Related Experiment Video
Updated: Nov 12, 2025
14:11
Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
6.4K
Acridone and acridinium constructs with red-shifted emission
Anastasiia A Tikhomirova1, Kerry M Swift1, Richard A Haack1
1Applied Research and Technology, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois 60064, United States of America.
Methods and Applications in Fluorescence
|March 15, 2021
Summary
Researchers developed a novel acridinium-fluorescein chemiluminophore for enhanced diagnostic assays. This new construct, emitting at 530 nm, enables multicolor detection and improved chemiluminescent energy transfer studies.
Area of Science:
- Analytical Chemistry
- Biochemistry
- Organic Chemistry
Background:
- Acridinium derivatives are widely used as chemiluminescent labels in diagnostic assays.
- Current acridinium labels emit light in the 420-440 nm range.
- Development of novel chemiluminescent labels with red-shifted emission is crucial for advanced diagnostic applications.
Purpose of the Study:
- To introduce a novel acridinium-fluorescein construct with red-shifted emission at 530 nm.
- To synthesize and characterize acridone-fluorescein analogs for spectral property investigation.
- To study chemiluminescent energy transfer mechanisms and optimize diluent composition.
Main Methods:
- Synthesis of acridinium-fluorescein and acridone-fluorescein constructs with varying fluorescein isomers.
- Characterization of spectral properties (absorption, excitation, emission) and fluorescence lifetimes.
- Investigation of energy transfer efficiency and optimization of diluent composition to prevent dye aggregation.
Main Results:
- A novel acridinium-fluorescein chemiluminophore emitting at 530 nm was successfully synthesized.
- Acridone-fluorescein analogs exhibited similar spectral properties and fluorescence lifetimes.
- Nearly complete energy transfer from acridone to fluorescein was observed in the tandem constructs.
- Optimized diluent composition prevented dye aggregation in fluorescent acridone-fluorophore tandems.
Conclusions:
- Acridone-based dyes are valuable tools for studying chemiluminescent energy transfer and optimizing related acridinium-fluorophore tandems.
- The novel acridinium-fluorescein chemiluminophores enable red-shifted emission for advanced diagnostic assays.
- These labels are applicable for multicolor detection in clinical diagnostics, as demonstrated by a two-color HIV model immunoassay.
Related Concept Videos
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
3.3K
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...
3.3K
01:19Diazonium Group Substitution: –OH and –H
3.0K
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
3.0K
01:19Amines to Amides: Acylation of Amines
2.9K
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
2.9K
02:42Acidity of 1-Alkynes
10.5K
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
10.5K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.2K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.2K
01:37Super-resolution Fluorescence Microscopy
11.8K
Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been...
11.8K