Development of solid-phase chemiluminescence immunoassays for digoxin comparing flow injection and sequential...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Clinical Diagnostics

Background:

• Digoxin is a critical medication for heart conditions, requiring precise therapeutic drug monitoring.
• Existing immunoassays for digoxin may face limitations in speed, precision, or automation.
• Acridinium chemiluminescence offers high sensitivity for biomarker detection.

Purpose of the Study:

• To develop and compare two instrumental approaches for a competitive solid-phase immunoassay for digoxin.
• To evaluate the performance of a sequential injection technique against a flow injection analysis system.
• To optimize the assay for speed, precision, and sensitivity.

Main Methods:

• Development of a solid-phase immunoassay using immobilized antibodies in a flow cell.
• Comparison of a continuous flow injection analysis system with a novel sequential injection technique.
• Utilizing an acridinium chemiluminescence detection system for signal generation.

Main Results:

• The sequential injection technique demonstrated higher precision (2.16–5.5% RSD) compared to flow injection analysis.
• Total assay time, including regeneration, was under 8 minutes using the sequential injection method.
• Both techniques achieved a low femtomole detection limit for digoxin.

Conclusions:

• The sequential injection technique provides a precise, rapid, and sensitive method for digoxin quantification.
• This immunoassay system is suitable for high-throughput clinical diagnostics.
• The acridinium chemiluminescence system enhances the sensitivity of digoxin detection.