Buildup of ultrathin multilayer films by a self-assembly process: III. Consecutively alternating adsorption of anionic and cationic polyelectrolytes on charged surfaces

Decher, Gero; Hong, Jong‐Dal; Schmitt, Johannes

doi:10.1016/0040-6090(92)90417-a

Cited by 2,805 publications

(2,077 citation statements)

References 9 publications

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“…[15][16][17][18][19] A detail understanding of the MEF and its distance dependence nature is vital for its potential application in biomedical sensing. [20][21][22] Layer-by-layer (LbL) assembly [23][24][25][26][27][28][29][30][31][32][33][34][35][36] is based on the sequential adsorption of polycations and polyanions from dilute aqueous solution onto a solid substrate as a consequence of the electrostatic interaction and complex formation between oppositely charged polyelectrolytes. Starting from a functionalized solid substrate, it is possible to adsorb a variety of charged species ranging from polyelectrolytes, nanoparticles, and ionic dyes to many biological agents such as viruses, proteins, and DNA.…”

Section: Introductionmentioning

confidence: 99%

Polyelectrolyte Layer-by-Layer Assembly To Control the Distance between Fluorophores and Plasmonic Nanostructures

2007

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In the past several years we have demonstrated the metal-enhanced fluorescence (MEF) and the significant changes in the photophysical properties of fluorophores in the presence of metallic nanostructures and nanoparticles. MEF is largely dependent on several factors, such as chemical nature, size, shape of the nanostructure, and its distance from the interrogating fluorophore. Herein, we elucidate the potential of layer-by-layer (LbL) assembly to understand the distance dependence nature of MEF from sulforhodamine B (SRB) assembled on the plasmonic nanostructured surfaces [in the form of Silver Islands films (SIFs)]. The varied proximity of fluorophores from the SIF surfaces was controlled by constructing different numbers of alternate layers of poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH). An anionic laser dye SRB could be electrostatically attached to the positively charged PAH layer. Orientation of the SRB probe molecule adsorbed in PSS/PAH-layered assembly was determined by polarized absorption spectroscopy. The observed tilt angle of the probe transition dipole moment with respect to the surface normal was 40°. Our results show that MEF is indeed distance-dependent. Accordingly, we observed a maximum of a ~6-fold increase in the fluorescence intensity from a monolayer of the SRB at a distance of ~9 nm from the metal-nanostructured surface, with the enhancement decreasing down to ~1.5-fold at about a 30 nm separation distance. Consistently, the minimum lifetimes were about 4-fold shorter than those on glass slides without silver, with the lifetimes being about nearly the same for 15 layers of the PSS/PAH assembly. The intensity-time decays were analyzed with a lifetime distribution model to underpin the distance effect on the metal-fluorophore interaction in the nanometric range. The present study provides improved understanding of the interaction between plasmonic nanostructures and fluorophores and, more importantly, their distance dependence nature, where we used a robust, easy, and inexpensive alternate electrostatic LbL assembly as a bottom-up nanofabrication technique to control the probe distance from the surface.

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Section: Introductionmentioning

confidence: 99%

Polyelectrolyte Layer-by-Layer Assembly To Control the Distance between Fluorophores and Plasmonic Nanostructures

2007

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“…Sammon's mapping and IDMAP as strategies to plot impedance data from sensors made with layer-by-layer (LbL) [91] films in order to detect phytic acid in solution. The real and imaginary components of the impedance were analyzed concomitantly.…”

Section: Moraes Et Al [8] Comparedmentioning

confidence: 99%

Information Visualization to Enhance Sensitivity and Selectivity in Biosensing

Oliveira¹,

Pavinatto²,

Constantino³

et al. 2012

Biointerphases

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An overview is provided of the various methods for analyzing biosensing data, with emphasis on information visualization approaches such as multidimensional projection techniques. Emphasis is placed on the importance of data analysis methods, with a description of traditional techniques, including the advantages and limitations of linear and non-linear methods to generate layouts that emphasize similarity/dissimilarity relationships among data instances. Particularly important are recent methods that allow processing high-dimensional data, thus taking full advantage of the capabilities of modern equipment. In this area, now referred to as e-science, the choice of appropriate data analysis methods is crucial to enhance the sensitivity and selectivity of sensors and biosensors. Two types of systems deserving attention in this context are electronic noses and electronic tongues, which are made of sensor arrays whose electrical or electrochemical responses are combined to provide “finger print” information for aromas and tastes. Examples will also be given of unprecedented detection of tropical diseases, made possible with the use of multidimensional projection techniques. Furthermore, ways of using these techniques along with other information visualization methods to optimize biosensors will be discussed.

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“…glass, ceramics, metals, wood, plastics and so on [1][2][3][4] of any size and topology [5,6]. In essence, the process is based on the electrostatic attraction of opposite charges and can be used with various reagents such as polymers [7], nanoparticles [8,9], metals [10], dyes [11,12], quantum dots [13], nanotubes [14], biomolecules like enzymes [15], proteins [16], etc.…”

Section: Introductionmentioning

confidence: 99%

Wavelength dependent pH optical sensor using the layer-by-layer technique

Raoufi

Surre

Sun

et al. 2012

Sensors and Actuators B: Chemical

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This is the unspecified version of the paper.This version of the publication may differ from the final published version. Permanent repository link AbstractIn this work, the design and characteristics of a wavelength-dependent pH optical sensor have been studied. To create the sensor itself, brilliant yellow (BY) as a pH indicator and poly (allylamine hydrochloride) [PAH] as a cross-linker have been deposited on the end of a bare silica core of an optical fibre by use of a 'layer-by-layer' technique. In the experiments carried out to characterize the sensor, it was observed that the value of pK a (the dissociation constant) of the thin film is dependent both on the outer layer and the number of bilayers. A heat treatment process was applied to the sensor to reduce the effect on the deposited layers during the testing of the probe. As a result of these series of experiments, it could be concluded that the probe design on which were deposited structured layers comprising six double layers of (PAH/BY) showed the best sensitivity for a pH range from 6.80 to 9.00 (with an accuracy of ±0.20) and showing an average wavelength shift of 4.65 nm per 0.2 pH units, while the concentration of the BY and the PAH solutions was maintained as 0.25mM and 2.5mM respectively.

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Buildup of ultrathin multilayer films by a self-assembly process: III. Consecutively alternating adsorption of anionic and cationic polyelectrolytes on charged surfaces

Cited by 2,805 publications

References 9 publications

Polyelectrolyte Layer-by-Layer Assembly To Control the Distance between Fluorophores and Plasmonic Nanostructures

Polyelectrolyte Layer-by-Layer Assembly To Control the Distance between Fluorophores and Plasmonic Nanostructures

Information Visualization to Enhance Sensitivity and Selectivity in Biosensing

Wavelength dependent pH optical sensor using the layer-by-layer technique

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