AgNPs functionalized with dithizone for the detection of Hg2+ based on surface–enhanced Raman scattering spectroscopy

Mercuric ion (Hg2+), a poisonous metal ion that remained in water ecosystems, can severely damage the human central and peripheral nervous system and kidneys. Consequently, rapid and highly sensitive methods to determine trace Hg2+ are meaningful to discuss. We have proposed a novel approach of surface-enhanced Raman scattering (SERS) for the quantitative analysis of Hg2+ in water samples using dithizone (DTZ) as a Raman reporter. DTZ-modified silver nanoparticles (AgNPs) produced a strong SERS signal. In the presence of Hg2+, the DTZ can capture Hg2+ composing a stable structure, resulting in DTZ leaving the surface of the AgNPs, with an accompanying decrease in the signal. The proposed SERS assay showed a linear range of 10−4–10−8 M, with a limit of detection of 9.83 × 10−9 M. The sensor has low detection cost, rapid detection speed, and uncomplicated sample pretreatment. Furthermore, this method can be successfully utilized to detect Hg2+rapidly in water samples, which sheds new light on the detection of Hg2+ in the environment.

Nanostructured Molybdenum-Oxide Anodes for Lithium-Ion Batteries: An Outstanding Increase in Capacity

This work aimed at synthesizing MoO3 and MoO2 by a facile and cost-effective method using extract of orange peel as a biological chelating and reducing agent for ammonium molybdate. Calcination of the precursor in air at 450 °C yielded the stochiometric MoO3 phase, while calcination in vacuum produced the reduced form MoO2 as evidenced by X-ray powder diffraction, Raman scattering spectroscopy, and X-ray photoelectron spectroscopy results. Scanning and transmission electron microscopy images showed different morphologies and sizes of MoOx particles. MoO3 formed platelet particles that were larger than those observed for MoO2. MoO3 showed stable thermal behavior until approximately 800 °C, whereas MoO2 showed weight gain at approximately 400 °C due to the fact of re-oxidation and oxygen uptake and, hence, conversion to stoichiometric MoO3. Electrochemically, traditional performance was observed for MoO3, which exhibited a high initial capacity with steady and continuous capacity fading upon cycling. On the contrary, MoO2 showed completely different electrochemical behavior with less initial capacity but an outstanding increase in capacity upon cycling, which reached 1600 mAh g−1 after 800 cycles. This outstanding electrochemical performance of MoO2 may be attributed to its higher surface area and better electrical conductivity as observed in surface area and impedance investigations.

Synthesis and Characteristics of Multifunctional Magneto-luminescent Nanoparticles by an Ultrasonic Wave-assisted Stӧber Method

Multifunctional magneto-luminescent nanoparticles (NPs) were synthesised by an ultrasonic wave-assisted Stöber method. The multifunctional NPs are composed of magnetic NPs (Fe3O4) and photoluminescent quantum dots (QDs) (ZnS:Mn) in amorphous silica (SiO2) matrix, which was confirmed by X-ray diffraction, Raman scattering spectroscopy, and transmission electron microscopy (TEM). The multifunctional NPs have high saturation magnetisation at room temperature simultaneously with strong photoluminescence (PL) in visible light, which is promising for biomedical applications.

Experimental implementation of Raman scattering spectroscopy, photoluminescence and some optical properties of silver nanoparticles created by eco-friendly technique

The object of research is studying Raman scattering technique, photoluminescence and some optical properties of silver nanoparticles created by eco-friendly technique which independent on a long time, effort, energy and high temperatures, and with the highest adsorption capacity in order to achieve a high inhibition to paralyze the activity of the bacterial wall, by achieving the highest surface plasmon resonance (SRR). Silver nanoparticles were prepared using Matricaria Flower extract. Characterization of silver nanoparticles and detection of their effectiveness against microbial using two types of bacteria (Escherichia Coli and Staphylococcus aureus ), these nanoparticles were measured using a number of measurements, X-ray diffraction measurement, Energy Dispersion (EDX), (FESEM), U–V Spectroscopy, Fourier Transform Infrared (FTIR), Photoluminescence (PL) properties of silver nanoparticle at room temperature and Raman scattering spectroscopy were investigated. The Scherrer’s equation was used to calculate the crystallite size of Silver nanoparticles, the average crystallite size is 48.64 nm. The PL spectra of silver nanoparticles exhibit two emission bands: one is in the UV region 350 nm and the other is in the visible region 650 nm. This is roughly identical to the absorption spectrum results. The antimicrobial activity was tested against gram negative bacteria (Escherichia coli) and gram positive bacteria (Staphylococcus aureus). Prepared Ag NPs exhibited inhibitory activity in both types of bacteria strains at best selectivity against gram-negative bacteria. An eco-friendly technique is used for synthesizing technique to produce silver nanoparticles with the expected best application properties. These research results suitable to be use the Silver nanoparticles in sensors and many electronic, electrical, medical and biological applications