Aggregation-free optical and colorimetric detection of Hg(II) with M13 bacteriophage-templated Au nanowires.

An optical and colorimetric biosensor comprising gold nanowires (Au NWs) templated with genetically engineered M13 bacteriophages expressing a specific Au binding peptides tyrosine-glutamic acid-glutamic acid-glutamic acid (Y3E) is fabricated by silver nitrate and surfactant-mediated biomineralization process. The diameter of the Y3E-Au NWs is around 10 nm and an oriented growth mechanism is identified for the continuous growth of the NWs by interconnecting M13 bacteriophages. The flexible Au NWs have formed an enriched Hg(II) binding sites on its surface and the surface-coated silver nanophase functions as a receptor for more efficient Hg(II) binding.

Hematite/M (M = Au, Pd) Catalysts Derived from a Double-Hollow Prussian Blue Microstructure: Simultaneous Catalytic Reduction of - and -Nitrophenols.

Present study deals with hematite/M (M = Au, Pd) catalysts converted from a double-hollow Prussian blue microstructure (DHPM). The unique Prussian blue (PB) microstructure (MS) is prepared by a template-free solvothermal synthetic route in a single-step reaction. An amine-functionalized silicate sol-gel matrix (SSG) has served as the structure-directing agent cum stabilizer for making DHPM.

M13 Virus-Incorporated Biotemplates on Electrode Surfaces To Nucleate Metal Nanostructures by Electrodeposition.

We report a virus-incorporated biological template (biotemplate) on electrode surfaces and its use in electrochemical nucleation of metal nanocomposites as an electrocatalytic material for energy applications. The biotemplate was developed with M13 virus (M13) incorporated in a silicate sol-gel matrix as a scaffold to nucleate Au-Pt alloy nanostructures by electrodeposition, together with reduced graphene oxide (rGO). The phage when engineered with Y3E peptides could nucleate Au-Pt alloy nanostructures, which ensured adequate packing density, simultaneous stabilization of rGO, and a significantly increased electrochemically active surface area.

Gold dendrites Co-deposited with M13 virus as a biosensor platform for nitrite ions.

We developed a biosensor for nitrite ion on an electrode surface modified with M13 viruses and gold nanostructures. Gold dendritic nanostructures (Au-DNs) are electrochemically co-deposited from 4E peptides engineered M13 virus (M13) mixed electrolyte on to the ITO electrode. The M13 could specifically nucleate Au precursor (Gold (III) chloride), which enable the efficient growth of dendritic nanostructures, whereas such dendritic structures were not obtained in the presence of wild-type and Y3E peptides engineered M13 viruses.

In Situ Growth of Prussian Blue Nanostructures at Reduced Graphene Oxide as a Modified Platinum Electrode for Synergistic Methanol Oxidation.

Herein, we report a facile synthetic strategy for the in situ growth of Prussian blue nanostructures (PB NSs) at the amine-functionalized silicate sol-gel matrix (TPDT)-RGO composite via the electrostatic interaction. Subsequently, Pt nanostructures are electrodeposited onto the preformed ITO/TPDT-RGO-PB electrode to prepare the RGO/PB/Pt catalyst. The significance of the present method is that the PB NSs are in situ grown by interconnecting the RGO layers, leading to 3D cage-like porous nanostructure.

Silver nanoparticles embedded in cyclodextrin-silicate composite and their applications in Hg(II) ion and nitrobenzene sensing.

Different synthetic routes were described to prepare silver (Ag) nanoparticles (NPs) embedded in an amine functionalized silicate sol-gel matrix (TPDT) by employing different combination of reagents such as silicate sol-gel (TPDT), β-cyclodextrin (CD)-TPDT, TPDT-surfactant (BDAC), CD-TPDT-BDAC and CD-TPDT-BDAC/ascorbic acid (AA). The spectral and colorimetric detection of Hg(II) ions were carried out using the Ag NPs which showed a significant blue shift in the surface plasmon resonance (SPR) band upon the addition of Hg(II) ions. It was found that the addition of optimum level of Hg(II) ions into the Ag NPs completely quenched the SPR band and deformed the shape of the Ag NPs due to the formation of anisotropic Ag amalgam crystals (AgHg).