Electroactive Nanostructured Membranes (ENM): Synthesis and Electrochemical Properties of Redox Mediator‐Modified Gold Nanoparticles Using a Dendrimer Layer‐by‐Layer Approach

Crespilho, Frank N.; Ghica, Mariana Emilia; Zucolotto, Valtencir; Nart, Francisco Carlos; Oliveira, Osvaldo N.; Brett, Christopher M.A.

doi:10.1002/elan.200603775

Cited by 33 publications

(27 citation statements)

References 27 publications

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“…Assuming that the ferrocenyl guests immobilized on the smallest size dendrimers might be confined more closely than those borne on the larger dendrimers, it could be expected that the largest adsorbateadsorbate repulsive interactions should be observed for the former situation and decrease gradually as an inverse function of the dendritic generation. [29][30][31][32][33] Table 2 gives the values of K, G t=0 ads , and a that were obtained by fitting the Frumkin-isotherm curves to the data in Figure 4. As it can be seen from the fitted values, the association constant K for adsorption onto the immobilized Fc varied inversely with the dendritic size, and G t=0 ads became more negative.…”

Section: Binding Of CD With Fc Tethered To the Dendrimer Filmsmentioning

confidence: 99%

Electrochemical study of β-Cyclodextrin binding with ferrocene tethered onto a gold surface via PAMAM dendrimers

Bustos¹,

Manríquez²,

Juaristi³

et al. 2008

J. Braz. Chem. Soc.

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Este artigo descreve a fixação de ferrocenos (Fc) sobre eletrodos policristalinos de ouro, por filmes dendrímeros de poliamidoamina (PAMAM). A superfície eletroativa fornece uma rota viável para investigar quantitativamente a ligação do ferroceno com a ciclodextrina (CD). Em particular, as medidas eletroquímicas, revelam o efeito das interações adsorção-adsorção sobre a constante de associação K, na interface eletrodo-eletrólito, durante a formação do complexo de 1:1 Os resultados obtidos a partir da investigação da isoterma de adsorção de Frumkin indicam que as interações podem ter um forte impacto na afinidade do CD com as superfícies do ferrocenil modificado, estudadas aqui. A técnica apresentada pode ser útil para investigar outras reações de ligação entre hóspede-hospedeiro. This paper describes the tethering of ferrocene (Fc) onto polycrystalline gold electrodes by immobilized polyamidoamine (PAMAM) dendrimers films. The resulting electroactive surface provides a viable route for investigating quantitatively the host-guest binding of ferrocene with cyclodextrin (CD). In particular, electrochemical measurements reveal the effect of adsorbateadsorbate interactions on the association constant K for the formation of the 1:1 CD Fc complex at the electrode-electrolyte interface. The results obtained from fitting the Frumkin isotherm to the adsorption data indicate that adsorbate-adsorbate interactions can have a strong impact on the CD affinity for the ferrocenyl-modified surfaces studied here. The technique presented may be useful for investigating other host-guest binding reactions.

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Section: Binding Of CD With Fc Tethered To the Dendrimer Filmsmentioning

confidence: 99%

Electrochemical study of β-Cyclodextrin binding with ferrocene tethered onto a gold surface via PAMAM dendrimers

Bustos¹,

Manríquez²,

Juaristi³

et al. 2008

J. Braz. Chem. Soc.

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“…In previous work, three bilayers of PVS/PAMAM-Au was found to be the best configuration to prepare an ITO modified electrode, since 3-bilayer PVS/PAMAM-Au LbL films were found to possess high organisation and outstanding uniformity [8].…”

Section: Preparation Of An Electroactive Nanostructured Membrane (Enmmentioning

confidence: 99%

“…We previously showed that ITO-(PVS/PAMAM-Au) 3 structures are suitable for biosensors and electrocatalysis owing to their low capacitive and high Faradaic currents associated with low ohmic drop [8]. Electrodeposition by potential cycling of cobalt hexacyanoferrate onto ITO-(PVS/PAMAM-Au) 3 electrodes was carried out according to the optimised conditions in previous work [7,16].…”

Section: Preparation Of An Electroactive Nanostructured Membrane (Enmmentioning

confidence: 99%

“…In [8] and by comparing electrochemical impedance spectra of different electrodeposited metal hexacyanoferrate mediators, it was demonstrated that the charge-transfer at ITO-(PVS/PAMAMAu) 3 @Me electrodes is faster than at ITO-(PVS/PAMAM-Au) 3 , and the charge-transfer resistance using CoHCF is lower than for other hexacyanoferrates (e.g. CuHCF, FeHCF and NiHCF).…”

Section: Preparation Of An Electroactive Nanostructured Membrane (Enmmentioning

confidence: 99%

“…It was shown how one can benefit from combining the biocatalytic properties of the enzyme with the conductivity and electrocatalytic properties of gold nanoparticles. The strategy used consists in applying a new concept in nanoarchitecture: electroactive nanostructured membranes (ENM) with ITO-PVS/PAMAM-Au LbL electrodes [8], where indium tin oxide (ITO) is the electrode substrate and PVS is poly(vinylsulfonate), which alternates with PAMAM-Au (PAMAM containing gold nanoparticles) in the bilayer structure. A redox mediator (Me) is then electrodeposited around the Au nanoparticles to form an ITO-PVS/PAMAM-Au@Me system.…”

Section: Introductionmentioning

confidence: 99%

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Enzyme immobilisation on electroactive nanostructured membranes (ENM): Optimised architectures for biosensing

Crespilho

Ghica

Gouveia‐Caridade

et al. 2008

Talanta

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a b s t r a c tElectroactive nanostructured membranes have been produced by the layer-by-layer (LbL) technique, and used to make electrochemical enzyme biosensors for glucose by modification with cobalt hexacyanoferrate redox mediator and immobilisation of glucose oxidase enzyme. Indium tin oxide (ITO) glass electrodes were modified with up to three bilayers of polyamidoamine (PAMAM) dendrimers containing gold nanoparticles and poly(vinylsulfonate) (PVS). The gold nanoparticles were covered with cobalt hexacyanoferrate that functioned as a redox mediator, allowing the modified electrode to be used to detect H 2 O 2 , the product of the oxidase enzymatic reaction, at 0.0 V vs. SCE. Enzyme was then immobilised by cross-linking with glutaraldehyde. Several parameters for optimisation of the glucose biosensor were investigated, including the number of deposited bilayers, the enzyme immobilisation protocol and the concentrations of immobilised enzyme and of the protein that was crosslinked with PAMAM. The latter was used to provide glucose oxidase with a friendly environment, in order to preserve its bioactivity. The optimised biosensor, with three bilayers, has high sensitivity and operational stability, with a detection limit of 6.1 M and an apparent Michaelis-Menten constant of 0.20 mM. It showed good selectivity against interferents and is suitable for glucose measurements in natural samples.

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Dendrimer‐Based Sensors

2011

Chemosensors

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Electroactive Nanostructured Membranes (ENM): Synthesis and Electrochemical Properties of Redox Mediator‐Modified Gold Nanoparticles Using a Dendrimer Layer‐by‐Layer Approach

Cited by 33 publications

References 27 publications

Electrochemical study of β-Cyclodextrin binding with ferrocene tethered onto a gold surface via PAMAM dendrimers

Electrochemical study of β-Cyclodextrin binding with ferrocene tethered onto a gold surface via PAMAM dendrimers

Enzyme immobilisation on electroactive nanostructured membranes (ENM): Optimised architectures for biosensing

Dendrimer‐Based Sensors

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