Green ecofriendly electrochemical sensing platform for the sensitive determination of doxycycline.

The detection of pharmaceutical compounds in extremely low concentrations remains a challenge despite recent advancements in electrochemical sensing. In this study, a green hydrothermally synthesized nickel hydroxide-graphene hybrid material was used for the point-of-care determination of the antibiotic doxycycline (DOXY), which is a promising treatment for COVID-19 and other infections. The electrochemical sensor, based on a screen-printed electrode modified with the hybrid material, was able to detect DOXY in the range of 5.1 × 10-8 to 1.0 × 10-4 M, with a low detection limit of 9.6 × 10-9 M. This approach paves the way for eco-friendly and sustainable methods of nanomaterial synthesis for electrochemical analyses, particularly in point-of-care drug monitoring, and has the potential to improve access to testing platforms.

GREEN SYNTHESIS OF SILICON DIOXIDE NANOPARTICLES AND L ARGININE@SILICON DIOXIDE NANOCOMPOSITES USING CELLULOSE OF ZIZYPHUS SPINA-CHRISTI ALONG WITH BIOLOGICAL EVALUATION

The recent research focused on the green synthesis of silicon dioxide nanoparticles, SiO2@Cellulose of Zizyphus Spina-Christi nanocomposites, and L-Arginine@SiO2@Cellulose of Zizyphus Spina-Christi nanocomposites using cellulose of Zizyphus Spina-Christi as a new green polymeric surfactant. The structures of nanoparticles and nanocomposites were characterized by different spectroscopy and microscopy techniques. Nanoparticles and nanocomposites were utilized to determine the concentration of chromium, cadmium, and lead in COVID-19 patients using double-vortex-ultrasonic assisted surfactant enhanced dispersive liquid-liquid microextraction. Mean recoveries of chromium, cadmium, and lead were obtained in the range of 86-98% with relative standard deviations below 4%. The advantages of the proposed method are green and novel polymer surfactant with low detection limit. Finally, antibacterial activities were investigated. The maximum inhibition zone of L-Arginine@SiO2@Cellulose of Zizyphus Spina-Christi nanocomposites was obtained for Staphylococcus Aureus (21.9±0.4 mm). L-Arginine@SiO2@Cellulose of Zizyphus Spina-Christi nanocomposites have low cytotoxicity against MCF-7 cancer cells. These results indicated the potential ability of L-Arginine@SiO2@Cellulose of Zizyphus Spina-Christi nanocomposites in the determination of metal concentrations in biological samples along with good antibacterial properties and cytotoxic properties. © 2023 Chemical Society of Ethiopia and The Authors.

Burdock-Derived Composites Based on Biogenic Gold, Silver Chloride and Zinc Oxide Particles as Green Multifunctional Platforms for Biomedical Applications and Environmental Protection.

Green nanotechnology is a rapidly growing field linked to using the principles of green chemistry to design novel nanomaterials with great potential in environmental and health protection. In this work, metal and semiconducting particles (AuNPs, AgClNPs, ZnO, AuZnO, AgClZnO, and AuAgClZnO) were phytosynthesized through a "green" bottom-up approach, using burdock (Arctium lappa L.) aqueous extract. The morphological (SEM/TEM), structural (XRD, SAED), compositional (EDS), optical (UV-Vis absorption and FTIR spectroscopy), photocatalytic, and bio-properties of the prepared composites were analyzed. The particle size was determined by SEM/TEM and by DLS measurements. The phytoparticles presented high and moderate physical stability, evaluated by zeta potential measurements. The investigation of photocatalytic activity of these composites, using Rhodamine B solutions' degradation under solar light irradiation in the presence of prepared powders, showed different degradation efficiencies. Bioevaluation of the obtained composites revealed the antioxidant and antibacterial properties. The tricomponent system AuAgClZnO showed the best antioxidant activity for capturing ROS and ABTS•+ radicals, and the best biocidal action against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The "green" developed composites can be considered potential adjuvants in biomedical (antioxidant or biocidal agents) or environmental (as antimicrobial agents and catalysts for degradation of water pollutants) applications.

Current Trends and Prospects for Application of Green Synthesized Metal Nanoparticles in Cancer and COVID-19 Therapies.

Cancer and COVID-19 have been deemed as world health concerns due to the millions of lives that they have claimed over the years. Extensive efforts have been made to develop sophisticated, site-specific, and safe strategies that can effectively diagnose, prevent, manage, and treat these diseases. These strategies involve the implementation of metal nanoparticles and metal oxides such as gold, silver, iron oxide, titanium oxide, zinc oxide, and copper oxide, formulated through nanotechnology as alternative anticancer or antiviral therapeutics or drug delivery systems. This review provides a perspective on metal nanoparticles and their potential application in cancer and COVID-19 treatments. The data of published studies were critically analysed to expose the potential therapeutic relevance of green synthesized metal nanoparticles in cancer and COVID-19. Although various research reports highlight the great potential of metal and metal oxide nanoparticles as alternative nanotherapeutics, issues of nanotoxicity, complex methods of preparation, biodegradability, and clearance are lingering challenges for the successful clinical application of the NPs. Thus, future innovations include fabricating metal nanoparticles with eco-friendly materials, tailor making them with optimal therapeutics for specific disease targeting, and in vitro and in vivo evaluation of safety, therapeutic efficiency, pharmacokinetics, and biodistribution.

Fast one-pot microwave-assisted green synthesis of highly fluorescent plant-inspired S,N-self-doped carbon quantum dots as a sensitive probe for the antiviral drug nitazoxanide and hemoglobin

In this study, we report a one-pot, green, cost-efficient, and fast synthesis of plant-based sulfur and nitrogen self-co-doped carbon quantum dots (S,N-CQDs). By 4-min microwave treatment of onion and cabbage juices as renewable, cheap, and green carbon sources and self-passivation agents, blue emissive S,N-CQDs have been synthesized (λex/λem of 340/418 nm) with a fluorescence quantum yield of 15.2%. A full characterization of the natural biomass-derived quantum dots proved the self-doping with nitrogen and sulfur. The S,N-CQDs showed high efficiency as a fluorescence probe for sensitive determination of nitazoxanide (NTZ), that recently found wide applicability as a repurposed drug for COVID-19, over the concentration range of 0.25–50.0 μM with LOD of 0.07 μM. The nanoprobe has been successfully applied for NTZ determination in pharmaceutical samples with excellent % recovery of 98.14 ± 0.42. Furthermore, the S,N-CQDs proved excellent performance as a sensitive fluorescence nanoprobe for determination of hemoglobin (Hb) over the concentration range of 36.3–907.5 nM with a minimum detectability of 10.30 nM. The probe has been applied for the determination of Hb in blood samples showing excellent agreement with the results documented by a medical laboratory. The greenness of the developed probe has been positively investigated by different greenness metrics and software. The green character of the proposed analytical methods originates from the synthesis of S,N-CQDs from sustainable, widely available, and cheap plants via low energy/low cost microwave-assisted technique. Omission of organic solvents and harsh chemicals beside dependence on mix-and-read analytical approach corroborate the method greenness. The obtained results demonstrated the substantial potential of the synthesized green, safe, cheap, and sustainable S,N-CQDs for pharmaceutical and biological applications. © 2022 Elsevier B.V.

Green Synthesis of Copper Nanoparticles Using Strawberry Leaves and Study of Properties, Anti-cancer Action, and Activity Against Bacteria Isolated from Covid-19 Patients

Severe acute respiratory syndrome type 2 caused by coronavirus 2 is responsible for SARS that led to the emergence of coronavirus disease 2019 (COVID-19). Recent studies have demonstrated a high correlation between secondary bacterial infections and worse outcomes and death in COVID-19 patients. The extensive use of medicines during the last SARS-CoV epidemic led to an increase in the prevalence of multi-drug-resistant germs. Nanoparticles have important characteristics and applications in health, industry, and applied fields, etc. In medical fields, they curb and stop antibiotic-resistant diseases and pathogens. In this study, strawberry leaf extract was used to synthesize copper nanoparticles. The benefits of copper nanoparticles in inhibiting the growth of Pseudomonas aeruginosa and S. aureus bacteria isolated from COVID-19 patients' sputum were tested using the agar well diffusion method. P. aeruginosa and S. aureus bacteria play a significant part in the series of bacterial infections that arise with COVID-19 infection. (1 ml) of strawberry leaf extract was mixed with (50 ml) of copper chloride solution prepared at a concentration of 2 mM at room temperature. The mixture was blended for 7 h to produce copper nanoparticles with a concentration of 2 mM as a stock solution in an environment-friendly manner. The first indication of the production of copper nanoparticles was the increase in the color intensity of the mixture after 7 h. The nanoparticles were detected using UV spectrophotometers, and a scanning electron microscope SEM, XRD, FTIR, and UV-VIS spectral, which appeared at the absorbance of two absorptive peaks, namely: 299 and 804 nm. UV-VIS spectral examination was conducted after a month and was very intense. It also showed two absorbance peaks (300 and 805 nm) with increasing intensity. This is evidence of the insolubility of the nanomaterial and its stability over the month. The scanning electron microscopy results showed that the dimensions of the prepared copper nanoparticles ranged between (46.59 and 58.82 nm). The production of copper nanoparticles in this inexpensive and environmentally friendly biological way has given excellent results in inhibiting the growth of bacteria isolated from COVID-19 patients. The effectiveness of copper nanoparticles was tested against cancerous cells isolated from laryngeal carcinoma, called HeP-2, of a 60-year-old man. The concentration of 50% of the copper nanoparticle solution, which is equivalent to 0.5 mM, gave an inhibition rate of 44.081% in cell cultures. Its effect was compared with the sensitivity of the normal cell line of liver cells (WRL-68);the concentration of 50%, which is equivalent to 0.5 mM, gave an inhibition rate of 5.997% in cell cultures, which showed a good affinity for copper nanoparticles. From this, we conclude that the copper nanoparticles were more effective in inhibiting cancerous cell lines than the normal ones. © 2023 University of Kerbala.

Green Synthesis of Copper Nanoparticles by Using Plant Extracts and their Biomedical Applications – An Extensive Review

In recent years, the green synthesis of different metal nanoparticles has become a substan-tial technique for the synthesis of different essential nanoparticles and their potential applications in technological, industrial along with biomedical fields. Among the several essential nanoparticles, copper nanoparticles (CuNPs) have attracted enormous attention for their wide range of applications like the production of gas sensors, solar cells, high-temperature superconductors as well as drug delivery materials and catalysis owing to its distinctive optical, electrical, dielectric, imaging and catalytic, etc. properties. Herein, in this review, our aim is to find out the recent progress of synthesis, as well as different optical and structural characterizations of green, synthesized CuNPs along with their broad-spectrum biomedical applications, mainly antibacterial, antifungal, antiviral and anticancer as well as the future perspective of research trends in the green synthesis of CuNPs. CuNPs have been synthesized by different researchers using three methods, namely, physical, chemical, and biological. In this review, the eco-friendly, efficient and low cost different established biological/green synthesis methods of CuNPs using different plant extracts like leaves, flowers, fruits, seeds, latex, etc., as capping and reducing agents have been briefly discussed, along with reaction conditions together with their optical as well as structural analysis. Effects of different parameters on the green synthesis of CuNPs like the presence of phytochemicals and confirmation of phytochemicals, temperature, pH, etc., are eluci-dated. Studies of the antibacterial activity of biomolecules capped CuNPs by different researchers against both Gram-positive and Gram-negative bacterial strains along with minimum inhibitory concentration (MIC) values have been summarized. Furthermore, antifungal and antiviral effects of green synthesized CuNPs studied by different researchers are mentioned with minimum inhibitory concentration (MIC) values. The anticancer activity of green synthesized CuNPs against different cancer cells studied by different researchers is summarized with correlation sizes of CuNPs on anticancer activity. The review also focuses on in vivo applications of green synthesized CuNPs along with clinical trails. Furthermore, an emphasis is given to the effectiveness of CuNPs in combating COVID-19. © 2023 Bentham Science Publishers.

A benzimidazole scaffold as a promising inhibitor against SARS-CoV-2.

The manuscript reports the green-chemical synthesis of a new diindole-substituted benzimidazole compound, B1 through a straightforward route in coupling between indolyl-3-carboxaldehyde and o-phenylenediamine in water medium under the aerobic condition at 75 ºC. The single crystal X-ray structural analysis of B1 suggests that the disubstituted benzimidazole compound crystallizes in a monoclinic system and the indole groups exist in a perpendicular fashion with respect to benzimidazole moiety. The SARS-CoV-2 screening activity has been studied against 1 × 10e4 VeroE6 cells in a dose-dependent manner following Hoechst 33342 and nucleocapsid staining activity with respect to remdesivir. The compound exhibits 92.4% cell viability for 30 h and 35.1% inhibition against VeroE6 cells at non-cytotoxic concentration. Molecular docking studies predict high binding propensities of B1 with the main protease (Mpro) and non-structural (nsp2 and nsp7-nsp8) proteins of SARS-CoV-2 through a number of non-covalent interactions. Molecular dynamics (MD) simulation analysis for 100 ns confirms the formation of stable conformations of B1-docked proteins with significant changes of binding energy, attributing the potential inhibition properties of the synthetic benzimidazole scaffold against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Development of Cost-Effective, Ecofriendly Selenium Nanoparticle-Functionalized Cotton Fabric for Antimicrobial and Antibiofilm Activity

In the present study, selenium nanoparticles were synthesized in situ on alkali-activated cotton fabric using guava leaf extract as a reducing agent. The synthesis was monitored by a change in color of fabric from white to light brick red. The UV-DRS analysis confirms the coating of Se NPs on cotton. The XRD, FT-IR, and SEM-EDX characterization techniques were used to analyze the nanoparticles on cotton fabric. The peak at 788 cm−1 in FT-IR confirms the formation of Se NPs on cotton fabric. The XRD analysis confirms that the average crystallite size of as-prepared nanoparticle is ~17 nm. SEM-EDX analysis shows the successful coating of Se NPs on coated fabric. ICP-OES studies confirm 3.65 mg/g of selenium nanoparticles were present on the fabric. The Se-coated-30 showed a larger zone of inhibition against Gram-positive S. aureus (32 mm) compared to Gram-negative strains of E. coli (16 mm) and K. pneumoniae (26 mm). The fabric was also tested against the fungi C. glabrata (45 mm), C. tropicalis (35 mm), and C. albicans (35 mm) and results indicate it is more effective against fungal compared to bacterial strains. The coated fabric inhibits biofilm formation of C. albicans (99%), S. aureus (78%), and E. coli (58%). The results demonstrated excellent antibacterial, antifungal, and antibiofilm activities of the Se-coated-30. The prepared fabric has the potential to be used in medicinal applications and is both ecofriendly and cost effective.

Nanosponges: Advancement in Nanotherapeutics

The emergence of nanotechnology paves the way for improving disease therapy strategies. An investigation into the progression of the release of the medication targeting the specified predetermined location is a significant factor to consider. Due to the ability to advance existing products and to develop new products in a variety of applications, the nanotechnology industry is considered an evolving technology. Cyclodextrin-based porous nanoparticles or unique nano-sponges (NSs) which have recently been used in the pharmaceutical, biomedical, and cosmetic industries are the main elements of this growth. This superior technology can circumvent the defects of current techniques by its ability to attack and visualize tumour sites. A biodegradable and biocompatible feature along with a built-in high surface area resulting in enormous amounts of drug loading and biomimetic design, and the ability to control nanoparticles size are just a handful of good attractive attributes that find this technique as an overwhelming advantage in the field of nanomedicine. This review article is organized such that we first explored the unique features of these nanosponges and the diverse methods for synthesizing, followed by the drug loading and release principle and application based on drug delivery, targeting, boosting solubility of BCS Class II and IV drugs, others in biomedicine and more. Finally, the recent progress on the use of biomimetic nanosponge as a pandemic tool due to the SARS-CoV-2 virus briefly comes into line. Copyright © RJPT All right reserved.

A convenient synthesis, in silico study and crystal structure of novel sulfamidophosphonates: Interaction with SARS-CoV-2

A one-pot synthetic strategy was developed for the synthesis of novel sulfamidophosphonates via a three -component Kabachnik-Fields reaction of sulfanilamide, triethyl phosphite, and various aldehyde using ul-trasound irradiation. Seven organophosphorus derivatives were synthesized with high yields through this newly developed method. The target compounds were characterized by 1 H, 31 P, 13 C NMR, and IR. The molecular structure of 4a was obtained by X-ray diffraction on the monocrystal. Crystal belongs to the orthorhombic system with space groups Pbca. Insight into the binding mode of the synthesized com-pounds (ligand) into the binding sites of SARS-CoV2 (PDF code: 5R80 ) was provided by docking studies, performed with the help of Maestro 9.0 docking software.(c) 2022 Elsevier B.V. All rights reserved.

Green microwave synthesis of ZnO and CeO2 nanorods for infectious diseases control and biomedical applications.

Control of Infectious diseases such as; bacteria and viruses, has become a globally critical issue, since the appearance of COVID-19 virus in 2020. In addition to the microbial resistance of the currently available therapeutic drugs as well as, its prolonged side effects make its use is of health care concern. Green nanotechnology approach is a promising solution for controlling such infectious diseases and many biomedical purposes. In the present study, green synthesis approach based on microwave-assisted hydrothermal method is an innovative and environmentally friendly method for preparation of bioactive CeO2 and ZnO nanorod structured materials using Olea europaea (O. e.) leaf plant extract as a natural medicinal capping agent for controlling the shape and size of nano-products. The optical and structural analyses of the obtained nanorod-structures are characterized using; TEM, FTIR, XRD, SBET analyses and particle size analyzer. The green-synthesized ZnO and CeO2 nanorods display an average crystallite size of approximately 15 and 5 nm, respectively. The antimicrobial activity of ZnO and CeO2 nanorods compared with the traditional hydrothermal methods, was examined on six clinical pathogens including; (E. coli Serratia sp., S. aureus, Bacillus subtilis, Streptococcus mutant, and MRSA). The results indicated superior antimicrobial and anti-tumor activities towards hepatocellular carcinoma cell lines (IC50 = 117.24 and 103.50 µg mL-1 for ZnO and CeO2 and LD50 > 3000 mg kg-1). This demonstrates that the green microwave process is a promising approach for the synthesis of effective ZnO and CeO2 nanomaterials applied for many biomedical applications.

The Biosynthesized Zinc Oxide Nanoparticles' Antiviral Activity in Combination with Pelargonium zonale Extract against the Human Corona 229E Virus.

Almost one-third of all infectious diseases are caused by viruses, and these diseases account for nearly 20% of all deaths globally. It is becoming increasingly clear that highly contagious viral infections pose a significant threat to global health and economy around the world. The need for innovative, affordable, and safe antiviral therapies is a must. Zinc oxide nanoparticles are novel materials of low toxicity and low cost and are known for their antiviral activity. The genus Pelargonium was previously reported for its antiviral and antimicrobial activity. In this work, Pelargonium zonale leaf extract chemical profile was studied via high-performance liquid chromatography (HPLC) and was used for the biosynthesis of zinc oxide nanoparticles. Furthermore, the antiviral activity of the combination of P. zonale extract and the biosynthesized nanoparticles of ZnO against the human corona 229E virus was investigated. Results revealed that ZnONPs had been biosynthesized with an average particle size of about 5.5 nm and characterized with UV, FTIR, TEM, XRD, and SEM. The antiviral activity showed significant activity and differences among the tested samples in favor of the combination of P. zonale extract and ZnONPs (ZnONPs/Ex). The lowest IC50, 2.028 µg/mL, and the highest SI, 68.4 of ZnONPs/Ex, assert the highest antiviral activity of the combination against human coronavirus (229E).

Fast one-pot microwave-assisted green synthesis of highly fluorescent plant-inspired S,N-self-doped carbon quantum dots as a sensitive probe for the antiviral drug nitazoxanide and hemoglobin

In this study, we report a one-pot, green, cost-efficient, and fast synthesis of plant-based sulfur and nitrogen self-co-doped carbon quantum dots (S,N-CQDs). By four-minutes microwave treatment of onion and cabbage juices as renewable, cheap, and green carbon sources and self-passivation agents, blue emissive S,N-CQDs have been synthesized (λex/λem of 340/418 nm) with a fluorescence quantum yield of 15.2%. A full characterization of the natural biomass-derived quantum dots proved the self-doping with nitrogen and sulfur. The S,N-CQDs showed high efficiency as a fluorescence probe for sensitive determination of nitazoxanide (NTZ), that recently found wide applicability as repurposed drug for COVID-19, over the concentration range of 0.25–50.0 μM with LOD of 0.07 μM. The nanoprobe has been successfully applied for NTZ determination in pharmaceutical samples with excellent % recovery of 98.14 ± 0.42. Furthermore, the S,N-CQDs proved excellent performance as a sensitive fluorescence nanoprobe for determination of hemoglobin (Hb) over the concentration range of 36.3–907.5 nM with a minimum detectability of 10.3 nM. The probe has been applied for the determination of Hb in blood samples showing excellent agreement with the results documented by a medical laboratory. The greenness of the developed probe has been positively investigated by different greenness metrics and software. The green character of the proposed analytical methods originates from the synthesis of S,N-CQDs from sustainable, widely available, and cheap plants via low energy/low cost microwave-assisted technique. Omission of organic solvents and harsh chemicals beside dependence on mix-and-read analytical approach corroborate the method greenness. The obtained results demonstrated the substantial potential of the synthesized green, safe, cheap, and sustainable S,N-CQDs for pharmaceutical and biological applications.

L-Proline Catalyzed Knoevenagel Condensation of Aldehydes with Active Methylene Compounds and Their Molecular Modeling Studies for Anti-SARS CoV-2 Potentials

Introduction: An efficient one-pot synthesis of 2-alkylidene/arylidene derivatives was reported from active methylene compounds such as malononitrile/ethyl cyanoacetate/5-methyl-2,4dihydro-3H-pyrazol-3-one and aldehydes in the presence of 10 mol% of L-proline (ethanol at room temperature). Methods: All derivatives were obtained in good to excellent yields. The structures of the synthesized compounds were confirmed from their FTIR (Fourier-transform infrared spectroscopy),1H-NMR (Proton nuclear magnetic resonance), and mass spectroscopy. The importance of these compounds is predicted from their SAR (structure-activity relationship) study. Moreover, these newer compounds were further docked into various therapeutic targets of the SARS-CoV-2 (severe acute respiratory syndromerelated coronavirus) virus. Results: Results from our molecular docking suggest that these compounds have good inhibitory properties on the SARS-CoV-2 virus. Conclusion: L-proline (bifunctional organic catalyst) is found to be the best catalyst for the synthesis of different condensed products from active methylene compounds and aldehydes. © 2022 Bentham Science Publishers.

Ag2O Nanoparticles as a Candidate for Antimicrobial Compounds of the New Generation.

Antibiotic resistance in microorganisms is an important problem of modern medicine which can be solved by searching for antimicrobial preparations of the new generation. Nanoparticles (NPs) of metals and their oxides are the most promising candidates for the role of such preparations. In the last few years, the number of studies devoted to the antimicrobial properties of silver oxide NPs have been actively growing. Although the total number of such studies is still not very high, it is quickly increasing. Advantages of silver oxide NPs are the relative easiness of production, low cost, high antibacterial and antifungal activities and low cytotoxicity to eukaryotic cells. This review intends to provide readers with the latest information about the antimicrobial properties of silver oxide NPs: sensitive organisms, mechanisms of action on microorganisms and further prospects for improving the antimicrobial properties.

Quantification of Spent Coffee Ground Extracts by Roast and Brew Method, and Their Utility in a Green Synthesis of Gold and Silver Nanoparticles.

Nanotechnology has become increasingly important in modern society, and nanoparticles are routinely used in many areas of technology, industry, and commercial products. Many species of nanoparticle (NP) are typically synthesized using toxic or hazardous chemicals, making these methods less environmentally friendly. Consequently, there has been growing interest in green synthesis methods, which avoid unnecessary exposure to toxic chemicals and reduce harmful waste. Synthesis methods which utilize food waste products are particularly attractive because they add value and a secondary use for material which would otherwise be disposed of. Here, we show that spent coffee grounds (SCGs) that have already been used once in coffee brewing can be easily used to synthesize gold and silver NPs. SCGs derived from medium and dark roasts of the same bean source were acquired after brewing coffee by hot brew, cold brew, and espresso techniques. The total antioxidant activity (TAC) and total caffeoylquinic acid (CQA) of the aqueous SCG extracts were investigated, showing that hot brew SCGs had the highest CQA and TAC levels, while espresso SCGs had the lowest. SCG extract proved effective as a reducing agent in synthesizing gold and silver NPs regardless of roast or initial brew method.

TiO2/core-shell structured carbon support materials derived from hydrothermal carbonization of waste masks biomass: a green photocatalyst

Surgical masks have become mandatory to protect against the COVID-19 epidemic. For this reason, the amount of waste masks has also reached severe dimensions. Turning these waste masks into functional materials (MC) in a green synthesis method is critical. In this study, carbon material from waste masks was synthesized by the hydrothermal carbonization method (HTC) and was used to increase the photocatalytic activity of TiO2. In addition, TiO2 nanoparticles were successfully synthesized by the solvothermal method. Thermo-gravimetric analysis (TGA), scanning-electron microscope(SEM), x-ray diffraction (XRD), Fourier transform- infrared spectroscopy (FT-IR), energy dispersive x-ray(EDX), transmission-electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), electrochemical-impedance spectroscopy (EIS) and Brunauer–Emmett–Teller (BET) analyzes were performed to illuminate the photocatalytic properties of the MC-TiO2 photocatalyst. In this sense, the functionality of the shell-core skeleton-based new generation carbon material was also investigated. The photocatalytic activity of the green type of photocatalyst was detected by comparing methylene blue (MB) and phenol photodegradation rates. In photocatalytic degradation experiments, both UV-A effect and visible light effect were examined. New type of photocatalyst an exhibited excellent photocatalytic effect. Superior photodegradation capacity may be referred as to the core-shell composition and functional groups of the effective carbon support material synthesized by the HTC method. In particular, the photocatalytic effect of the novel carbon support material is discussed in-depth with the proposed mechanism. With the present study, we aimed to bring a green perspective to the photocatalytic studies in the literature.

Green synthesis of ZrO2 nanoparticles and nanocomposites for biomedical and environmental applications: a review.

Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of ZrO2 nanoparticles and their nanocomposites using compounds from bacteria, fungi, microalgae, and plants. For instance, bacteria, microalgae, and fungi secret bioactive metabolites such as fucoidans, digestive enzymes, and proteins, while plant tissues are rich in reducing sugars, polyphenols, flavonoids, saponins, and amino acids. These compounds allow reducing, capping, chelating, and stabilizing during the transformation of Zr4+ into ZrO2 nanoparticles. Green ZrO2 nanoparticles display unique properties such as a nanoscale size of 5-50 nm, diverse morphologies, e.g. nanospheres, nanorods and nanochains, and wide bandgap energy of 3.7-5.5 eV. Their high stability and biocompatibility are suitable biomedical and environmental applications, such as pathogen and cancer inactivation, and pollutant removal. Emerging applications of green ZrO2-based nanocomposites include water treatment, catalytic reduction, nanoelectronic devices, and anti-biofilms.

Green Synthesis of Silver Nanoparticles Coated by Water Soluble Chitosan and Its Potency as Non-Alcoholic Hand Sanitizer Formulation.

The synthesis of silver nanoparticles using plant extracts, widely known as a green synthesis method, has been extensively studied. Nanoparticles produced through this method have applications as antibacterial agents. Bacterial and viral infection can be prevented by use of antibacterial agents such as soap, disinfectants, and hand sanitizer. Silver nanoparticles represent promising hand sanitizer ingredients due to their antibacterial activity and can enable reduced use of alcohol and triclosan. This study employed silver nanoparticles synthesized using Kepok banana peel extract (Musa paradisiaca L.). Nanoparticle effectiveness as a hand sanitizer can be enhanced by coating with a biocompatible polymer such as chitosan. The characterization of silver nanoparticles was conducted using UV-Vis, with an obtained peak at 434.5 nm. SEM-EDX analysis indicated nanoparticles with a spherical morphology. Silver nanoparticles coated with chitosan were characterized through FTIR to verify the attached functional groups. Gel hand sanitizers were produced using silver nanoparticles coated with different chitosan concentrations. Several tests were undertaken to determine the gel characteristics, including pH, syneresis, and antibacterial activity. Syneresis leads to unstable gels, but was found to be inhibited by adding chitosan at a concentration of 2%. Antibacterial activity was found to increase with increase in chitosan concentration.