A mixed alkanethiol based immunosensor for surface plasmon field-enhanced fluorescence spectroscopy in serum

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensing Technology

Background:

• C-reactive protein (CRP) is a crucial biomarker for inflammatory conditions and cardiovascular diseases (CVD).
• Current detection methods like ELISA can be affected by interfering substances in serum, impacting accuracy.
• There is a need for robust, sensitive, and rapid analytical methods for CRP detection in complex biological samples.

Purpose of the Study:

• To develop a simple, sensitive, and interference-reduced immuno-based biosensor for C-reactive protein (CRP) detection in serum.
• To utilize surface plasmon field-enhanced fluorescence spectroscopy (SPFS) for enhanced detection sensitivity.
• To validate the biosensor's performance in authentic serum samples.

Main Methods:

• A non-competitive sandwich immunoassay format was employed.
• Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) was coupled with the immunoassay for signal amplification.
• The biosensor's performance, including limit of detection (LOD) and limit of quantification (LOQ), was evaluated using CRP-spiked buffer and human serum.

Main Results:

• The SPFS-enhanced biosensor achieved a limit of detection (LOD) of 0.016 μg mL⁻¹ and a limit of quantification (LOQ) of 0.049 μg mL⁻¹ in buffer.
• In serum samples, the biosensor demonstrated a low LOD of 0.026 μg mL⁻¹ and an LOQ of 0.08 μg mL⁻¹.
• These results indicate effective interference reduction and high sensitivity in a complex biological matrix.

Conclusions:

• The developed immuno-biosensor coupled with SPFS provides a sensitive and robust platform for CRP detection.
• The biosensor's ability to perform interference-reduced analysis in serum highlights its potential for clinical diagnostics.
• This technology is suitable for qualitative and semi-quantitative analysis of trace analytes in small volumes of bodily fluids.