Fabrication of Nickel Tetrasulfonated Phthalocyanine Functionalized Multiwalled Carbon Nanotubes on Activated Glassy Carbon Electrode for the Detection of Dopamine

The nickel tetrasulfonated phthalocyanine (NiTsPc) functionalized multiwalled carbon nanotube (MWCNT) nanocomposite was prepared by a simple sonochemical method. Here, NiTsPc served as a dispersing agent for MWCNT via π? π interaction between MWCNT and NiTsPc. The activated glassy carbon electrode (AGCE) modified with MWCNT‐NiTsPc composite exhibited a good electrocatalytic ability toward dopamine and displayed a good linear dependence in the concentration range of 20 nM–1.384 mM with a sensitivity of 0.17 µA µM^?1 cm^?2. The detection limit is 1 nM based on the signal‐to‐noise ratio of 3.     

Metal Complexes of Donor-functionalized Fluorinated β-Ketoiminates – Synthesis,Structure, and CVD Application

Six alkali metal complexes of partly-fluorinated, donor-functionalized β-ketoiminate ligands [L¹Li ( 1 ), L¹Na ( 2 ), L¹K ( 3 ), L¹Cs ( 4 ), L¹ = OC(CF₃)CHC(CH₃)NCH₂CH₂OCH₃; L²Li ( 5 ), L²Na ( 6 ), L² = OC(CF₃)CHC(CH₃)NCH₂CH₂N(CH₃)₂] were prepared and structurally characterized. Reactions of L¹Li with PtCl₂ gave the homoleptic Pt complex L¹₂Pt ( 7 ), which was characterized spectroscopically and by single-crystal X-ray diffraction and whose promising application as CVD precursor (chemical vapor deposition) is shown. Polycrystalline, pure Pt films were grown at 500 °C on SiO₂@Si(100) substrates at 10^–3 mbar and characterized by XRD, SEM, AFM, EDX and XPS.     

New hexaphosphane ligands 1,3,5-C6H3{p-C6H4N(PX2)2}3 [X = Cl, F, C6H3OMe(C3H5)]: synthesis, derivatization and palladium(II) and platinum(II) complexes

A novel dodecachlorohexaphosphane, 1,3,5-C(6)H(3)[p-C(6)H(4)N(PCl(2))(2)](3) (1) was synthesized by reacting 1,3,5-tris(4'-anilino)benzene with phosphorus trichloride. Fluorination of 1 with SbF(3) produces 1,3,5-C(6)H(3)[p-C(6)H(4)N(PF(2))(2)](3) (2). The derivatization of chlorohexaphosphane with an aryloxy substituent and its palladium(II) and platinum(II) complexes are also described.     

Electrochemical evidence for catalytic water oxidation mediated by a high-valent cobalt complex

The pH-dependent electrochemical behavior for a Co(II) complex, [Co(Py5)(OH(2))](ClO(4))(2) (1; Py5 = 2,6-(bis(bis-2-pyridyl)methoxymethane)pyridine), indicates consecutive (proton-coupled) oxidation steps furnish a Co(IV) species that catalyzes the oxidation of water in basic media.     

Crystal growth of PZN‐PT single crystals and critical issues for higher piezoelectric coefficient

Single crystals of lead zinc niobate‐lead titanate (1‐x)Pb(Zn_1/3Nb_2/3)O₃–xPbTiO₃ for x = 8% and 9% have been grown by flux method using Lead Oxide (PbO) as flux. Low scan rate XRD has been carried out to investigate on the structural influence of the compositional variations in the grown crystals. Transmission spectra in the range of UV‐Vis‐Near IR and mid IR regions have been carried out to understand the distortions caused in the BO₆ octahedral lattice. Morphological aspects of as‐grown PZN‐PT crystals have also been investigated. Dielectric measurements clearly explained the dependence of T_c and diffusiveness with PT content. The values of P_r and E_cobtained from P‐E loops suggest the presence of ordered domain state in these PZN‐PT single crystals. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Di- and tetranulcear Ru complexes of phenylene-1,4-diaminotetra(phosphonite), p-C6H4[N{P(OC6H4OMe-o)2}2]2 and their catalytic investigation towards transfer hydrogenation reactions

The stoichiometric reaction of phenylene-1,4-diaminotetra(phosphonite), p-C₆H₄[N{P(OC₆H₄OMe-o)₂}₂]₂ (P₂NФNP₂) (1) with [RuCl₂(p-cymene)]₂ in acetonitrile produces cis,cis-[{RuCl₂(CH₃CN)₂}₂(P₂NФNP₂)] (2), whereas the similar reaction of 1 with [RuCl₂(p-cymene)]₂ in THF medium affords a tri-chloro-bridged tetrametallic complex, [{(η⁶-p-cymene)Ru₂(μ₂-Cl)₃Cl}₂(P₂NФNP₂)] (3) irrespective of the stoichiometry and reaction conditions. The formation and structure of complexes 2 and 3 are assigned through various spectroscopic and micro analysis data. The molecular structure of 2 is confirmed by single crystal X-ray diffraction study. The catalytic activities of complexes 2 and 3 have been investigated in transfer hydrogenation reactions.     

Electrochemical Synthesis of β‐Cyclodextrin Functionalized Silver Nanoparticles and Reduced Graphene Oxide Composite for the Determination of Hydrazine

β‐cyclodextrin (β‐CD) functionalized silver nanoparticles (AgNPs) and reduced graphene oxide (RGO) via one step electrochemical potentiodyanamic method has been prepared. Scanning electron microscopy, Energy‐Dispersive X‐ray spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to study the role of β‐CD on preparation of AgNPs and RGO. RGO/β‐CD/AgNPs modified GCE showed good electrochemical activity towards electro‐oxidation of hydrazine in terms of decreasing the over potential and increasing the peak current. The kinetic parameters such as electron transfer coefficient (α) and diffusion coefficient (Do) of the modified electrode towards hydrazine were determined to be 0.66 and 0.97×10^?6 cm² s^?1, respectively. The LOD of our sensor was many folds lower than that of recommended concentration of hydrazine in drinking water by United States Environmental Protection Agency and World Health Organization. The sensor exhibited a wide linear range from 0.08 to 1110 µM and a very low detection limit (LOD) of 1.4 nM. In addition, the sensor selectively determined hydrazine even in the presence of common interferents.     

Design and evaluation of bioadhesive in-situ nasal gel of ketorolac tromethamine

The present study was aimed at developing safe and effective bioadhesive gelling systems of ketorolac tromethamine, a potent non-narcotic analgesic with moderate anti-inflammatory activity for nasal systemic delivery. Chitosan and pectin based gelling systems were prepared with variables like polymer concentration and type. These systems were characterized in terms of their physical properties, in vitro bioadhesion, in vitro drug release and long-term stability. The anti-inflammatory activity and mucosal irritancy of selected gels were also evaluated in rats and these results were compared with per oral, intraperitoneal and nasal solution administration of ketorolac tromethamine. All the prepared formulations gelled immediately at the nasal mucosal pH and showed longer contact time. Addition of hydroxypropyl methylcellulose (HPMC) in both chitosan and pectin based gelling systems increased the viscosity and gel strength. All the formulated gels exhibited pseudoplastic rheology and diffusion-controlled drug release. The results from stability studies revealed that the prepared thermogels showed marginal decrease in viscosity but at the same time, no significant difference in drug content, and in vitro release characteristics were observed before and after accelerated studies. The developed gelling systems produced only mild to negligible irritant effect to nasal mucosae as compared to control group.     

Enhanced photodegradation of 2,4-dinitrophenol by n–p type TiO2/BiOI nanocomposite

Photocatalysis has recently been regarded as one of the most viable technologies for water treatment. Scholars all over the world are focusing on nanocomposites for water treatment for efficient and effective sanitization of bodies of water. Because of their high surface area, high chemical reactivity, excellent mechanical strength, low cost, and nanoscale composite materials have enormous potential to purify water in a various way. In this study, n-type TiO₂ was synthesized and tailored to produce a TiO₂/BiOI n–p nanocatalyst for enhanced photodegradation of 2,4-dinitrophenol (2,4-DNP) under UV-A and solar light respectively. Because of the formation of a heterojunction between BiOI and TiO₂, the photocatalytic activity in TiO₂/BiOI absorbs strongly in both the UV and visible regions and it has a lower recombination rate of the e^-/h⁺ pairs. Furthermore, the generation of OH^?, O₂^?– radicals during the oxidation process is attributed to the photodegradation of 2,4-DNP. The results revealed that the TiO₂/BiOI manifest outperformed BiOI and TiO₂ in terms of photocatalytic function. XRD, BET, HR-SEM-EDX with ECM, HR-TEM, FT-IR, PL, and UV-DRS techniques determined the photocatalyst composition. The HR-SEM images clearly showed that the particles are less than 27 ?nm in size. Thus, nanocomposite materials have played an important role in water purification.     

Direct Electrochemistry of Glucose Oxidase at Reduced Graphene Oxide and β‐Cyclodextrin Composite Modified Electrode and Application for Glucose Biosensing

A simple glucose biosensor has been developed based on direct electrochemistry of glucose oxidase (GOx) immobilized on the reduced graphene oxide (RGO) and β‐cyclodextrin (CD) composite. A well‐defined redox couple of GOx appears with a formal potential of ～?0.459 V at RGO/CD composite. A heterogeneous electron transfer rate constant (K_s) has been calculated for GOx at RGO/CD as 3.8 s^?1. The fabricated biosensor displays a wide response to glucose in the linear concentrations range from 50 µM to 3.0 mM. The sensitivity and limit of detection of the biosensor is estimated as 59.74 µA mM^?1 cm^?2 and 12 µM, respectively.