Deposition of Poly(diphenylamine-co-3-aminobenzonitrile)/Palladium Nanocomposite Film and Evaluation of Electrocatalytic Activity Toward Borohydride Oxidation.

New nanocomposites, poly(diphenylamine-co-3-aminobenzonitrile)/palladium (P(DPA-co-3ABN)/Pd) and poly(diphenylamine)/palladium (PDPA/Pd), have been prepared by pulse potentiostatic method and used as electrocatalysts for borohydride oxidation. Linear sweep voltammogram of P(DPA-co-3ABN)/Pd-ME exhibited the oxidation wave between -0.8 V and 0.

Nanodiamond based sponges with entrapped enzyme: a novel electrochemical probe for hydrogen peroxide.

A "modular approach" has been demonstrated for the preparation of nanodiamond (ND) based sponges (NS) with entrapped enzyme (horseradish peroxidase, HRP) (ND-NS(HRP)) and utilization as an electrochemical probe for detection of hydrogen peroxide (H₂O₂). ND-NS comprises ND, porous poly(aniline)-poly(2-acrylamido 2-methyl propane sulfonic acid) (PANI-PAMPSA) network and entrapped HRP. Field emission scanning electron microscope image of ND-NS(HRP) reveals sponge like suprastructure comprising interconnected nanospheres with numerous openings/pinholes/cavities.

Development of a novel cyano group containing electrochemically deposited polymer film for ultrasensitive simultaneous detection of trace level cadmium and lead.

Poly(diphenylamine-co-2-aminobenzonitrile) (P(DPA-co-2ABN)), a cyano group containing conducting polyaniline derivative, has been electrodeposited developed as the new material and utilized for the simultaneous electrochemical determination of trace levels of cadmium (Cd(2+)) and lead (Pb(2+)). P(DPA-co-2ABN) film preconcentrates effectively through cyano chelation and electrochemically strips the heavy metal ions with well separated potentials, which are beneficially utilized for ppb level simultaneous detection of Cd(2+) and Pb(2+). Differential pulse voltammetry studies revealed that Cd(2+) and Pb(2+) ions were simultaneously stripped with well-defined, separated and sharp peaks for Cd(2+) and Pb(2+).

Large-scale preparation of polyaniline nanospheres anchored with thiol-stabilized gold nanoparticles.

Reported herein is the preparation of a new nanostructured composite consisting of PANI(SH) (where PANI(SH) is poly(aniline-co-4-aminothio phenol)) and gold nanoparticles (AuNPs)) via "seed"-induced bulk polymerization. The PANI(SH)-AuNPs composite was designated as PANI(SH)-Au-NS(P). The composite was characterized in terms of its morphology and structural, thermal, and electrochemical properties.

Sensitive electrochemical detection of superoxide anion using gold nanoparticles distributed poly(methyl methacrylate)-polyaniline core-shell electrospun composite electrode.

In the present communication, a novel composite nanofibrous electrode is developed for the detection of superoxide anion (O(2)˙(-)) in phosphate buffered saline (PBS). The composite fiber electrode is fabricated by dispersing gold nanoparticles onto poly(methyl methacrylate) (PMMA)-polyaniline (PANI) core-shell electrospun nanofibers. The constructed architecture is proven to be a favorable environment for the immobilization of the enzyme, superoxide dismutase (SOD).

Strategically functionalized carbon nanotubes as the ultrasensitive electrochemical probe for picomolar detection of sildenafil citrate (Viagra).

The present work demonstrates the utility of the functionalized carbon nanotubes, poly(4-aminobenzene sulfonic acid) (PABS) grafted multiwalled carbon nanotubes, MWNT-g-PABS, as an electrode modifier towards achieving ultrasensitive detection of a model drug, sildenafil citrate (SC). PABS units in MWNT-g-PABS interact with SC, pre-concentrate and accumulate at the surface. The electron transduction from SC to electrode is augmented via MWNT-g-PABS.

Preparation of poly(1,5 diamino naphthalene) nanobelts/nanodiscs through a "hard-soft combined templates" approach.

This is the first report on the preparation of nanobelts/nanodiscs of poly(1,5-diamino naphthalene) (PDAN-P) in bulk quantities through a "hard-soft combined templates" approach. PDAN was nanostructured within the channels of MCM-41 (hard template) in the presence of beta-napthalene sulfonic acid (beta-NSA) (soft template) and further used as the seed for the bulk preparation of pure PDAN nanobelts/nanodiscs of PDAN (PDAN-P). Field emision scanning electron microscope image reveals that a typical nanobelt has a length of approximately 3 microm, with a uniform breadth of approximately 150 nm and a thickness of approximately 50 nm.

Preparation of poly(2-amino thiophenol) nanodiscs by a "combined hard-soft template" approach and characterization.

A seed induced chemical oxidative polymerization was used for the preparation of pure poly(2-amino thiophenol) nanodiscs (P2AT-NDs (P)). Two templates, (hard (MCM-41) and soft (β-napthalene sulfonic acid), were utilized for the preparation of the seed, P2AT nanostructures loaded MCM-41. The field emission scanning electron microscopy reveals nanodisc morphology for P2AT (P).

Electrospun carbon nanotubes-gold nanoparticles embedded nanowebs: prosperous multi-functional nanomaterials.

Electrospinning was employed to prepare new multi-functional nanowebs. Cyclodextrin based inclusion complex (CD-IC) was used to disperse multiwalled carbon nanotubes (MWNT) within electrospun polyvinylidene fluoride nanofibrous membranes (PVdF-NFM). Subsequently, MWNT(CD-IC)/PVdF-NFM was loaded with gold (Au) particles.

Nanomolar detection of dopamine at multi-walled carbon nanotube grafted silica network/gold nanoparticle functionalised nanocomposite electrodes.

This is the first report on ultrahigh sensitive and selective electrochemical detection of nanomolar concentrations of dopamine (DA) in the presence of ascorbic acid (AA) at a modified electrode fabricated with a new functional nanocomposite, comprising of multi-walled carbon nanotube (MWNT) grafted silica network (silica NW) and gold nanoparticles (Au NPs) (MWNT-g-silica NW/Au NPs). The fabrication of MWNT-g-silica NW/Au NPs modified electrodes involves two steps: covalent functionaliztion of MWNT with silica NW and deposition of Au NP. Cyclic voltammetry and differential pulse voltammetry experiments were performed for the individual and simultaneous electrochemical detection of DA (in nanomolar concentrations) and AA.

Covalently linked silica-multiwall carbon nanotube-polyaniline network: an electroactive matrix for ultrasensitive biosensor.

A three dimensional network comprising of covalently linked multi-walled carbon nanotubes (MWNT), silica and polyaniline chains (MWNT-Silica-PANI-NW) was prepared and used as the matrix for immobilization of an enzyme (horseradish peroxidase, HRP). MWNT-Silica-PANI-NW-HRP electrode showed superior performances over the individual components and their binary combinations, in terms of enzyme stability (minimum leaching to the medium), fast electron transfer from the enzyme to the electrode (2.11s(-1)), high sensitivity (58.

An electrochemical glucose biosensor exploiting a polyaniline grafted multiwalled carbon nanotube/perfluorosulfonate ionomer-silica nanocomposite.

A glucose biosensor was fabricated with loading of glucose oxidase (GOx) into a new organic-inorganic hybrid nanocomposite. The preparation involves formation of silica network into a Nafion (perfluorosulfonate ionomer) and subsequent loading of polyaniline grafted multiwalled carbon nanotubes (MWNT-g-PANI) onto Nafion-silica nanocomposite. Field emission scanning electron microscopy (FE-SEM) of Nafion-silica/MWNT-g-PANI composite reveals the presence of spherical silica particles (sizes in the range 250 nm-1 microm) and tubular MWNT-g-PANI particles.

Synthesis and characterization of nanostructured wires (1D) to plates (3D) LiV3O8 combining sol-gel and electrospinning processes.

Using the combined techniques of sol-gel and electrospinning, nanostructures (wire (1D) to plates (3D)) of LiV3O8 are prepared with poly vinyl alcohol (PVA) as the template. A precursor gel of LiOH-V2O5 is prepared in alkaline medium. Fibrous membranes of PVA with different weight% of LiOH-V2O5 gel are prepared by electrospinning and designated as PVA/LiOH-V2O5 composite membrane fibers.

Fabrication and properties of poly(vinylidenefluoride)/PbS/Au heterogeneous nanostructures.

We report on the fabrication of polyvinylidenefluoride (PVdF) PVdF/PbS and PVdF/PbS/Au heterogeneous nanostructures by the processes, electrospinning and chemical treatment. Initially electrospinning a solution consisting of PVdF and lead acetate was used to form PVdF nanofibers loaded with Pb ions. Exposure of Pb ions loaded PVdF fibers to H2S resulted in PVdF/PbS nanostructures.

Fabrication of a novel layer-by-layer film based glucose biosensor with compact arrangement of multi-components and glucose oxidase.

Layer-by-layer (LbL) film based glucose biosensor was fabricated with alternative layers of a nanocomposite (comprising of multiwalled carbon nanotubes (MWNTs), Au nanoparticles (Au NPs) and thiol functionalized polyaniline (PANI(SH)) and glucose oxidase (GOx). The successful formation of multilayers was confirmed by UV-visible spectroscopy. The components in the nanocomposite provide adequate electron transfer path between GOx and the electrode.

Development of a stable cholesterol biosensor based on multi-walled carbon nanotubes-gold nanoparticles composite covered with a layer of chitosan-room-temperature ionic liquid network.

A novel amperometric biosensor was fabricated based on the immobilization of cholesterol oxidase (ChOx) into a cross-linked matrix of chitosan (Chi)-room-temperature ionic liquid (IL) (1-butyl-3-methylimidazolium tetrafluoroborate). Initially, the surface of bare electrode (indium tin oxide coated glass) was modified with the electrodeposition of Au particles onto thiol (-SH) functionalized multi-walled carbon nanotubes (MWNTs). The biosensor electrode is designated as MWNT(SH)-Au/Chi-IL/ChOx.

Electrochemical detection of celecoxib at a polyaniline grafted multiwall carbon nanotubes modified electrode.

A modified electrode is fabricated by grafting polyaniline (PANI) chains onto multiwall carbon nanotubes (MWNTs) and utilized for the adsorptive reduction of celecoxib (CEL). PANI-g-MWNTs modified electrode appreciably enhances the sensitive detection of CEL in extremely lower concentrations (1x10(-11)M). Square wave stripping voltammogram (SWSV) shows a reduction peak at -1.

Synthesis and characterization of processable multi-walled carbon nanotubes-sulfonated polydiphenylamine graft copolymers.

Water soluble and processable nanocomposites composed of multi-walled carbon nanotubes (MWNTs) and poly(diphenylamine sulfonic acid) (PDPASA) are synthesized and characterized. Two types of methodologies are adopted. MWNTs are covalently functionalized with 2,5-diaminobenzene sulfonic acid (DABSA) and further in situ polymerized with diphenylamine-4-sulfonic acid (DPASA).

Fabrication of a gold nanoparticles decorated carbon nanotubes based novel modified electrode for the electrochemical detection of glucose.

A modified electrode based on gold nanoparticles decorated multiwall carbon nanotubes (MWNTs), MWNT-Au(nano)-ME is fabricated. MWNTs are functionalized with 4-aminothiophenol and coated over the glassy carbon electrode. Further, Au nanoparticles are deposited into MWNTs coated GC electrode by electrochemical reduction of HAuCl4.

Novel method to prepare polystyrene-based monolithic columns for chromatographic and electrophoretic separations by microwave irradiation.

Microwave irradiation can provide a viable alternative to the traditional means such as ultraviolet light and thermal initiation for the preparation of monolithic capillary columns. Polystyrene-based monolithic stationary phases were prepared in situ in fused-silica capillaries and simultaneously in vials. The column permeability, electrophoretic and chromatographic behavior were evaluated using pressure-assisted capillary electrochromatography (pCEC), capillary electrochromatography (CEC) and low pressure liquid chromatography (LPLC).

Self-assembly directed synthesis of poly(ortho-toluidine)-metal(gold and palladium) composite nanospheres.

Poly(ortho-toluidine) (POT)-gold (Au) and palladium (Pd) composite nanospheres were successfully synthesized by the reaction of o-toluidine with the corresponding metal (Au or Pd) colloidal solution through self-assembly process in the presence of dodecylbenzenesulfonic acid (DBSA), which acts as both a dopant and surfactant, and ammonium peroxydisulfate as an oxidizing agent. The composites (POT-DBSA/Au or Pd) were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, UV-Visible (UV-Vis) spectroscopy, and electrical conductivity measurements. TEM images of the nanocomposites reveal that metal (Au or Pd) nanoparticles were well dispersed on POT spheres.

Enhanced electrochemical detection of ketorolac tromethamine at polypyrrole modified glassy carbon electrode.

A glassy carbon electrode modified with a coating of polypyrrole (Ppy) exhibited an attractive performance for the detection and determination of a non-steroidal and non-narcotic analgesic compound, ketorolac tromethamine (KT). Cyclic voltammetry, differential pulse and square wave voltammetry were used in a combined way to identify the electrochemical characteristics and to optimize the conditions for detection. For calibrating and estimating KT, square-wave voltammetry was mainly used.

Electrochemical determination of dopamine and ascorbic acid at a novel gold nanoparticles distributed poly(4-aminothiophenol) modified electrode.

A modified electrode is fabricated by embedding gold nanoparticles into a layer of electroactive polymer, poly(4-aminothiophenol) (PAT) on the surface of glassy carbon (GC) electrode. Cyclic voltammetry (CV) is performed to deposit PAT and concomitantly deposit Au nanoparticles. Field emission transmission electron microscopic image of the modified electrode, PAT-Au(nano)-ME, indicates the presence of uniformly distributed Au nanoparticles having the sizes of 8-10nm.

Nanostructuring of poly(diphenylamine) inside the galleries of montmorillonite organo clay through self-assembly approach.

Hollow spheres of poly(diphenylamine) (PDPA) was prepared by confining PDPA in the galleries of montmorillonite organo clay modified with organoammonium cations (MMT). At first instant, diphenylamine (DPA) was loaded into the galleries of MMT and subjected to subsequent oxidative polymerization to form PDPA. beta-naphthalene sulfonic acid (NSA) was used as medium to influence self-assembly of DPA inside the galleries of MMT.

Fabrication and electrocatalysis of self-assembly directed gold nanoparticles anchored carbon nanotubes modified electrode.

A self-assembly directed approach was adopted to modify glassy carbon electrode (GC) with gold nanoparticles incorporation and the electrocatalytic performance of self-assembly modified electrode, GC/SA-Au-ME was critically evaluated for the oxidation of ascorbic acid (AA). The modification involves the dispersion of multi-wall carbon nanotube (MWNT) and an inclusion complex, beta-cyclodextrin-4-aminothiophenol on the surface of GC electrode in the presence of cetyltrimethylammonium bromide (CTAB). Gold nanoparticles were deposited into the self-assembled sites to fabricate the modified electrode, GC/SA-Au-ME.