Jayabrata Das

Sesbania grandiflora leaf extract mediated green synthesis of antibacterial silver nanoparticles against selected human pathogens.

Simple, effective and rapid approach for the green synthesis of silver nanoparticles (AgNPs) using leaf extract of Sesbania grandiflora and their in vitro antibacterial activity against selected human pathogens has been demonstrated in the study. Various instrumental techniques were adopted to characterize the synthesized AgNPs viz. UV-Vis, FTIR, XRD, TEM, EDX and AFM. Surface Plasmon spectra for AgNPs are centered at 422 nm with dark brown color. The synthesized AgNPs were found to be spherical in shape with size in the range of 10-25 nm. The presence of water soluble proteins in the leaf extract was identified by FTIR which were found to be responsible for the reduction of silver ions (Ag(+)) to AgNPs. Moreover, the synthesized AgNPs showed potent antibacterial activity against multi-drug resistant (MDR) bacteria such as Salmonella enterica and Staphylococcus aureus.

Bio-Inspired Green Nanoparticles: Synthesis, Mechanism, and Antibacterial Application

In the recent years, noble nanoparticles have attracted and emerged in the field of biology, medicine and electronics due to their incredible applications. There were several methods have been used for synthesis of nanoparticles such as toxic chemicals and high energy physical procedures. To overcome these, biological method has been used for the synthesis of various metal nanoparticles. Among the nanoparticles, silver nanoparticles (AgNPs) have received much attention in various fields, such as antimicrobial activity, therapeutics, bio-molecular detection, silver nanocoated medical devices and optical receptor. Moreover, the biological approach, in particular the usage of natural organisms has offered a reliable, simple, nontoxic and environmental friendly method. Hence, the current article is focused on the biological synthesis of silver nanoparticles and their application in the biomedical field.

Direct electrochemical reduction of hematite decorated graphene oxide (α-Fe 2 O 3 @erGO) nanocomposite for selective detection of Parkinson's disease biomarker

An unusual approach is reported herein to fabricate magnetic hematite (α-Fe2O3) decorated electrochemically reduced graphene oxide (α-Fe2O3@erGO) nanocomposite. The method utilizes direct electrochemical reduction of self-assembled, ex-situ synthesized α-Fe2O3 anchored GO to erGO (α-Fe2O3@erGO) on glassy carbon electrode (GCE) for selective detection dopamine (DA), an important biomarker of Parkinsons disease. The formation of α-Fe2O3@erGO/GCE has been confirmed by XPS and Raman spectroscopy. α-Fe2O3@erGO modified GCE exhibits synergistic catalytic activity nearly 2.2 and 5 fold higher than α-Fe2O3@GO and other modified electrodes, respectively towards oxidation of DA. The fabricated sensor exhibited linear dynamic ranges over 0.25 - 100 µM in response to DA with a LOD of 0.024 µM (S/N = 3), LOQ of 0.08 µM (S/N = 10), and a sensitivity of 12.56 µA µM-1 cm-2. Finally, the practical analytical application of the proposed α-Fe2O3@erGO/GCE was investigated for the determination of DA in commercially available pharmaceutical formulation and human serum samples, and showed satisfactory recovery results towards DA.