Green Synthesis Of Nanomaterials Research Articles

Green synthesis of nanomaterials by using plant extracts as reducing and capping agents.

An alternative method to conventional synthesis is examined in this review by the use of plant extracts as reducing and capping agents. The use of plant extracts represents an economically viable and environmentally friendly alternative to conventional synthesis. In contrast to previous reviews, this review focuses on the synthesis of nano-compounds utilizing plant extracts, which lack comprehensive reports. In order to synthesize diverse nanostructures, researchers have discovered a sustainable and cost-effective method of harnessing functional groups in plant extracts. Each plant extract is discussed in detail, along with its potential applications, demonstrating the remarkable morphological diversity achieved by using these green synthesis approaches. A reduction and capping agent made from plant extracts is aligned with the principles of green chemistry and offers economic advantages as well as paving the way for industrial applications. In this review, it is discussed the significance of using plant extracts to synthesize nano-compounds, emphasizing their potential to shape the future of nanomaterials in a sustainable and ecologically friendly manner.

Green magnetic snail shell hydroxyapatite sorbent for reliable solid-phase extraction of pesticides from water samples.

To address sustainability issues, the green synthesis of nanomaterials has recently received considerable attention. This article addresses a novel and cost-effective adsorbent for the extraction of eight phenyl-N-methylcarbamate insecticides from water samples. We first synthesized a magnetite/hydroxyapatite nanocomposite using snail shell powder via an environmental friendly approach. The morphology and physicochemical properties of magnetic hydroxyapatite were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Magnetic extraction parameters were optimized using a Doehlert matrix. Under optimum conditions, the magnetic extraction coupled with a LC-MS method shows good linearity with R2 ≥ 0.9982, suitable intra- and interday precision, and limits of detection and quantification in the range of 0.052-0.093μg/L and 0.11-0.31μg/L, respectively. Satisfactory relative recoveries of all carbamates were achieved from fortified water samples in the range of 93.89-101.01%.

Colorimetric sensor based on biogenic nanomaterials for high sensitive detection of hydrogen peroxide and multi-metals

Hydrogen peroxide (H2O2) and heavy metals, which are among the wastes of the industrial sector, become a threat to living things and the environment above certain concentrations. Therefore, the detection of both H2O2 and heavy metals with simple, low-cost, and fast analytical methods has gained great importance. The use of nanoparticles in colorimetric sensor technology for the detection of these analytes provides great advantages. In recent years, green synthesis of nanomaterials with products that can be considered biowaste is among the popular topics. In this study, silver/silver chloride nanoparticles (Ag@AgCl NPs) were synthesized using the green synthesis method as an eco-friendly and cheap method, the green algae extract was used as a reducing agent. The characterization of Ag@AgCl nanoparticles and green algae extract was carried out with several techniques such as Transmission Electron Microscopy (TEM), UV–Visible spectrometry (UV–Vis), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction patterns (XRD) methods were used for characterization. According to TEM analysis, the Ag@AgCl NPs typically spherical in form and range in size from 4 to 10 nm, and UV–vis showed the formation of surface plasmon resonance (SPR) of the Ag@AgCl between 400 and 450 nm. In addition, its activity as a colorimetric sensor for hydrogen peroxide (H2O2) and multi-metal detection was evaluated. Interestingly, Ag/AgCl NPs caused different color formations for 3 metals simultaneously in the sensor study for heavy metal detection, and Fe3+, Cu2+, and Cr6+ ions were detected. The R2 values for H2O2, Fe3+, Cu2+, and Cr6+ were 0.9360, 0.9961, 0.9787, and 0.9625 the limit of detection (LOD) was 43.75, 1.69, 3.18, and 5.05 ppb (ng/mL), respectively. It was determined that Ag@AgCl NPs have the potential to be used as a colorimetric sensor for the detection of H2O2 and heavy metals from wastewater.

Marine Actinobacterial Streptomyces Sp., Mediated Synthesis of Silver Nanoparticles: Characterization and Different Biological Properties Under In-vitro Condition

Background: Green synthesis of nanomaterials is promising as a biological source for treating different diseases without side effects. Methods: In the present study, marine Streptomyces sp. was used to biosynthesize silver nanoparticles, which were then characterized and evaluated for various therapeutic activities and A 549 breast cancer cell line for cytotoxic evaluation. Results: The Surface Plasmon Resonance exhibited a peak at 434 nm, and the FT-IR spectrum of St- AgNPs revealed the presence of secondary metabolites, which were used for stabilization and capping processes. The St-AgNPs showed an agglomerated spherical shape with a diameter of 10–35 nm. The elemental composition was silver (60.0%), oxygen (14.9%), sodium (14.9%), and carbon (15.0%). The St-AgNPs exhibited significant antioxidant activity in terms of DPPH 62.2 ± 2.1, H2O2 57.76 ± 2.4%, TAA 64.3±2.7, and NO 64.3 ± 2.7 at 100 μg/mL. The cytotoxic activity using A 549 Breast cancer cell line was found to be only 20 % of viable cells at 100 μg concentration. St-AgNPs revealed good antibacterial efficacy against Streptococcus mutants, Klebsiella Sp. and Staphylococcus aureus (MRSA). Conclusion:: The St-AgNPs may be a good choice for antibacterial, antioxidant and cytotoxic agents in the future with further relevant study and may be used in the field of nano biomedicine.

Green synthesis of Cu-Mn co-incorporated ZnO nanoparticles for antibacterial and photocatalytic applications.

The synergistic effect of bimetallic co-incorporated metal oxides have gained enormous attention due to their unique optoelectronic properties. Herein, we present the green synthesis of ZnO, Cu-incorporated ZnO, Mn-incorporated ZnO, and Cu-Mnco-incorporated nanoparticles (ZnO NPs, CuZnO NPs, MnZnO NPs, MnCuZnO NPs) for antimicrobial and photocatalytic reduction applications using corn silk extract and industrial metal wastes. The as-synthesized NPs were characterized by using UV-visible absorption spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy, Fourier-transformed infrared spectroscopy (FT-IR), powdered x-ray diffraction (XRD), and scanning electron microscopy (SEM). CuZnO, MnZnO, and MnCuZnO NPs efficiently inhibited bacterial culture growth. The photocatalytic reduction activity of as-synthesized NPs against the different concentrations of 4-nitrophenol (4-NP) in water was also investigated. CuZnO and MnCuZnO nanoparticles were to be efficient photocatalysts for reducing 4-NP into 4-aminophenol (4-AP). RESEARCH HIGHLIGHTS: Green synthesis of nanomaterials by agricultural and industrial wastes Cu and Mn co-incorporated ZnO NPs have shown good photocatalysis and antimicrobial activities Green approach for waste conversion to value-added products.

Biosynthesis of phyto-functionalized silver nanoparticles using olive fruit extract and evaluation of their antibacterial and antioxidant properties.

The green synthesis of nanomaterials is of utmost interest as it offers an eco-friendly approach over chemical synthetic routes. However, the reported biosynthesis methods are often time-consuming and require heating or mechanical stirring. The current study reports a facile one-pot biosynthesis of silver nanoparticles (AgNPs) mediated by olive fruit extract (OFE) and sunlight irradiation of only 20s. OFE acts as both a reducing and a capping agent for the formation of OFE-capped AgNPs (AgNPs@OFE). The as-synthesized NPs were systematically characterized by UV-vis spectrometry, Fourier transform infrared (FTIR) spectroscopy, scanning electrochemical microscopy with energy-dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), dynamic light scattering (DLS), and cyclic voltammetry. SEM images confirmed the successful formation of monodispersed spherical AgNPs@OFE of approximately 77nm. FTIR spectroscopy suggested the involvement of functional groups of phytochemicals from the OFE in the capping and reduction of Ag+ to Ag. The particles revealed excellent colloidal stability as evidenced from the high zeta potential (ZP) value (-40mV). Interestingly, using the disk diffusion method, AgNPs@OFE revealed higher inhibition efficiency against Gram-negative bacteria (Escherichia coli, Klebsiella oxytoca, and extensively drug-resistant (XDR) Salmonella typhi) than Gram-positive bacteria (Staphylococcus aureus), with Escherichia coli showing the highest inhibition zone of 27mm. In addition, AgNPs@OFE exhibited maximum potent antioxidant scavenging potential against H2O2, followed by DPPH, O2 -, and OH- free radicals. Overall, OFE can be considered an effective source for the sustainable production of stable AgNPs with potential antioxidant and antibacterial activities for biomedical applications.

Biosynthesis of Silver Nanoparticles Using the Biofilm Supernatant of Pseudomonas aeruginosa PA75 and Evaluation of Their Antibacterial, Antibiofilm, and Antitumor Activities.

As an under-explored biomaterial, bacterial biofilms have a wide range of applications in the green synthesis of nanomaterials. The biofilm supernatant of Pseudomonas aeruginosa PA75 was used to synthesize novel silver nanoparticles (AgNPs). BF75-AgNPs were found to possess several biological properties. In this study, we biosynthesized BF75-AgNPs using biofilm supernatant as the reducing agent, stabilizer, and dispersant and investigated their biopotential in terms of antibacterial, antibiofilm, and antitumor activities. The synthesized BF75-AgNPs demonstrated a typical face-centered cubic crystal structure; they were well dispersed; and they were spherical with a size of 13.899 ± 4.036 nm. The average zeta potential of the BF75-AgNPs was -31.0 ± 8.1 mV. The BF75-AgNPs exhibited strong antibacterial activities against the methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase Escherichia coli (ESBL-EC), extensively drug-resistant Klebsiella pneumoniae (XDR-KP), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA). Moreover, the BF75-AgNPs had a strong bactericidal effect on XDR-KP at 1/2 × MIC, and the expression level of reactive oxygen species (ROS) in bacteria was significantly increased. A synergistic effect was observed when the BF75-AgNPs and colistin were used for the co-treatment of two colistin-resistant XDR-KP strains, with fractional inhibitory concentration index (FICI) values of 0.281 and 0.187, respectively. Furthermore, the BF75-AgNPs demonstrated a strong biofilm inhibition activity and mature biofilm bactericidal activity against XDR-KP. The BF75-AgNPs also exhibited a strong antitumor activity against melanoma cells and low cytotoxicity against normal epidermal cells. In addition, the BF75-AgNPs increased the proportion of apoptotic cells in two melanoma cell lines, and the proportion of late apoptotic cells increased with BF75-AgNP concentration. This study suggests that BF75-AgNPs synthesized from biofilm supernatant have broad prospects for antibacterial, antibiofilm, and antitumor applications.

A Green Synthesis Method to Tune the Morphology of CuO and ZnO Nanostructures

Background: Green synthesis of nanomaterials has gained interest over the years as it has many benefits compared to conventional methods. Green methods are non-toxic and economic due to the use of aqueous extracts as reducing agents. Yerba mate is a widely used herb in South America, showing an available and economical alternative to conventional methods Methods: Different copper and zinc nanostructures were obtained using yerba mate extract (Ilex paraguariensis) as a reducing and capping agent. Furthermore, adjusting NaCl concentration and temperature, it was possible to successfully tune and examine the morphology of the resulting nanostructures by Scanning Electron Microscopy (SEM). Phenolic oxidation was evaluated by Raman spectroscopy and Fourier Transform Infrared Spectroscopy (FT-IR) to assess the role of yerba mate extract in the reaction. Moreover, antimicrobial activity versus Pseudomonas aeruginosa was assayed, and antioxidant activity was performed by the DPPH method. Results and Conclusion: The present study reveals a powerful method to obtain zinc and copper nanostructures, showing a logarithmic reduction of Pseudomonas aeruginosa of 2.14 and 5.92 CFU/mL at 96 hours respectively and scavenger activity of 42% and 22%, respectively. These properties highlight the potential of the nanomaterials for applications in catalysis, textile, biomedical and agricultural fields.

Green synthesis of zinc oxide nanoparticles using Brassica oleracea var. botrytis leaf extract: Photocatalytic, antimicrobial and larvicidal activity

Green synthesis of nanomaterials has emerged as an ecofriendly sustainable technology for the removal of dyes in the last few decades. Especially, plant leaf extracts have been considered as inexpensive and effective materials for the synthesis of nanoparticles. In this study, zinc oxide nanoparticles (ZnO NPs) were prepared using leaves extract of Brassica oleracea var. botrytis (BO) by co-precipitation and applied for photocatalytic/antibacterial activity. The synthesized BO-ZnO NPs was characterized by different instrumental techniques. The UV–vis Spectrum of the synthesized material showed maximum absorbance at a wavelength of 311 nm, which confirmed the formation of BO-ZnO NPs. The XRD pattern of BO-ZnO NPs represents a hexagonal wurtzite structure and the average size of particles was about 52 nm. FT-IR spectrum analysis confirms the presence of hydroxyl, carbonyl, carboxylic, and phenol groups. SEM images exhibited a flower like morphology and EDX spectrum confirming the presence of the elements Zn and O. Photo-catalytic activity of BO-ZnO NPs was tested against thiazine dye (methylene blue-MB) degradation under direct sunlight irradiation. Around 80% of the MB dye got degraded at pH 8 under 75 min of sunlight irradiation. Further, the study examined that the antimicrobial and larvicidal activity of BO-ZnO NPs obtained through green synthesis. The antimicrobial study results showed that the BO-ZnO NPs formed zones against bacterial pathogens. The results showed the formation of an inhibition zone against B. subtills (16 mm), S.aureus (13 mm), K. pneumonia (13 mm), and E. coli (9 mm) respectively at a concentration of 100 μg/mL of BO-ZnO NPs. The larvicidal activity of the BO-ZnO NPs was tested against the fourth instar of Culex quinquefasciatus mosquito larvae The LC50 and LC90 values estimated through the larvicidal activity of BO-ZnO NPs were 76.03, 190.03 ppm respectively. Hence the above findings propose the synthesized BO-ZnO NPs by the ecofriendly method can be used for various environmental and antipathogenic applications.

Nd2O3-Ag Nanostructures for Plasmonic Biosensing, Antimicrobial, and Anticancer Applications

Green synthesis of nanomaterials with multifaceted applications in photonics as well as biomedical fields has remained a daunting challenge. Engineering multielement nanohybrid libraries with synergistic surface functionalities from dielectric and metallic nanocomponents using sustainable approaches is seldom reported. In this context, we demonstrate a 1 min, user- and eco-friendly, sunlight-based green synthesis of Nd2O3-Ag, dielectric–metal ferroplasmon nanohybrids with detailed elucidation of the mechanism. Chemical anchoring of plasmonic Ag on high refractive index (n = 1.94), rare-earth Nd2O3 nanorods (average aspect ratio: ∼3) alleviates Ohmic losses without damping the plasmon resonances. Ferroplasmon-on-a-mirror (FPoM), an analogue to conventional nanoparticle-on-a-mirror (NPoM), is presented for efficient coupling of s-polarized light on account of magnetic flux modes supported by it. Apart from realization of room temperature ferromagnetism (RTFM) for nanophotonic applications, the judicious metal–nonmetal combination displayed excellent bactericidal, fungicidal, antioxidant, and anticancer properties, establishing a convergent “one health perspective” of engineered nanohybrids. Whereas the unconventional s-polarized plasmon-coupled emission obtained is utilized for sensing of food hazard Allura Red (limit of detection, LOD: 10 aM) in the FPoM platform, the p-polarized emission is used for 4-nitrophenol sensing (LOD: 100 fM). Excellent correlation between the exceptionally high Purcell factor (of 6.5 × 105 for the composite nanohybrid Nd2O3-Ag-carbon dot-graphene oxide) from simulations and experimentally obtained plasmon-coupled >2000-fold fluorescence emission enhancements is demonstrated. The utility of the proposed sunlight-induced nanoengineering to generate a library of nanocomposites comprising dielectric, metal, and graphitic plasmons is presented. We believe that the proposed methodology to generate hybrid nanomaterials with intriguing FPoM interfaces would be utilized for transdisciplinary nanophotonics as well as biomedical sensing applications.

Phytotoxicity and Antimicrobial Activity of Green Synthesized Silver Nanoparticles Using Nigella sativa Seeds on Wheat Seedlings

Recently, the green synthesis of nanomaterials has grown in popularity and has become one of the most used approaches. Plant extracts are safe for the environment and could be cost-effective for nanoparticle preparation. Silver nanoparticles (AgNPs) have been synthesized using aqueous extracts of Nigella sativa (N. sativa) seeds. The formation of AgNPs was confirmed by using an X-ray diffractometer, a UV-visible spectrometer, and a transmission electron microscope. The phytotoxicity and genotoxicity of different AgNP concentrations (12.5, 25, 50, 75, and 100 μg·L−1) were evaluated by wheat (Triticum aestivum L.) seed germination. The results showed that AgNPs did not significantly affect germination, while root and coleoptile lengths decreased considerably. On the contrary, the biomass of seedlings markedly increased in response to AgNP treatments. Moreover, genotoxicity was detected, especially at high concentrations of AgNPs. DNA, RNA, and total soluble proteins of wheat seedlings significantly decreased. In addition, antimicrobial activities of biosynthesized AgNPs were detected.

Nano-inspired smart medicines targeting brain cancer: diagnosis and treatment.

Cancer, despite being the bull's eye for the research community, accounts for a large number of morbidity and mortality. Cancer of the brain is considered the most intractable, with the least diagnosis rates, hence treatment and survival. Despite the extensive development of therapeutic molecules, their targeting to the diseased site is a challenge. Specially tailored nanoparticles can efficiently deliver drugs and genes to the brain to treat tumours and diseases. These nanotechnology-based strategies target the blood-brain barrier, the local space, or a specific cell type. These nanoparticles are preferred over other forms of targeted drug delivery due to the chances for controlled delivery of therapeutic cargo to the intended receptor. Targeted cancer therapy involves using specific receptor-blocking compounds that block the spreading or growth of cancerous cells. This review presents an account of the recent applications of nano-based cancer theragnostic, which deal in conjunct functionalities of nanoparticles for effective diagnosis and treatment of cancer. It commences with an introduction to tumours of the brain and their grades, followed by hurdles in its conventional diagnosis and treatment. The characteristic mechanism of nanoparticles for efficiently tracing brain tumour grade and delivery of therapeutic genes or drugs has been summarised. Nanocarriers like liposomes have been widely used and commercialized for human brain cancer treatment. However, nano-inspired structures await their translational recognition. The green synthesis of nanomaterials and their advantages have been discussed. The article highlights the challenges in the nano-modulation of brain cancer and its future outlook.

Green synthesis of silver nanoparticles using medicinal Fern Blenchnum Orientale leaves and its application as an antimicrobial agent against food borne pathogens

Nanotechnology is the most active research area in modern materials science. Though there are numerous chemical and physical methods, green synthesis of nanomaterials is the most recent. In the present study, silver nanoparticles were synthesized by plant mediated green approach method using leaf extracts of medicinal fern Blechnum orientale Linn, provides necessary bioactive for reduction of silver ions to silver nanoparticles. Blechnum orientale was commonly known as ‘Centipede fern’, which is an important edible medicinal fern. Synthesized nanoparticles were elucidated using UV-visible spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), surface emission microscopy analysis (SEM) and its antioxidant activity was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as well as antimicrobial properties were studied against common food-borne pathogens. The highest absorbance of the produced silver nano particles (AgNPs) was 433 nm and the conversion of Ag+ ions to AgNPs was validated using Fourier transform infrared spectroscopy. FTIR result revealed the existence of O–H stretching and N–H amide group peaks. The as-synthesized AgNPs exhibited effective antibacterial action against food borne pathogens E. coli, Salmonella typhi, Pseudomonas aeruginosa and Shigella dysenteriae.

The Ecogeographical Impact of Air Pollution in the Azerbaijan Cities: Possible Plant/Synthetic-Based Nanomaterial Solutions

The current paper deals with the major causes of air pollution in the big cities of Azerbaijan. In this context, industrial gas wastes and transport systems are the most important sources of air pollution. Also, relevant factors following the intensity of air pollution have recently been recognized. The motor transport system and its detrimental effects on human health are tightly connected with air pollution. Therefore, the use of ecological and geographical data could be an efficient approach to preventing air pollution in urban regions. Also, the advantage of nanotechnology in removing air contaminants has been introduced as a promising solution. Nanomaterials can serve as nano adsorbents, nanocatalysts, nano filters/membranes, and nanosensors in air pollution remediation. Moreover, the green synthesis of nanomaterials from plant-based origins is promising in this context. Also, nanotechnology is a robust candidate for the production of green and sustainable energy resources. In a nutshell, recommendations on the prevention and alleviation of air pollution, as well as the methods of refining the urban environment and controlling polluting agents are represented.

An insight into the green synthesis of SiO2 nanostructures as a novel adsorbent for removal of toxic water pollutants

Green synthesis of nanomaterials is a sustainable, biologically safe, reliable, and eco-friendly approach. Green synthesis is beneficial to reduce the devastating effects of the traditional chemical synthesis methods and particularly aims at decreasing the usage of toxic chemicals. This review deals with the green synthesis of silica nanoparticles (SiO2 NPs) with emphasis on the engineering surface properties for enhanced adsorption capability and their applications as novel nano-adsorbents for water pollutants removal. Green synthesized SiO2 NPs have shown excellent adsorption properties with higher adsorption capacity of 150-200 mg/g and more than 95% removal for various toxic water pollutants along with reusability for more than 5 cycles. These SiO2 NPs show fascinating physical and chemical properties i.e. tunable size (5 nm to more than 100 nm), low toxicity, biocompatibility, high porosity, higher specific surface area (500–-700 m2/g) making them attractive/suitable for several applications in biomedical, agriculture, catalysis, construction, water treatment, etc. Commonly, highly pure SiO2 NPs are synthesized from organic chemicals (very expensive and highly toxic in nature) as a precursor that led to high production costs, high energy consumption, and environmental hazards. On the other hand, green synthesis of SiO2 NPs from natural resources like biomass that includes rice husk, bamboo leaves/stem, sugarcane bagasse, corn cobs, wheat straw, etc. is cost-effective, less toxic, and eco-friendly which has been discussed in detail. Furthermore, the effect of key synthesis parameters (i.e., temperature, time, concentration, pH, etc.) on the morphology, size, purity, and specific surface area of SiO2 NPs have been summarized. Finally, the applications of SiO2 NPs as nano-adsorbents for the removal of toxic water pollutants (i.e., heavy metal cations, anions, dyes, etc.) including the adsorption mechanisms along with the future scope, challenges, and suggestions have been discussed.

Green Synthesis of Nanomaterials and Their Utilization as Potential Vehicles for Targeted Cancer Drug Delivery

A nanoparticle (NP) is a microscopic particle with a length of two or three dimensions greater than 0.001 micrometer (1 nanometer =10⁻⁹ metre). NPs may be classified into different classes based on their specific properties, shapes or sizes, and high surface area-to-volume ratio. Nanoparticles have a remarkable capacity as 'magic bullets' stacked with herbicides, fungicides, supplements, fertilizers or nucleic acids, specializing in expressing plant tissues to deliver their charge to the appropriate piece of the plant to perform desired outcomes. The smart design and synthesis of a library of nanomaterials, exact control over their physicochemical properties and simplicity of their surface functionalization to assemble explicitness is to be certain fundamental for the achievement of disease treatment and harmfulness in the biological systems. Green techniques for nanomaterial synthesis observe natural organic systems to nanomaterial production. Green synthesized nanomaterials are at present powerful and significant tools for protecting the drug from the dangerous surroundings in addition to overcoming the organic obstacles to access of the drug in targeted tissues and dealing with drug resistance. NPs were extensively utilized in numerous biomedical applications, site-specific drug delivery systems and cellular uptake because of their inert nature, stability, high dispersity, non-cytotoxicity, and biocompatibility. Nanoparticles may be programmed for recognizing the cancerous cells and giving selective and correct drug delivery avoiding interaction with the healthy cells. However, usage of those NPs is restrained through factors like lack of stability in adversarial environment, concerns regarding bioaccumulation and toxicity, need of relatively trained employees for device assembly and operation, and problems with reproducibility and affordability.

Study of the optical properties of TiO2 semiconductor nanoparticles synthesized using Salvia rosmarinus and its effect on photocatalytic activity

In recent years, the green synthesis of nanomaterials has gained interest as an efficient and environmentally friendly method for obtaining metal oxide nanoparticles. This work presents a study on the effect of Salvia rosmarinus extract in the optical properties and photocatalytic activity of titanium oxide (TiO2) nanoparticles (NPs) synthetized through a green route. Titanium tetrachloride (TiCl4) was used as the Ti source, while Salvia rosmarinus extract with different amounts (1%, 2%, and 4% w/v) was used as a stabilizing agent. Fourier-transform infrared spectroscopy (FTIR) characterization shows the presence of the Ti–O–Ti band at 408 cm−1, while X-ray diffraction (XRD) results identified the crystalline structure of anatase phase TiO2 with no impurities and scanning electron microscope (SEM) images showed a spherical shape with agglomerations. The calculated band gap values decreased from 3.21 eV to 2.93 eV as the extract concentration increased. The NPs showed great photocatalytic activity under solar irradiation, achieving over 90% degradation for methylene blue (MB) in just 20 min. Additionally, the NPs showed great degradation of methyl orange (MO), and rhodamine B (RhB) under UV irradiation, with the best sample reaching over 90% degradation in under 60 min of exposure.

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.

Green Synthesis of Nanomaterials and Their Biological Applications

Nanomaterials possess valuable physical and chemical properties, which may make them excellent candidates for the development of new insecticides, acaricides, fungicides, drugs, catalysts, and sensors, to cite just some key categories [...]

Light Tailoring: Impact of UV-C Irradiation on Biosynthesis, Physiognomies, and Clinical Activities of Morus macroura-Mediated Monometallic (Ag and ZnO) and Bimetallic (Ag-ZnO) Nanoparticles.

A nano-revolution based on the green synthesis of nanomaterials could affect all areas of human life, and nanotechnology represents a propitious platform for various biomedical applications. During the synthesis of nanoparticles, various factors can control their physiognomies and clinical activities. Light is one of the major physical factors that can play an important role in tuning/refining the properties of nanoparticles. In this study, biocompatible monometallic (AgNPs and ZnONPs) and bimetallic Ag–ZnONPs (0.1/0.1 and 0.1/0.5) were synthesized under UV-C light irradiation from the leaf extract of Morus macroura, which possesses enriched TPC (4.238 ± 0.26 mg GAE/g DW) and TFC (1.073 ± 0.18 mg QE/g DW), as well as strong FRSA (82.39%). These green synthesized NPs were evaluated for their anti-diabetic, anti-glycation, and biocompatibility activities. Furthermore, their anti-cancerous activity against HepG2 cell lines was assessed in terms of cell viability, production of reactive oxygen/nitrogen species, mitochondrial membrane potential, and apoptotic caspase-3/7 expression and activity. Synthesized NPs were characterized by techniques including ultraviolet-visible spectroscopy, SEM, EDX, FTIR, and XRD. UV-C mediated monometallic and bimetallic NPs showed well-defined characteristic shapes with a more disperse particle distribution, definite crystalline structures, and reduced sizes as compared to their respective controls. In the case of clinical activities, the highest anti-diabetic activity (67.77 ± 3.29% against α-amylase and 35.83 ± 2.40% against α-glucosidase) and anti-glycation activity (37.68 ± 3.34% against pentosidine-like AGEs and 67.87 ± 2.99% against vesperlysine-like AGEs) was shown by UV-C mediated AgNPs. The highest biocompatibility (IC50 = 14.23 ± 1.68 µg/mL against brine shrimp and 2.48 ± 0.32% hemolysis of human red blood cells) was shown by UV-C mediated ZnONPs. In the case of anti-cancerous activities, the lowest viability (23.45 ± 1.40%) with enhanced ROS/NOS production led to a significant disruption of mitochondrial membrane potential and greater caspase-3/7 gene expression and activity by UV-C mediated bimetallic Ag–ZnONPs (0.1/0.5). The present work highlights the positive effects of UV-C light on physico-chemical physiognomies as well as the clinical activities of NPs.