Comparative studies between synthetic routes of SiO2@Au composite nanoparticles

Zhang, Lu; Feng, Yusheng; Wang, Liying; Zhang, Junyan; Chen, Meng; Qian, Dong−Jin

doi:10.1016/j.materresbull.2006.11.019

Cited by 22 publications

(20 citation statements)

References 34 publications

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“…After a few minutes, the white precipitate was washed, centrifuged, and dispersed in distilled water, until the supernatant solution turned neutral, the opaque and white silica sol-gel is formed [28].…”

Section: Apparatusmentioning

confidence: 99%

Enzyme biosensor based on the immobilization of HRP on SiO2/BSA/Au composite nanoparticles

Yuan

Zhuo

et al. 2010

Appl Biochem Biotechnol

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In this work, an enzyme biosensor based on the immobilization of horseradish peroxidase (HRP) on SiO₂/BSA/Au/thionine/nafion-modified gold electrode was fabricated successfully. Firstly, nafion was dropped on the surface of the gold electrode to form a nafion film followed by chemisorption of thionine (Thi) as an electron mediator via the ion-exchange interaction between the Thi and nafion. Subsequently, the SiO₂/BSA/Au composite nanoparticles were assembled onto Thi film through the covalent bounding with the amino groups of Thi. Finally, HRP was immobilized on the SiO₂/BSA/Au composite nanoparticles due to the covalent conjugation to construct an enzyme biosensor. The surface topographies of the SiO₂/BSA/Au composite nanoparticles were investigated by using scanning electronic microscopy. The stepwise self-assemble procedure of the biosensor was further characterized by means of cyclic voltammetry and chronoamperometry. The enzyme biosensor showed high sensitivity, good stability and selectivity, a wide linear response to hydrogen peroxide (H₂O₂) in the range of 8.0 x 10⁻⁶ ~3.72 x 10⁻³ mol/L, with a detection limit of 2.0 x 10⁻⁶ mol/L. The Michaelies-Menten constant K(app)(M) value was estimated to be 2.3 mM.

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Section: Apparatusmentioning

confidence: 99%

Enzyme biosensor based on the immobilization of HRP on SiO2/BSA/Au composite nanoparticles

Yuan

Zhuo

et al. 2010

Appl Biochem Biotechnol

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“…From the literature, it is seen that a variety of approaches have been used to prepare Au-'Si' composites . There are papers dedicated to adsorbing Au NPs inside [2][3][4][5][6][7][8][9][10][11], outside [12][13][14][15][16][17][18][19][20][21][22][23][24][25] or both sides [25][26][27] of 'Si' spheres. The surface of the 'Si' or template would usually be chemically modified to allow the assembly of Au NPs or AuCl the surfaces of the spheres [29].…”

Section: Introductionmentioning

confidence: 99%

“…There are three main routes for preparing Au-coated 'Si' hollow spheres, (1) direct deposition of Au NPs by mixing two colloids [12][13][14][15][16][17][18], (2) in situ reduction of HAuCl 4 [21] or (3) deposition of Au NPs that act as 'seeds' for the further growth of the Au shell from exposure to HAuCl 4 (aq) [19,22,24]. The disadvantage of some of the current methods using route (1) is that the 'Si' sphere is repeatedly exposed to colloidal Au and the unreacted Au NPs are washed out in order to gain dense coverage.…”

Section: Introductionmentioning

confidence: 99%

“…This process can be time consuming and expensive. Some studies have shown that Au NP coverage on the outer surface of 'Si' can be improved when the pH of the reaction is adjusted [13][14][15]19,24]. Furthermore, Osterloh et al [15] showed that citrate-stabilised Au NPs desorb from amine functionalised 'Si' spheres when the Au-'Si' composite is exposed to dilute HCl or KBr (0.1 M).…”

Section: Introductionmentioning

confidence: 99%

“…Papers demonstrating high single Au NP coverage concern 'Si' particle sizes in the range 100-500 nm [13][14][15]19]. For large particles (41 mm) the coverage of the 'Si' surface is incomplete, unless the Au nanoshell is formed via seeded growth [19,22,24].…”

Section: Introductionmentioning

confidence: 99%

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One-step deposition of Au nanoparticles onto chemically modified ceramic hollow spheres via self-assembly

Begum

Jones

Lynch

et al. 2012

Journal of Experimental Nanoscience

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A concentrated citrate-stabilised Au nanoparticle (NP) colloid has been prepared using a modified Frens procedure, and characterised using transmission electron microscopy (TEM) and UV-Vis absorption spectroscopy. The average diameter determined from TEM images of concentrated Au NPs (16.57 AE 0.65 nm) is similar to the diameter reported by Frens (16 nm). The surface plasmon band of the concentrated Au NPs UV-Vis spectrum has a max at 522 nm. Bare silica ('Si') and iron-'Si' hollow microsphere surfaces have been functionalised with amino groups using the surfactant 3-aminopropyltrimethoxysilane (APTMS). The Au NPs have been assembled onto the APTMS-treated hollow spheres by dispersing a colloid of Au NPs into a suspension of hollow spheres at pH 4.5 (2 h). The volume ratio of Au NPs: hollow spheres was adjusted until maximum deposition could be achieved in a single step. TEM micrographs of ultrathin (80-100 nm) ultramicrotome sections through the Au NP-coated hollow spheres reveal that a single layer of Au NPs is mainly distributed on (1) the external side of the shell wall for 'Si' and (2) both sides of the shell wall for iron-'Si'. UV-Vis absorption spectra of the Au NP-coated hollow spheres show that the surface plasmon band shifts (524-613 nm) and broadens as the density of Au NPs is increased on the shell surface.

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Morphology‐controllable synthesis of ZnO nano‐/micro‐ structures by a solvothermal process in ethanol solution

Zhang

Sui

et al. 2013

Crystal Research and Technology

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Flower‐like ZnO nanostructures assembled by nanorods with bimodal size distribution have been synthesized by a solvothermal process in NaOH‐Et system. Various effects of the solvothermal parameters and assistant additives on the morphologies of ZnO nanostructures have been investigated. The directing effect of chloride ions have been observed in the formation of highly symmetrical 3D ZnO nanostructures. A possible mechanism has been proposed to explain the formation of ZnO nanoflowers in NaOH‐Et system. A strong near‐UV emission band centered at around 396 nm is observed in the photoluminescence spectrum of flower‐like ZnO nanostructures, indicating of their high crystal quality.

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Comparative studies between synthetic routes of SiO2@Au composite nanoparticles

Cited by 22 publications

References 34 publications

Enzyme biosensor based on the immobilization of HRP on SiO2/BSA/Au composite nanoparticles

Enzyme biosensor based on the immobilization of HRP on SiO2/BSA/Au composite nanoparticles

One-step deposition of Au nanoparticles onto chemically modified ceramic hollow spheres via self-assembly

Morphology‐controllable synthesis of ZnO nano‐/micro‐ structures by a solvothermal process in ethanol solution

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