Catunaregum spinosa capped Ag NPs and its photocatalytic application against amaranth toxic azo dye

Garlic capped silver nanoparticles for rapid detection of cholesterol

A fluorescent biosensor based on garlic (Allium sativum L.) capped Ag nanoparticles (G-Ag NPs) has been synthesized for cholesterol detection. Pristine Ag NPs and G-Ag NPs were synthesized through the chemical reduction process. The effect of different capping agents such as 3-aminopropyltriethoxysilane (APTS), glutathione, 8-hydroxyquinoline, garlic/APTS, garlic/glutathione, and garlic/8-hydroxyquinoline on Ag NPs was evaluated. These NPs were characterized using Fourier transform infrared (FTIR), energy-dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), X-Ray diffraction (XRD), UV-visible spectra, and Zeta potential. The HRTEM micrographs illustrated that Ag NPs with particles size ranging from 2.98 to 14.34 nm were aggregated. G-Ag NPs images showed uniformly distributed spherical particles with particles size from 4.52 to 12.8 nm. The reduction in the plasmonic bands of Ag NPs and G-Ag NPs occurred by 96.4% and 11.7%, respectively after 12 months. The developed sensor for cholesterol based on the fluorescence enhancement had a linear response in a concentration range of 0.4-5.17 mM with a sensitivity of 4.36 Mm^-1 and a limit of detection of 0.186 mM. The high selectivity toward cholesterol in presence of different interferes such as glucose, cysteine, glycine, urea, sucrose, nickel, and copper, and their mixture was evaluated. The applicability of this developed sensor for real serum samples was detected with a recovery percentage from 99.1 to 101.3%. Repeatability and reproducibility experiments displayed relative standard deviations (RSD) of 0.88% and 0.62%, respectively.

CuO Nanorods Immobilized Agar-Alginate Biopolymer: A Green Functional Material for Photocatalytic Degradation of Amaranth Dye

The contamination of water is increasing day by day due to the increase of urbanization and population. Textile industries contribute to this by discarding their waste directly into water streams without proper treatment. A recent study explores the treatment potential of copper oxide nanorods (CuO NRs) synthesized on a green basis in the presence of a biopolymer matrix of agar (AA) and alginate (Alg), in terms of cost effectiveness and environmental impact. The synthesized bio nanocomposite (BNC) was characterized by using different instrumental techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultra-violet spectroscopy (UV-Vis), scanning electron microscopy-energy dispersive X-ray-elemental analysis (SEM-EDX), transmission electron microscopy (TEM), selected area diffraction pattern (SAED) and X-ray photoelectron spectroscopy (XPS). The optical studies revealed that immobilization of CuO NRs with Alg-Agar biopolymer blend resulted in an increase in light absorption capacity by decreasing the energy bandgap from 2.53 eV to 2.37 eV. The bio nanocomposite was utilized as a photocatalyst for the degradation of amaranth (AN) dye from an aquatic environment under visible light irradiation. A statistical tool known as central composite design (CCD) associated with response surface methodology (RSM) was taken into consideration to evaluate the optimized values of process variables and their synergistic effect on photocatalytic efficiency. The optimized values of process variables were found to be irradiation time (45 min), AN concentration (80 ppm), catalyst dose (20 mg), and pH (4), resulting in 95.69% of dye degradation at 95% confidence level with desirability level 1. The rate of AN degradation was best defined by pseudo-first-order reaction based on the correlation coefficient value (R2 = 0.99) suggesting the establishment of adsorption-desorption equilibrium initially at the catalyst surface then photogenerated ^•O₂^- radicals interacting with AN molecule to mineralize them into small non-toxic entities like CO₂, H₂O. The material used has high efficiency and stability in photocatalytic degradation experiments up to four cycles of reusability.

Biosorption study of amaranth dye removal using Terminalia chebula shell, Peltophorum pterocarpum leaf and Psidium guajava bark

Amaranth dye (AD) is trisodium (4E)-3-oxo-4-[(4-sulfonato-1- naphthyl) hydrazono] naphthalene-2, 7-disulfonate and anionic in nature. In the present investigation, waste biomasses such as Terminalia chebula shell (TCS), Peltophorum pterocarpum leaf (PPL) and Psidium guajava bark (PGB) are explored as biosorbents for the first time toward the removal of AD from aqueous solution in a batch method. Influence of biosorption parameters such as pH, initial concentration of AD, biosorbents (TCS, PPL, PGB) dosage, temperature and contact time was studied. Biosorption equilibrium data was analyzed using two parameter isotherms. The kinetics of the biosorption process was analyzed using different models to understand the rate-determining step. The results of the biosorption experiment and modeling investigation illustrated that the pseudo-second-order rate equation fits the experimental data and further the experimental results showed Langmuir isotherm fitted well the biosorption equilibrium data. TCS showed more efficiency toward the removal of AD than PPL and PGB. The value of enthalpy for TCS is 1.527 kJ/mol suggests that the AD removal process is endothermic. The positive value of entropy is 6.429 J/mol K indicates that the particle is randomly disordered and negative values of standard Gibbs free energy (ΔG°) suggested that the biosorption process is spontaneous.Novelty statementBiomasses of Terminalia chebula shell (TCS), Peltophorum pterocarpum leaf (PPL) and Psidium guajava bark (PGB) reported as first time explored biosorbent for amaranth dye (AD) removal from aqueous solution.Optimal biosorption parameter for AD removal determined.Experimental data examined using isotherm, kinetic and thermodynamic analysis.

Green synthesis of silver nanoparticles transformed synthetic textile dye into less toxic intermediate molecules through LC-MS analysis and treated the actual wastewater

The illegal disposal of waste from textile industries having recalcitrant pollutants is a worldwide problem with more severity in developing nations. We used an ecofriendly method to synthesize silver nanoparticles (AgNPs) from a locally-isolated bacterial strain Bacillus marisflavi TEZ7 and employed them as photocatalysts to degrade not only synthetic azo dyes but also actual textile effluents followed by phytotoxicity evaluation and identification of degradation molecules. The strain TEZ7 was taxonomically identified through the 16S rRNA gene sequence analysis. Biogenic AgNPs were characterized for stabilizing molecules, crystal structure, size, shape and elemental composition by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The photocatalytic degradation efficiency of biogenic AgNPs for three azo dyes such as Direct Blue-1, Methyl Red, and Reactive Black-5 ranged between 54.14 and 96.92% after 5 h of sunlight exposure at a concentration of 100 mg/L. Moreover, the actual wastewater treatment analysis revealed that the 100 mg/L dose of AgNPs significantly decreased the concentration of various physico-chemical parameters of textile effluents such as pH, EC, chlorides, sulphates, hardness, BOD, COD, TSS and TDS. Furthermore, six intermediate molecules of methyl red degradation were identified by LC-MS and it was established by a pot study that these degradation molecules have no phytotoxic effects on rice plants. It was concluded that the AgNPs can be used as an efficient and low-cost strategy for the degradation of azo dyes containing textile wastewaters.

Biosynthesis and characterization of copper oxide nanoparticles and its anticancer activity on human colon cancer cell lines (HCT-116)

The eco-friendly synthesis of nanoparticles through green route from plant extracts have renowned a wide range of application in the field of modern science, due to increased drug efficacy and less toxicity in the nanosized mediated drug delivery model. In the present study, our research groups have biosynthesized the stable and cost effective copper oxide nanoparticles (CuO NPs) from the leaves of (Ormocarpum cochinchinense) O. cochinchinense. The synthesis of crystalline CuO NPs from the leaf extract of O. cochinchinense were confirmed by various analytical techniques like UV-Visible Spectroscopy (UV-Vis), Fourier-Transform Infrared Spectroscopy (FT-IR), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Selected Area Electron Diffraction (SAED) pattern. Further the synthesized CuO NPs were screened for anticancer activity on human colon cancer cell lines (HCT-116) by MTT (3-(4,5-dimethyl-2-tiazolyl)-2,5-diphenyl-2-tetrazolium bromide) assay. The obtained result inferred that the synthesized CuO NPs demonstrated high anticancer cytotoxicity on human colon cancer cell lines (HCT-116) with IC₅₀ value of 40μgmL^-1 were discussed briefly in this manuscript.

Bio-synthesis of peppermint leaf extract polyphenols capped nano-platinum and their in-vitro cytotoxicity towards colon cancer cell lines (HCT 116)

Bio-synthesis of Platinum nanoparticles (Pt NPs) was achieved using Mentha piperita (Peppermint) aqueous leaf extract. Further the ecofriendly synthesized Pt NPs were subjected for various characterization techniques. The characterization results inferred that the green synthesized Pt NPs were said to be in average particle size of 54.3nm. The particles are in spherical shape and it has been entrapped with secondary metabolites (Polyphenols). The polyphenols capped Pt NPs were screened for cytotoxicity against human colon cancer cell line (HCT 116). The results inferred that the ecofriendly synthesized Pt NPs decrease the viability of cancer cells at lower concentrations with IC₅₀ value of 20μg/mL.