, future research directions, and challenges of implementing such techniques in standalone devices. In view of a dependency of analysis and testing on sustained growth of sensor-supported platforms, this article inspires the scientific community for more attention in this field.

Antibacterial and Dye Degradation Activity of Green Synthesized Iron Nanoparticles

Nanoparticles have a wide range of applications in various fields such as cosmetics, pharmaceuticals, and agrochemicals. Synthesis of nanoparticles using plant extract is a very efficient, cost-effective, useful, and environmentally friendly method. A plant extract acts as a reducing agent in the formation of nanoparticles. Catharanthus roseus is one of the potential plants for biosynthesis of nanoparticles due to its easy availability. In the present study, the Catharanthus roseus plant extract was used to synthesize iron nanoparticles. UV-vis spectroscopy, DLS, and FTIR were performed for characterization of synthesized nanoparticles. Further antibacterial and dye degrading properties of synthesized iron nanoparticles have been investigated. It was found that Catharanthus roseus-synthesized iron nanoparticles showed antibacterial activity against E. coli and dye degradation activity against methyl orange dye.