Related Experiment Video
Updated: Jun 20, 2026
07:44
Synthesis of Wavelength-shifting DNA Hybridization Probes by Using Photostable Cyanine Dyes
Published on: July 6, 2016
J-aggregation of cyanine dyes by self-assembly
Rolf Steiger1, Raphaël Pugin, Jakob Heier
1Swiss Center for Electronics and Microtechnology (CSEM) Jaquet-Droz 1, CH-2002 Neuchâtel, Switzerland. rolf_steiger@bluewin.ch
Colloids and Surfaces. B, Biointerfaces
|September 15, 2009
Summary
Highly ordered surfaces enable J-aggregate formation via self-assembly. Dendrimers on nanoparticle coatings yield stable, size-controlled J-aggregates for optoelectronics and sensors.
Area of Science:
- Surface Science
- Materials Chemistry
- Nanotechnology
Background:
- Highly ordered surfaces with adsorptive states are crucial for J-aggregation.
- Nanometer-sized features like edges and corners of AgBr microcrystals act as nucleation sites.
- Surface iodide clusters on AgBr:I microcrystals also facilitate J-aggregation.
Purpose of the Study:
- To explore the role of various nucleating surfaces in J-aggregation by self-assembly.
- To investigate the use of dendrimers, monoatomic steps, and fullerene derivatives as nucleating agents.
- To achieve size-controlled and stable J-aggregates with enhanced optical properties.
Main Methods:
- Utilizing aprotic, apolar solvents for fullerene self-assembly.
- Employing polar solvents for dendrimer and monoatomic step self-assembly.
- Integrating dendrimers as nucleating agents within mesopores of metal oxide nanoparticle coatings.
Main Results:
- Reproducible formation of size-controlled and stable J-aggregates.
- Achieved high optical densities and strong fluorescence in J-aggregate films.
- Demonstrated successful molecular organization into J-aggregates using diverse nucleating surfaces.
Conclusions:
- Highly ordered surfaces are essential for controlled J-aggregation via self-assembly.
- Dendrimers, particularly when used with nanoparticle coatings, offer a robust method for creating high-performance J-aggregates.
- These J-aggregate films hold significant potential for applications in sensors, optoelectronics, lighting, and photovoltaics.
Related Concept Videos
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
01:32Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview
Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction mixture.