Green Synthesis of ZnO and V-Doped ZnO Nanoparticles Using Vinca rosea Plant Leaf for Biomedical Applications.

The present work focused on the synthesis of Vinca rosea leaf extract derived ZnO and vanadium-doped ZnO nanoparticles (V-ZnO NPs). The chemical composition, structural, and morphology of ZnO and vanadium-doped ZnO NPs were examined by FTIR, XRD, and SEM-EDX. The FTIR confirmed the presence of functional groups corresponding to ZnO and vanadium-doped ZnO NPs. SEM-EDX clearly indicated the morphology of synthesised NPs; the hexagonal crystal of NPs was confirmed from XRD. In addition, the cytotoxic effect of ZnO and V-ZnO NPs was estimated against the breast cancer (MCF-7) cell line. From the assay, Vinca rosea (V. rosea) capped ZnO NPs have shown improved cytotoxic activity than that of Vinca rosea capped V-ZnO NPs. ZnO and vanadium-doped ZnO NPs showed the strongest antibacterial activity against Enterococcus, Escherichia coli, Candida albicans, and Aspergillus niger. The α-amylase inhibition assays demonstrated antidiabetic activity of synthesised NPs. From the assay test, results obtained Vinca rosea capped ZnO nanoparticles prepared using the green approach showed high effective antioxidant, antidiabetic activity, and anticancer activity than vanadium-doped ZnO NPs.

Receptor-free phenothiazine derivative as fluorescent probe for picric acid: Investigation of the inner filter effect channel.

In this study, a highly fluorescent and receptor-free phenothiazine derivative (PDAB) was developed to detect picric acid. A combination of steady-state and time-resolved fluorescence studies was conducted to examine the excited state behavior of PDAB with picric acid in solution. The PDAB probe displayed a significant degree of selectivity and was highly sensitive to picric acid, with an extremely low detection limit of 9.82 nM. Time-resolved fluorescence quenching studies exhibit direct evidence of an inner filter effect-based sensing mechanism. Using the Parker equation, a thorough analysis was done to correct the inner filter effect on the sensing of picric acid. Overall, these studies provide critical information on the sensing mechanism for picric acid detection.

Green route synthesis of ZnO nanoparticles using Senna auriculata aqueous flower extract as reducing agent and evaluation of its antimicrobial, antidiabetic and cytotoxic activity.

The nanoparticles have unique and superior properties which make them applicable in almost every field of human life. Among the various methods that exist for the synthesis of nanoparticles, green synthesis is one of the best economic and eco-friendly methods compared with other conventional chemical methods. The nanoparticles synthesized by this method are also free from toxicity properties. This paper describes one such green synthesis method for zinc oxide nanoparticles (ZnO NPs) using the aqueous flower extract of Senna auriculata. The synthesized nanoparticles (SA-ZnO NPs) have been examined using UV-Vis spectrophotometer, photoluminescence spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The antibacterial and antifungal activities of the synthesized NPs were evaluated against gram-positive bacteria (S. aureus, B. subtilis), gram-negative bacteria (E. coli, S. typhi) and fungal organisms (C. albicans, A. nigar) using disc diffusion method. Furthermore, the antidiabetic and anticancer activities of the NPs were also been examined by α-amylase inhibition assay and MTT assay, respectively. These studies ensured that the SA-ZnO NPs have significant antimicrobial, antidiabetic and anticancer activities.

Anti-Dengue Activity of ZnO Nanoparticles of Crude Fucoidan from Brown Seaweed S.marginatum.

Dengue fever is a rapidly spreading infection that affects people all over the tropics and subtropics, posing a significant public health threat. The brown seaweed Stoechospermum marginatum was found all over the world, from South Africa (Indian Ocean) to Australia (Pacific Ocean), among other places. In India, it is only available along the coast of the Bay of Bengal, which is a small region. Various metal oxides were proved to be successful in the formation of nanoparticles and zinc is one among them. In this present study, an attempt was made to study the anti-dengue activity of green synthesized zinc oxide nanoparticles of crude fucoidan isolated from brown seaweed S. marginatum. The fucoidan was isolated from the seaweed by acid extraction method and then characterized by UV, HPLC, and Fourier Transform Infra-Red (FT-IR) Spectroscopy. Then it was biosynthesized into ZnO nanoparticles and characterized by SEM-EDAX analysis. The results showed the formation of fucoidans and SEM studies showed the crystalline nature of the synthesized nanoparticles. The size of nanoparticles was in the range of 80-126 nm. The synthesized nanoparticles were tested with the C6/36 cell line and it was shown 99.09% of anti-dengue activity against the tested cell line. As an antiviral agent, the ZnO nanoparticles of fucoidans have been shown to be an excellent lead molecule for the treatment of dengue fever.

Antiproliferative Activity of Green Synthesised Silver Nanoparticles of Cassia Marginata Roxb.

Green synthesised silver nanoparticles (AgNPs) have been identified as a promising new therapy pathway for cancer because of their anti-angiogenic potency. In the present study, CM-AgNPs were biosynthesized using aqueous leaf extract of Cassia marginata Roxb (CM) and were confirmed by spectral studies like UV-Visible and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic techniques. The structure and shape of the biosynthesized CM-AgNPs were confirmed by scanning electron microscope (SEM), energy-dispersive spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) studies. The antioxidant activity of the synthesized nanoparticles were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay methods, and the IC50 values were found to be 19.58 ± 1.62 and 742.33 ± 14.57 µg, respectively. The anticancer activity of CM-AgNPs was evaluated against human breast cancer cell lines MCF-7 and MDA-MB-231 by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and the IC50 values were found to be 21.02 ± 1.67 and 26.21 ± 0.33 µg/ml, respectively. These results provide promising information about the biosynthesized CM-AgNPs that can be used in the development of novel anticancer drugs.