Surface plasmon resonance-based immunoassay for human C-reactive protein.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunosensing

Background:

• Human C-reactive protein (CRP) is a crucial biomarker for inflammatory conditions, metabolic disorders, and infections.
• Existing methods for CRP detection can be time-consuming or lack the required sensitivity and stability for rapid clinical diagnostics.

Purpose of the Study:

• To develop and validate a rapid, highly-sensitive surface plasmon resonance (SPR)-based immunoassay (IA) for detecting human C-reactive protein (CRP).
• To establish an efficient and stable immobilization strategy for antibodies on SPR chips for improved assay performance.

Main Methods:

• Functionalization of gold-coated SPR chips using EDC-activated protein A/G and APTES.
• Oriented immobilization of anti-human CRP capture antibodies onto the functionalized SPR chip.
• Assay validation using CRP standards and spiked human blood, serum, and plasma samples.

Main Results:

• The developed SPR-based IA demonstrated high sensitivity for CRP detection, with a limit of detection (LOD) of 1.2 ng mL(-1) and a limit of quantification (LOQ) of 4.6 ng mL(-1) within the 1.2-80 ng mL(-1) range.
• The assay accurately detected CRP in various human biological matrices, including whole blood, serum, and plasma, with precision comparable to established methods.
• Antibody-bound SPR chips maintained functional activity for up to 10 weeks when stored at 4 °C, indicating enhanced assay stability and reduced analysis time.

Conclusions:

• A rapid and highly-sensitive SPR-based immunoassay for human CRP detection has been successfully developed and validated.
• The simplified antibody immobilization strategy offers a significant reduction in assay development time and improves the stability of the sensing platform.
• This SPR-based IA shows great potential for efficient and reliable CRP monitoring in clinical diagnostics.