Alginate Modified Magnetic Polypyrrole Nanocomposite for the Adsorptive Removal of Heavy Metal.

The presence of heavy metals with high acute toxicity in wastewater poses a substantial risk to both the environment and human health. To address this issue, we developed a nanocomposite of alginate-encapsulated polypyrrole (PPy) decorated with α-Fe2O3 nanoparticles (Alg@Mag/PPy NCs), fabricated for the removal of mercury(II) from synthetic wastewater. In the adsorption experiments, various parameters were examined to identify the ideal conditions. These parameters included temperature (ranging from 298 to 323 K), initial pH levels (ranging from two to nine), interaction time, amount of adsorbent (from 8 to 80 mg/40 mL), and initial concentrations (from 10 to 200 mg/L). The results of these studies demonstrated that the removal efficiency of mercury(II) was obtained to be 95.58% at the optimum pH of 7 and a temperature of 303 K. The analysis of adsorption kinetics demonstrated that the removal of mercury(II) adhered closely to the pseudo-second-order model. Additionally, it displayed a three-stage intraparticle diffusion model throughout the entire adsorption process. The Langmuir model most accurately represented equilibrium data. The Alg@Mag/PPy NCs exhibited an estimated maximum adsorption capacity of 213.72 mg/g at 303 K, surpassing the capacities of most of the other polymer-based adsorbents previously reported. The thermodynamic analysis indicates that the removal of mercury(II) from the Alg@Mag/PPy NCs was endothermic and spontaneous in nature. In summary, this study suggests that Alg@Mag/PPy NCs could serve as a promising choice for confiscating toxic heavy metal ions from wastewater through adsorption.

State-of-the-art advances in nanocomposite and bio-nanocomposite polymeric materials: A comprehensive review.

The modern eco-friendly materials used in research and innovation today consist of nanocomposites and bio-nanocomposite polymers. Their unique composite properties make them suitable for various industrial, medicinal, and energy applications. Bio-nanocomposite polymers are made of biopolymer matrices that have nanofillers dispersed throughout them. There are several types of fillers that can be added to polymers to enhance their quality, such as cellulose-based fillers, clay nanomaterials, carbon black, talc, carbon quantum dots, and many others. Biopolymer-based nanocomposites are considered a superior alternative to traditional materials as they reduce reliance on fossil fuels and promote the use of renewable resources. This review covers the current state-of-the-art in nanocomposite and bio-nanocomposite materials, focusing on ways to improve their features and the various applications they can be used for. The review article also investigates the utilization of diverse nanocomposites as a viable approach for developing bio-nanocomposites. It delves into the underlying principles that govern the synthesis of these materials and explores their prospective applications in the biomedical field, food packaging, sensing (Immunosensors), and energy storage devices. Lastly, the review discusses the future outlook and current challenges of these materials, with a focus on sustainability.

Ingestion and effects of green synthesized cadmium sulphide nanoparticle on Spodoptera Litura as an insecticidal and their antimicrobial and anticancer activities.

The current study investigated the multifunctional properties of Cadmium Sulphide Nanoparticles synthesized using a green synthesis method (CdS NPs) using a green feedstock, Nopal Cactus fruit extract. The biological activities of the CdS NPs were thoroughly investigated, including their insecticidal, antibacterial, and anticancer activities. The different concentrations (0.005-0.04%) of CdS NPs were fed to the larvae of Spodoptera litura, and their ingestion effects were observed on the different biological, biochemical, and oxidative stress markers. There are significant dose-dependent changes in the biochemical parameters like superoxide dismutase (SOD), Catalase (CAT), Glutathione-S-transferase (GST), and MDA level as a marker of lipid peroxidation in the treated larvae were studied. In the highest concentration (0.04%), significant larval mortality (46.66%), malformation (pupae and adult) (27.78%), inhibition of adult emergence (43.87%), as well as reduced fecundity (25.28%), and fertility (22.74%) as compared to control was observed. CdS NPs have been investigated for antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus bacterial strains. In vitro anticancer activities were carried out to decrease the viability of the Pancreatic cancer cell line. The cells showed 18% and 12% viability at a 200 µg/ml concentration when incubated with CdS NPs for 24 and 48 h, respectively, confirming its potent anticancer property. The lack of cytotoxicity against the (RBC) endorses the biocompatible nature of synthesized CdS NPs. It was observed that green synthesized CdS NPs could be used as a promising insecticidal, antibacterial, and anticancer agent.

Novel ZrO2-glycine nanocomposite as eco-friendly high temperature corrosion inhibitor for mild steel in hydrochloric acid solution.

We report the green synthesis of novel ZrO2-Glycine nanocomposite referred to as ZrO2-Gly NC followed by its characterization using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, SEM/EDX, and transmission electron microscopy (TEM) techniques. Further, the inhibition effect of the varying concentration of ZrO2-Gly NC on the corrosion of mild steel (MS) in 1 M HCl was investigated by weight loss and electrochemical measurements at 40-80 °C. The percentage inhibition efficacy of NC increased with the increase of concentration and temperature and reached about 81.01% at 500 ppm at 70 °C which decreased at 80 °C and exhibited 73.5% inhibition efficiencies. According to the polarization measurements, the investigated ZrO2-Gly NC works as a mixed-type inhibitor with predominantly inhibiting cathodic reaction. Also, the adsorption isotherm analysis indicated that the adsorption was spontaneous and followed the Langmuir adsorption isotherm. Furthermore, the contact angle measurement revealed the water-repelling property of the investigated inhibitor. The surface morphological study via SEM-EDS micrograph affirmed the appearance of a smooth surface in presence of inhibited media suggesting the formation of protective film by the adsorption of ZrO2-Gly NC on the surface of the MS even at higher temperature.

Immobilization of GOx Enzyme on SiO2-Coated Ni-Co Ferrite Nanocomposites as Magnetic Support and Their Antimicrobial and Photocatalytic Activities.

The present study used a sol-gel auto-combustion approach to make silica (SiO2)-coated Ni-Co ferrite nanocomposites that would be used as a platform for enzyme immobilization. Using glutaraldehyde as a coupling agent, glucose oxidase (GOx) was covalently immobilized on this magnetic substrate. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and fourier transform infrared spectroscopy (FTIR) was used to determine the structural analysis and morphology of Ni-Co ferrite/SiO2 nanocomposites. FTIR spectra confirmed the binding of GOx to Ni-Co ferrite/SiO2 nanocomposites, with a loading efficiency of around 85%. At alkaline pH and higher temperature, the immobilized GOx enzyme exhibited increased catalytic activity. After 10 times of reuses, it still had 69% catalytic activity. Overall, the immobilized GOx displayed higher operational stability than the free enzyme under severe circumstances and was easily recovered by magnetic separation. With increased doping concentration of the nanocomposites, the photocatalytic activity was assessed using a degradation process in the presence of methylene blue dye under UV light irradiation, which revealed that the surface area of the nanocomposites with increased doping concentration played a significant role in improving photocatalytic activity. The antibacterial activity of Ni-Co ferrite/SiO2 nanocomposites was assessed using the agar well diffusion method against Escherichia coli, a gram-negative bacteria (ATCC 25922). Consequently, it was revealed that doping of Ni2+ and Co2+ in Fe2O4/SiO2 nanocomposites at varied concentrations improved their antibacterial properties.

Tailoring a robust nanozyme formulation based on surfactant stabilized lipase immobilized onto newly fabricated magnetic silica anchored graphene nanocomposite: Aggrandized stability and application.

Candida rugosa lipase (CRL) was treated with surfactants and immobilized onto the novel formulated magnetic graphene anchored silica nanocomposite (Fe3O4/SiO2/Gr NC). For this purpose, the surface of lipase was initially coated with Triton-X 100 and cetyltrimethylammonium bromide surfactants, to stabilize enzyme in its open form and was then adsorbed onto aminated Fe3O4/SiO2/Gr NC. Glutaraldehyde (GA) was then utilized to cross-link the adsorbed lipase onto the NC. The fabricated NC and conjugated lipase was characterized by various techniques such as FT-IR, XRD, TGA, SEM, TEM, CLSM, CD and Fluorescence spectroscopy. The magnetic character of the as-synthesized NC was verified by AGM investigation. CD and fluorescence spectroscopic analysis demonstrated slight structural rearrangements in lipase upon conjugation. The surfactant stabilized immobilized lipase demonstrated significantly enhanced thermostability, tolerance to various metal ions and inhibitors. The immobilization yield obtained owing to lipase interfacial activation by Triton X 100 and CTAB was remarkably enhanced by 6-folds and 3-folds, respectively which were remarkably higher in comparison to free immobilized lipase. The fabricated nanobiocatalysts were employed to synthesise green apple flavour ester, ethyl valerate via esterification reaction. Triton X 100 stabilized immobilized lipase was a better performer in yielding green apple flavour ester, demonstrating about 90% ester yield as compared to 78% yield obtained by CTAB stabilized immobilized lipase preparation. The obtained outcomes suggested that enzyme structure was stabilized by the GA treatment if executed in the absence or in the presence of detergent, and that, in the company of detergent, a conformation of the lipase with the exposed active center to the medium provided an aggrandized catalytic performance.

Enhanced Insecticidal Activity of Thiamethoxam by Zinc Oxide Nanoparticles: A Novel Nanotechnology Approach for Pest Control.

Indiscriminate and unregulated application of pesticides produces deleterious effect in various groups of organisms including humans and the environment. To solve these issues, it has been reported that the residue-free green nanocomposite synergistically enhances the pesticide efficacy. In this study, ZnO nanoparticles (NPs) with a thiamethoxam nanocomposite were synthesized and we investigated their synergistic effect on 4th instar larvae of Spodoptera litura (Lepidoptera: Noctuidae). These larvae were allowed to feed on the composite of ZnO NPs with thiamethoxam (10-90 mg/L) and thiamethoxam-impregnated castor leaves. Observations showed an increased larval mortality (27% increased mortality), a malformation in pupae and adults, overdue emergence, and reduced fecundity and fertility. A significant dose-dependent variation in the biochemical parameters such as superoxide dismutase (SOD), glutathione-S-transferase (GST), and thiobarbituric acid-reactive substances (TBARS) in the treated larvae was also observed. A decline of 72.42 and 33.82% in SOD and GST activity ,respectively, was observed at higher concentration as compared to the control. On the contrary, it enhanced the TBARS level up to 56.7%. The synthesized nanocomposite was characterized by different biophysical techniques such as X-ray diffraction (average crystalline size 34 nm), scanning electron microscopy, transmission electron microscopy (average particle size 30 nm), and Fourier transform infrared spectroscopy (Zn-O stretching peaks at 432 cm-1 and 503 cm-1). The observation of the present study suggests that ZnO NPs pave the way for developing cost-effective, eco-friendly, and capable nanomaterial for its applications in the field of biological sciences.

Cysteine-silver-gold Nanocomposite as potential stable green corrosion inhibitor for mild steel under acidic condition.

Cysteine based silver-gold nanocomposite (Cys/Ag-Au NCz) was synthesized, this was followed by its characterization using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Ultraviolet-visible spectroscopy (UV-Vis), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX), Thermogravimetric analysis (TGA) and Transmission electron microscopy (TEM). Cys/Ag-Au NCz was studied as novel green corrosion inhibitor for mild steel in 1M HCl solution at varying concentration and temperature using gravimetric, Potentiodynamic polarization (PDP), Electrochemical impedance spectroscopy (EIS), SEM, EDAX and FTIR. Weight loss, PDP and EIS studies confirmed Cys/Ag-Au NCz as efficient corrosion inhibitor at moderately low concentration. The maximum inhibition efficiency of 96 % was observed at 303 K at 300 ppm. Cys/Ag-Au NCz acted by affecting both anodic and cathodic processes and its adsorption on steel surface followed the Langmuir adsorption isotherm. EIS data displayed the existence of protective film at mild steel/solution interface in Cys/Ag-Au NCz inhibited system. SEM micrograph in presence of Cys/Ag-Au NCz inhibited acid solution displayed better morphology as compared to blank solution. The UV-Vis and FTIR data indicates good interaction between the Cys/Ag-Au NCz and steel surface.

Effectiveness of reactive oxygen species generated from rGO/CdS QD heterostructure for photodegradation and disinfection of pollutants in waste water.

The present study investigates the role of reactive oxygen species (ROS) generated on surface of nanophotocatalyst in wastewater treatment discharged from exponentially growing industries. A facile synthetic route is presented to produce reduced graphene oxide/CdS quantum dot (rGO/CdS QD) heterostructure by monowave-assisted solvothermal method where room temperature ionic liquid 1-ethyl-3-methylimidazolium thiocyanate serves as a "green" precursor. The prepared photocatalyst was tested for: (1) photodegradation performance against various cationic dyes, anionic dyes, and antibiotics as model organic water pollutants; and (2) disinfection performance against gram-positive S. aureus and gram-negative E. coli bacterial strains as pathogenic water pollutants. The negative surface charge of rGO/CdS QD precisely attracted the cationic dye molecules to its surface and degraded the dyes at a higher rate. Moreover, excellent antibacterial activity of rGO/CdS QD were observed against S. aureus and E. coli with a minimum inhibitory concentration of 16 µg ml-1 and 32 µg ml-1, respectively. A plausible mechanism of the photocatalytic activity suggested that ROS with strong oxidizing ability reacts with the organic pollutants to mineralize them into CO2, H2O or some other small molecules, and reacts with pathogens to damage the macromolecules like proteins, lipids, DNA, etc in the bacterial cells. Among all the surface generated ROS, hydroxyl radicals was found to be the main contributor in the photodegradation and disinfection mechanism.

In Vitro and in Vivo Antimicrobial Evaluation of Graphene-Polyindole (Gr@PIn) Nanocomposite against Methicillin-Resistant Staphylococcus aureus Pathogen.

Nowadays, the infection caused by the methicillin-resistant Staphylococcus aureus (MRSA) and countless different types of bacterial infection cause the death of millions of people worldwide. Thereby, several strategies have explored for the advancement of better and active antimicrobial agents; one of these lies in the form of two-dimensional carbon-based nanocomposites. Herein, we demonstrate the synthesis of the graphene-polyindole (Gr@PIn) nanocomposite and polyindole (PIn) and significantly enhance the proficiency against MRSA strains which are immune to most antibiotics. The synthesized Gr@PIn and PIn have been characterized by the various biophysical techniques, especially X-ray diffraction (XRD), electron microscopy [scanning electron microscopy (SEM) and transmission electron microscopy (TEM)], Fourier transform infrared, Raman, UV-vis spectroscopy, and thermogravimetric analysis. Electron microscopic investigations unveiled the disintegration of bacterial cell wall upon interaction with Gr@PIn. Significantly, the Gr@PIn found to be very potent in the eradication of the MRSA strain with minimal toxicity to the mammalian cells. Assessment of the antibacterial mechanism revealed that the Gr@PIn adhered toward the bacterial surface, irreversibly interrupted the membrane layer structure of the bacteria, eventually penetrated cells, and efficiently impeded protein activity, which inherently turns into bacterial apoptosis in vitro. Moreover, last, the synthesized Gr@PIn efficiently treated the S. aureus-mediated experimental skin infection in BALB/c mice as well. This work magnifies our comprehending antibacterial mechanism of nonmetallic graphene-based PIn nanocomposite and provides the support to activity anticipation.

Co-precipitation synthesis and characterization of Co doped SnO2 NPs, HSA interaction via various spectroscopic techniques and their antimicrobial and photocatalytic activities.

Sn1-xCoxO2 (x=0.00, 0.01, 0.03, 0.05) nanoparticles (NPs) of average size ∼30-40nm were synthesized by co-precipitation method. The interaction of Co doped SnO2 NPs with human serum albumin (HSA) and their photocatalytic and antimicrobial properties were studied. The structural analysis and morphology of Co doped SnO2 NPs were analysed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FT-IR). Besides the structural and morphological analysis, the interaction of Co doped SnO2 NPs with HSA were studied by UV-vis, Circular dichroism (CD) and fluorescence spectroscopy. Fluorescence quenching results suggest that Co doped SnO2 NPs interact with an HSA molecule through static mechanism. CD indicates that α-helicity of HSA increases due to the interaction of Co doped SnO2 NPs. The photocatalytic activities of the NPs with increased doping concentration were evaluated through a degradation process in the presence of methylene-blue (MB) dye under UV light irradiation, which exhibited that the surface area of NPs with increased doping concentration plays a major role in improving the photocatalytic activity. The antimicrobial effect of undoped and Co-doped SnO2 NPs was determined using agar-well diffusion method and analyzed against gram-positive bacteria (Bacillus Cereus MC 2434). In our results, we have found that as the doping concentration increases into NPs, zone of inhibition increases, which could be ascribed to the production of ROS and large surface area of the NPs.

Kinetic Study on Mutagenic Chemical Degradation through Three Pot Synthesiszed Graphene@ZnO Nanocomposite.

The study was taken up with the objective to synthesize graphene-zinc oxide nano particles (NPs) nanocomposite (Gr@ZnO-Nc) via In-situ synthesis method. The structural, optical, thermal, electrical and photocatalytic properties of the synthesized Gr@ZnO-Nc were studied. The characterization data confirmed that the ZnO NPs were successfully incorporated into the graphene sheets. Further, TGA/DTA results exhibited an enhanced thermal stability of the Gr@ZnO-Nc compared with the graphene. The Gr@ZnO-Nc, graphene sheets were uniformly wrapped by ZnO NPs, which can protect graphene and delay their oxidation in air. The synthesized Gr@ZnO-Nc was used for the efficient photodegradation of a carcinogenic methyl orange (MO) dye. The results exhibited promising photodegradation of the MO dye under UV light irradiation through the production of reactive oxygen species (ROS). The promising effect of Gr@ZnO-Nc on the photodegradation properties was conferred by the large surface area which increased adsorption capacity, and the strong electron transfer ability. Thus, it is encouraging to conclude that the synthesized Gr@ZnO-Nc has environmental significance with its utility in remediation in the hazardous MO dye.

Anthelmintic Effect of Biocompatible Zinc Oxide Nanoparticles (ZnO NPs) on Gigantocotyle explanatum, a Neglected Parasite of Indian Water Buffalo.

Helminth parasites of veterinary importance cause huge revenue losses to agrarian economy worldwide. With the emergence of drug resistance against the current formulations, there is a need to focus on the alternative approaches in order to control this menace. In the present study, biocompatible zinc oxide nanoparticles (ZnO NPs) were used to see their in vitro effect on the biliary amphistomes, Gigantocotyle explanatum, infecting Bubalus bubalis because these nanoparticles are involved in generation of free radicals that induce oxidative stress, resulting in disruption of cellular machinery. The ZnO NPs were synthesized by using egg albumin as a biotemplate and subsequently characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction and Spectrophotometrical, which showed that ZnO NPs were highly purified wurtzite type polycrystals, with a mean size of 16.7 nm. When the parasites were treated with lower concentrations (0.004% and 0.008%) of the ZnO NPs, the worms mounted a protective response by stimulating the antioxidant system but the treatment of G. explanatum with 0.012% ZnO NPs produced significant inhibition of the antioxidant enzymes like superoxide dismutase (SOD) (p< 0.05) and glutathione S- transferase (GST) (p<0.01), while the level of malondialdehyde (MDA), a lipid peroxidation marker, was significantly (p< 0.01) elevated. SEM and histopathology revealed pronounced tegumental damage showing the disruption of surface papillae and the annulations, particularly in the posterior region near acetabulum. The under expression of a number of polypeptides, loss of worm motility in a time dependent manner, further reflect strong anthelmintic potential of ZnO NPs. It can be concluded that the anthelmintic effect might be due to the production of reactive oxygen species that target a variety of macromolecules such as nucleic acid, protein and lipids which are involved in different cellular processes.

Synthesis and characterization of structural, optical, thermal and dielectric properties of polyaniline/CoFe2O4 nanocomposites with special reference to photocatalytic activity.

In this study we have synthesized polyaniline/CoFe2O4 nanocomposites (PANI@CFs) by in situ polymerization method with different amounts of the CoFe2O4 nanoparticles NPs (CF-NPs) (0.5 g and 1.0 g). The structural optical, thermal and dielectric properties of the as synthesized PANI@CFs were studied. The XRD analysis ensures that CF-NPs have a single phase spinel structure. The XRD and EDAX results confirmed that the CF-NPs were successfully incorporated in the PANI matrix. The crystalline size analysis revealed that the size increased with increasing CF-NPs amount in the PANI@CFs, because of the aggregation effect. TGA exhibited an enhanced thermal stability of the PANI@CFs as compare with PANI owing to the strong interaction between the CF-NPs and polymer matrix. The energy band gaps as calculated through the Tauc relation were found to be gradually higher with the increasing the amount of CF-NPs in PANI@CFs. The dielectric constants (ε', ε″), dielectric loss (tanδ) and AC conductivity (σac) were studied as the function of frequency and composition, which have been explained by 'Maxwell Wagner Model'. The high dielectric constant and ac conductivity were observed of PANI@CFs than PANI. Moreover, PANI@CF 1:2 exhibited the promising photocatalytic activity for the photo-decoloration of the methyl orange (MO) dye under UV light irradiation. Results also showed protection of photo-decoloration of the MO dye by the disodium ethylenediaminetetraacetate dehydrate (EDTA-Na2; C10H14N2Na2O8·2H2O) (hole scavenger) and tert-butyl alcohol (C4H10O) (radical scavenger) clearly suggested the implication of reactive oxygen species (ROS) in the photocatalytic activity of PANI@CF 1:2. It is encouraging to conclude that PANI@CF bears the potential of its applications in photocatalysis.