In recent years, the green synthesis of silver nanoparticles using various plant extracts has attracted great attention. This is because, these methods are simple, inexpensive and, eco-friendly. In this study, it was observed that silver ions were reduced by phlomis leaf extract after 5 min, leading to the formation of crystalline silver nanoparticles. Phlomis species is known as a rich source of flavonoids, phenylpropanoids and other phenolic compounds. The silver nanoparticles produced by the phlomis extract were characterized by different techniques including UV-vis spectrophotometry, X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and FT-IR. The SEM and TEM results indicated that AgNPs were predominantly spherical in shape with an average particle size of 25 nm. In addition, the antibacterial activity of biologically synthesized nanopartilcles against Gram-positive (Staphyloccocus aureus and Bacillus cereus) and Gram-negative (Salmonella typhimurium and Escherichia coli) bacteria was proved. This study, therefore, showed that the phlomis leaf extract could be used for the green synthesis of silver nanoparticles with the appropriate antibacterial activity.

No abstract

Electrospinning is a well‐known technique for producing nanofibers using synthetic and natural polymers like mucilage. In this study, Plantago major Mucilage (PMM) was blended with polyvinyl alcohol (PVA) as a nontoxic adding agent, in order to produce electrospun nanofiber. Electrospinning parameters (voltage, tip‐to‐collector distance, feed rate, and PMM/PVA ratio) were optimized and solution properties were analyzed. The morphology of nanofibers was investigated using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), and Brunauer–Emmett–Teller (BET). Mechanical strength of nanofibers was determined, and cell viability on nanofibers was discussed by MTT assay. The results of SEM indicated that the PMM/PVA (50/50) nanofibers obtained with average diameter of 250 nm. Viscosity, electrical conductivity, and surface tension of PMM/PVA solution were 550 Cp, 575 μS/cm, and 47.044 mN/m, respectively. FTIR and XRD results verified the exiting PMM in produced nanofibers and no chemical reaction between PMM and PVA. Improvement in mechanical strength and cell viability of nanofibers by adding PMM to PVA nanofibers indicated the potential application of PMM‐based nanofibers for medical and food industries. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47852.

A new sensor containing MgFe2O4 nanoparticles in modified multiwall carbon nanotubes (MgFe2O4-MWCNTs) was prepared, and its electrochemical behavior was investigated. MgFe2O4-MWCNTs were used as a voltammetric sensor for the electrocatalytic determination of ciprofloxacin. The synthesized materials were characterized by different methods such as transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry, and electrochemical impedance spectroscopy. The MgFe2O4-MWCNTs electrode showed an oxidation peak potential at around 250 mV. The immobilized composite films facilitate interfacial electron transfer and electrocatalytic activity on the oxidation of ciprofloxacin. The oxidation peak current was dependent on the ciprofloxacin concentration, which was linear over the range of 0.10 -1000 μmol L -1 with a detection limit and quantification limit of 0.01 and 0.08 μmol L -1 , respectively. The relative standard deviation for the determination of 1.0 μmol L -1 ciprofloxacin was 1.1%. The repeatability of the sensor was investigated by preparing nine similar electrodes. The proposed sensor is a selective and fast tool for the determination of ciprofloxacin in tablet, plasma, and urine samples.

Along with the extensive range of exotic nanoparticle (NPs) applications, investigation of magnetic NPs (MNPs) in vitro has ushered modern antibacterial studies into an increasingly attractive research area. A great number of microorganisms exist in the size scales from nanometre to micrometre regions. The enormous potential of engineered MNPs in therapeutic procedures against various drug-resistant bacteria has declined the menace of fatal bacterial infections. Many biocompatible MNPs have been introduced that possess remarkable impacts on various bacterial strains. Conventional synthesis methods such as co-precipitation or hydrothermal techniques have been widely adopted in the production of MNPs. The MNPs for antibacterial applications are mainly required to be superparamagnetic, recyclable and biocompatible. To implement novel strategies in developing new generation antimicrobial magnetic nanomaterials, it is essential to obtain a comprehensive preview of recent achievements in synthesis, proposed antibacterial mechanisms and characterisation techniques of these nanomaterials. This review highlights notable aspects of antibacterial activity in engineered MNPs and nanocomposites including their particle properties (size, shape and saturation magnetisation), antibacterial mechanisms, synthesis methods, testing methods, surface modifications and minimum inhibitory concentrations.