Non-enzymatic electrochemical impedance sensor for selective detection of electro-inactive organophosphate pesticides using Zr-MOF/ZrO/MWCNT ternary composite.

The existence of multiple pesticide residues in fruits and vegetables constitutes a direct peril to living organisms. Therefore, it is crucial to develop a low-cost screening method for determining organophosphate pesticides (OPPs) in food samples. This study describes the solvothermal synthesis of a ternary composite comprising multi-walled carbon nanotubes (MWCNT), zirconium oxide, and a zirconium-metal-organic framework (Zr-MOF).

Highly Selective Room Temperature Detection of NH and NO Using Oxygen-Deficient WO-Supported WS Heterojunctions.

In this paper, we reported the controlled synthesis of tungsten disulfide/reduced tungsten oxide (WS/WO) heterojunctions for highly efficient room temperature NO and ammonia (NH) sensors. X-ray diffraction analysis revealed the formation of the oxygen-deficient WO phase along with WS. Field-emission scanning electron microscopy and transmission electron microscopy displayed the formation of WS flakes over WO nanorods.

Green Chemistry Based Gold Nanoparticles Synthesis Using the Marine Bacterium PBCW2 and Their Multitudinous Activities.

Green chemistry has paved an 'avant-garde avenue' in the production and fabrication of eco-friendly stable nanoparticles employing the utilization of biological agents. In the present study we present the first report on the potential of the marine bacterium PBCW2 for the extracellular production of gold nanoparticles (AuNPs). Utilizing a variety of methods, AuNPs in the cell-free supernatant of (CFS-LBOE) were identified and their antioxidant, antibacterial, and dye-degrading properties were examined.

Visible light-assisted degradation of 4-nitrophenol and methylene blue using low energy carbon ion-implanted ZnO nanorod arrays: Effect on mechanistic insights and stability.

The present investigation demonstrates an enhancement of the visible photocatalytic activities by C ion implantation in ZnO nanorod arrays (NRAs). Vertically aligned ZnO NRAs were prepared by seed layer assisted solution-phase growth and implanted with 70 keV carbon ions at various fluencies: 1E15, 5E15, 1E16, and 3E16 ions/cm. X-ray diffraction and FESEM results revealed the crystalline 1D ZnO NRAs having a length of ∼3 μm with a diameter in the range of 150-200 nm.

Development of the PANI/MWCNT Nanocomposite-Based Fluorescent Sensor for Selective Detection of Aqueous Ammonia.

The present work reported the polyaniline (PANI) and multiwalled carbon nanotube (MWCNT)-based nanocomposite as a sensing material for the determination of aqueous ammonia by the enhanced fluorescence method. The excitation wavelength-dependent photoluminescence (PL) intensity has shown dual emission peaks at 340 and 380 nm that correspond to two different excitation energy states. The pH-based PL intensity and zeta potential variation were analyzed to optimize the suitable medium for aqueous ammonia sensing.

Nitrogen-Implanted ZnO Nanorod Arrays for Visible Light Photocatalytic Degradation of a Pharmaceutical Drug Acetaminophen.

The present study focuses on the effects of nitrogen (N) ion implantation in vertically aligned ZnO nanorod arrays (NRAs) and the photocatalytic degradation of acetaminophen. The X-ray diffraction of these NRAs exhibit a wurtzite structure with a predominant (002) diffraction peak that shifts slightly after N-ion implantation. The field emission scanning electron microscopic images of as-prepared NRAs show a length of ∼4 μm and diameter of ∼150 nm.

Impact of Oxygen Functional Groups on Reduced Graphene Oxide-Based Sensors for Ammonia and Toluene Detection at Room Temperature.

The chemically reduced graphene oxide (rGO) was prepared by the reduction of graphene oxide by hydrazine hydrate. By varying the reduction time (10 min, 1 h, and 15 h), oxygen functional groups on rGO were tremendously controlled and they were named RG1, RG2, and RG3, respectively. Here, we investigate the impact of oxygen functional groups on the detection of ammonia and toluene at room temperature.

Engineering Silicon to Porous Silicon and Silicon Nanowires by Metal-Assisted Chemical Etching: Role of Ag Size and Electron-Scavenging Rate on Morphology Control and Mechanism.

We demonstrate controlled fabrication of porous Si (PS) and vertically aligned silicon nanowires array starting from bulk silicon wafer by simple chemical etching method, and the underlying mechanism of nanostructure formation is presented. Silicon-oxidation rate and the electron-scavenging rate from metal catalysis play a vital role in determining the morphology of Si nanostructures. The size of Ag catalyst is found to influence the Si oxidation rate.

Robust water repellent ZnO nanorod array by Swift Heavy Ion Irradiation: Effect of Electronic Excitation Induced Local Chemical State Modification.

Tailoring the surface properties by varying the chemistry and roughness could be of interest for self-cleaning applications. We demonstrate the transformation of hydrophobic ZnO Nano rod (NR) array into superhydrophobic nature by changing the local chemical state and without altering the surface roughness by swift heavy ion (SHI) irradiation. The aligned ZnO NR arrays were irradiated using 150 MeV Ag ions with different fluences from 5E10 to 3E12 ions/cm.

One step 'dip' and 'use' Ag nanostructured thin films for ultrahigh sensitive SERS Detection.

A simple one step galvanic displacement method which involves dipping of the silicon substrate in the AgNO3/HF solution and using it for SERS application without any further process is demonstrated. The size and shape of the Ag nanoparticles changes as the deposition time is increased. Initially the shape of the particles was nearly spherical and as it grows, becomes oblong and then coalesce to form a discontinuous film with vertically grown hierarchical Ag nanostructures.

Multiwalled Carbon Nanotube Oxygen Sensor: Enhanced Oxygen Sensitivity at Room Temperature and Mechanism of Sensing.

A pyrolysis assisted method was applied for the synthesis of defect controlled carbon nanotubes (CNTs) by varying different growth temperatures. The fabricated resistive devices containing a random network of CNTs were tested for oxygen sensing under standard room-temperature and pressure conditions. Nanotubes grown at moderate growth temperatures (870 °C), when exposed to different concentrations of oxygen, displayed a higher sensitivity (3.

In vitro bacterial cytotoxicity of CNTs: reactive oxygen species mediate cell damage edges over direct physical puncturing.

Understanding the bacterial cytotoxicity of CNTs is important for a wide variety of applications in the biomedical, environmental, and health sectors. A majority of the earlier reports attributed the bactericidal cytotoxicity of CNTs to bacterial cell membrane damage by direct physical puncturing. Our results reveal that bacterial cell death via bacterial cell membrane damage is induced by reactive oxygen species (ROS) produced from CNTs and is not due to direct physical puncturing by CNTs.