Immunoassays with time-resolved fluorescence spectroscopy: principles and applications

Area of Science:

• Analytical Chemistry
• Biochemistry
• Immunology

Background:

• Immunoassays are crucial diagnostic tools.
• Conventional fluorometry in immunoassays has limitations.
• Time-resolved fluorescence spectroscopy (TRFS) offers enhanced sensitivity and reduced background noise.

Purpose of the Study:

• To review the application of TRFS in immunoassays.
• To highlight the advantages of TRFS over conventional methods.
• To discuss the suitability of lanthanide chelates, particularly Europium (Eu3+), as fluorescent labels.

Main Methods:

• Discussion of time-resolved fluorometers and phase-resolved fluorometry principles.
• Critical analysis of commercially available TRFS assay formats.
• Exploration of assay designs utilizing Eu3+ and novel Eu3+ chelates.

Main Results:

• TRFS provides superior performance compared to conventional fluorometry.
• Eu3+ chelates are identified as optimal labels due to their photophysical properties.
• Commercial TRFS instruments and assay principles are evaluated for their merits and drawbacks.

Conclusions:

• TRFS, especially with Eu3+ labels, represents a significant advancement in immunoassay technology.
• The review provides insights into current assay designs and future directions.
• Further development in Eu3+ chelates and assay formats is anticipated to enhance immunoassay capabilities.