Biogenic Synthesis of Iron Oxide Nanoparticles Using Enterococcus faecalis: Adsorption of Hexavalent Chromium from Aqueous Solution and In Vitro Cytotoxicity Analysis

The biological synthesis of nanoparticles is emerging as a potential method for nanoparticle synthesis due to its non-toxicity and simplicity. In the present study, a bacterium resistant to heavy metals was isolated from a metal-contaminated site and we aimed to report the synthesis of Fe3O4 nanoparticles via co-precipitation using bacterial exopolysaccharides (EPS) derived from Enterococcus faecalis_RMSN6 strains. A three-variable Box–Behnken design was used for determining the optimal conditions of the Fe3O4 NPs synthesis process. The synthesized Fe3O4 NPs were thoroughly characterized through multiple analytical techniques such as XRD, UV-Visible spectroscopy, FTIR spectroscopy and finally SEM analysis to understand the surface morphology. Fe3O4 NPs were then probed for the Cr(VI) ion adsorption studies. The important parameters such as optimization of initial concentration of Cr(VI) ions, effects of contact time, pH of the solution and contact time on quantity of Cr(VI) adsorbed were studied in detail. The maximum adsorption capacity of the nanoparticles was found to be 98.03 mg/g. The nanoparticles could retain up to 73% of their efficiency of chromium removal for up to 5 cycles. Additionally, prepared Fe3O4 NPs in the concentration were subjected to cytotoxicity studies using an MTT assay. The investigations using Fe3O4 NPs displayed a substantial dose-dependent effect on the A594 cells. The research elucidates that the Fe3O4 NPs synthesized from EPS of E. faecalis_RMSN6 can be used for the removal of heavy metal contaminants from wastewater

Fabrication of an Electrocatalyst Based on Rare Earth Manganites Incorporated with Carbon Nanofiber Hybrids: An Efficient Electrochemical Biosensor for the Detection of Anti-Inflammatory Drug Mefenamic Acid

Pharmaceutical and personal care products are emerging as a new category of environmental pollution. Analytical drug detection from a biological sample for detection is still crucial today. Mefenamic acid (MA) is an anti-inflammatory drug utilized for its antipyretic and analgesic properties, which is harmful to patients at higher dosages and is also recognized as a chemical pollutant that harms the environment. In this view, Dysprosium manganite/carbon nanofiber (DMO/CNF) was prepared by hydrothermal method for the electrochemical detection of MA. DMO/CNF/GCE exhibits high selectivity, excellent anti-interference, good stability, and reproducibility toward the detection of MA. The enhanced electrochemical performance of DMO/CNF/GCE was attributed to their synergetic interaction. Under optimized conditions, DMO/CNF/GCE shows a wide linear range of 0.01–741 μM and a low LOD of 0.009 μM. Satisfactory recoveries were obtained for human blood and tablet samples. Thus, the proposed DMO/CNF nanocomposite emerges as a promising material for the detection of MA

Electrochemical Monitoring of Sulfadiazine via La@CeO Incorporated with Reduced Graphene Oxide

In recent years, indiscriminate consumption and dumping of antibiotics have become destructive to human health and causes ecotoxicological pollution. Here, the irregular particle nanosized dendrite structure of lanthanum-doped cerium oxide (LCO) decorated with sheet-like reduced graphene oxide (RGO) composite was utilized to detect the sulfonamide-based drug sulfadiazine (SZ). LCO@RGO nanocomposite was prepared using the hydrothermal method, the synergistic effect between LCO and RGO facilitates electron transferability and conductivity which enhances the electrochemical properties toward the detection of SZ. The detection of SZ expressed a lower detection limit (0.005 µM) and linear range (0.01–265 µM) of the fabricated LCO@RGO/GCE electrode toward SZ, analyzed using the highly sensitive DPV technique. Also, DPV was utilized to determined shows good repeatability, reproducibility, and storage stability of fabricated LCO@RGO/GCE. Moreover, effective practicability was proven in human blood serum and river water samples with great recovery results. All the above probes the synthesized LCO@RGO’s thriving and outstanding electrocatalytic performance of this nanocomposite’s highly sensitive detection of SZ in real biological and environmental samples

Zinc molybdate/functionalized carbon nanofiber composites modified electrodes for high-performance amperometric detection of hazardous drug Sulfadiazine

Pharmaceuticals are generally designed to be nondegradable or slowly degradable to prevent chemical degradation as it is employed as therapeutics for human or animal. This results in a widespread risk when they enter, accumulate or persist in the environment. Pharmaceutical pollution is emerging as wide-reaching concern due to its ostensible consequences, by dissemination in the environment. This demands for inventing novel analytical routes to monitor and mitigate pharmaceutical pollutants. Therefore, this paper presents synthesis of Zinc molybdate nano particles embedded on functionalized carbon nanofibers to fabricate glassy carbon electrode towards sensitive detection of Sulfadiazine (SDZ). The synergistic effect produced in the composite had enabled it with improved charge transfer kinetics and benefited with more active surface area. The proposed ZnMoO4/f-CNF sensor shows significant static characteristics such as wide linear response ranges (0.125 to1575.2 μM), low detection limit (0.0006 μM) and selectivity, and increased stability. Also, its practicability was analyzed by SDZ detection in real samples

A Review on Green Synthesis of Nanoparticles and Their Diverse Biomedical and Environmental Applications

In recent times, metal oxide nanoparticles (NPs) have been regarded as having important commercial utility. However, the potential toxicity of these nanomaterials has also been a crucial research concern. In this regard, an important solution for ensuring lower toxicity levels and thereby facilitating an unhindered application in human consumer products is the green synthesis of these particles. Although a naïve approach, the biological synthesis of metal oxide NPs using microorganisms and plant extracts opens up immense prospects for the production of biocompatible and cost-effective particles with potential applications in the healthcare sector. An important area that calls for attention is cancer therapy and the intervention of nanotechnology to improve existing therapeutic practices. Metal oxide NPs have been identified as therapeutic agents with an extended half-life and therapeutic index and have also been reported to have lesser immunogenic properties. Currently, biosynthesized metal oxide NPs are the subject of considerable research and analysis for the early detection and treatment of tumors, but their performance in clinical experiments is yet to be determined. The present review provides a comprehensive account of recent research on the biosynthesis of metal oxide NPs, including mechanistic insights into biological production machinery, the latest reports on biogenesis, the properties of biosynthesized NPs, and directions for further improvement. In particular, scientific reports on the properties and applications of nanoparticles of the oxides of titanium, cerium, selenium, zinc, iron, and copper have been highlighted. This review discusses the significance of the green synthesis of metal oxide nanoparticles, with respect to therapeutically based pharmaceutical applications as well as energy and environmental applications, using various novel approaches including one-minute sonochemical synthesis that are capable of responding to various stimuli such as radiation, heat, and pH. This study will provide new insight into novel methods that are cost-effective and pollution free, assisted by the biodegradation of biomass