Electrochemical immunoassays

Area of Science:

• Analytical Chemistry
• Biotechnology
• Clinical Diagnostics

Background:

• Immunoassays (IA) leverage specific antigen-antibody interactions for analysis.
• Established methods like Radioimmunoassays (RIA), fluorescence immunoassays (FIA), and enzyme immunoassays (EIA) are common in diagnostics.
• Electrochemical immunoassays are emerging as viable alternatives for point-of-care (POC) devices, particularly for optically challenging samples.

Purpose of the Study:

• To provide an overview of electrochemical immunoassay principles.
• To explore the potential of amperometric transducers for sensitive and rapid detection.
• To discuss an indirect competitive electrochemical immunoassay for nanomolar creatinine determination and address sensor regeneration challenges.

Main Methods:

• Review of established and emerging electrochemical immunoassay techniques.
• Focus on potentiometric, capacitive, and amperometric transducers.
• Discussion of competitive and noncompetitive assay formats using redox or enzyme labels.

Main Results:

• Amperometric transducers are preferred for electrochemical immunoassays due to fast detection, wide linear range, and low detection limits.
• Electrochemical methods offer advantages over optical methods for opaque or optically dense matrices.
• An indirect competitive electrochemical immunoassay shows potential for nanomolar creatinine determination.

Conclusions:

• Electrochemical immunoassays, particularly amperometric ones, are highly promising for developing advanced point-of-care diagnostic devices.
• These methods offer superior performance for specific analytes and complex sample types.
• Addressing challenges like sensor regeneration is key to the widespread adoption of electrochemical immunoassays.