A liquid crystal-based biosensor for sensitive detection of tumor necrosis factor-alpha

Area of Science:

• Biomedical Engineering
• Immunotechnology
• Materials Science

Background:

• Tumor Necrosis Factor-alpha (TNF-α) is a critical cytokine biomarker for inflammation.
• Elevated TNF-α levels in physiological fluids indicate various pathological conditions.
• Accurate and simple detection strategies for TNF-α are in high demand.

Purpose of the Study:

• To develop a sensitive liquid crystal (LC)-based biosensor for TNF-α detection.
• To establish an antigen-antibody reaction mechanism for TNF-α quantification.
• To validate the biosensor's performance using physiological fluid samples.

Main Methods:

• A sandwich assay utilizing capture antibodies (CAbs) and detection antibodies (DAbs) for TNF-α.
• Immobilization of CAbs on a surface to capture TNF-α/DAb complexes.
• Utilizing liquid crystals (LCs) whose orientation is disrupted by antigen-antibody binding.
• Visualizing LC orientational changes via polarized optical microscopy.

Main Results:

• Demonstrated a linear detection range of 5.00–500 pg/mL for TNF-α.
• Achieved a limit of detection (LOD) of 1.08 pg/mL and limit of quantification (LOQ) of 3.56 pg/mL.
• Reported high TNF-α recovery rates (97.1%–107%) in diluted saliva samples.

Conclusions:

• The developed LC-based biosensor provides a sensitive and accurate method for TNF-α detection.
• The biosensor's performance in saliva samples shows potential for clinical diagnostics.
• This approach offers a simple and visualizable strategy for biomarker quantification.