Surface plasmon resonance-based immunoassay for human fetuin A

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biochemistry

Background:

• Human fetuin A (HFA) is a significant biomarker for atherosclerosis and hepatocellular carcinoma.
• Accurate and sensitive detection of HFA is crucial for early diagnosis and monitoring of these diseases.
• Existing immunoassay methods may lack the required sensitivity, speed, or cost-effectiveness.

Purpose of the Study:

• To develop a highly sensitive and rapid surface plasmon resonance (SPR)-based immunoassay (IA) for human fetuin A (HFA).
• To establish a novel and simplified antibody immobilization technique for enhanced assay performance and reusability.
• To validate the developed SPR IA for HFA detection in biological samples like blood and plasma.

Main Methods:

• A novel antibody immobilization strategy using 3-aminopropyltriethoxysilane (APTES) on a gold-coated SPR chip.
• Dispensing and incubation of anti-HFA capture antibody on the prepared SPR chip.
• Detection of HFA using the developed SPR IA and comparison with ELISA for validation.

Main Results:

• The SPR IA demonstrated high sensitivity for HFA detection, with a limit of detection of 0.7 ng mL⁻¹ and sensitivity of 1 ng mL⁻¹ within the 0.3-20 ng mL⁻¹ range.
• The simplified antibody immobilization procedure was 5-fold faster than conventional methods and ensured leach-proof antibody binding.
• The SPR chip exhibited excellent reusability and stability, retaining 82% activity after 4 months of storage.
• SPR IA results for HFA in diluted human whole blood and plasma showed good agreement with a commercial ELISA kit.

Conclusions:

• The developed SPR-based immunoassay provides a highly sensitive, rapid, and cost-effective method for HFA detection.
• The novel antibody immobilization technique enhances assay efficiency and allows for chip reusability, reducing costs.
• This SPR IA is a promising tool for the clinical diagnosis and monitoring of atherosclerosis and hepatocellular carcinoma.