Surface plasmon resonance immunosensor for cortisol and cortisone determination.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunosensing

Background:

• Cortisol and cortisone are key biomarkers for various physiological and pathological conditions.
• Accurate and rapid detection methods are crucial for clinical diagnostics and forensic analysis.
• Existing methods may lack the required speed, sensitivity, or cost-effectiveness.

Purpose of the Study:

• To develop and validate a surface plasmon resonance (SPR)-based immunosensor for real-time quantification of cortisol and cortisone.
• To evaluate the performance characteristics of the immunosensor, including sensitivity, specificity, and stability.
• To compare the immunosensor's performance against a reference method for real-world sample analysis.

Main Methods:

• Utilized a surface plasmon resonance (SPR) platform for label-free detection.
• Employed polycarboxylate-hydrogel coatings for antibody immobilization, enhancing sensor stability and reducing non-specific binding.
• Validated the immunosensor using urine and saliva samples and compared results with liquid chromatography/tandem mass spectrometry (LC-MS/MS).

Main Results:

• The SPR immunosensor demonstrated high sensitivity, specificity, and reproducibility for cortisol and cortisone detection.
• The hydrogel coating effectively prevented non-specific binding, ensuring assay reliability.
• Excellent correlation was observed between the immunosensor results and the reference LC-MS/MS method.
• Achieved a detection limit below 10 µg/L, suitable for clinical and forensic applications.

Conclusions:

• The developed SPR immunosensor provides a simple, rapid, and sensitive platform for cortisol and cortisone analysis.
• The hydrogel-based antibody immobilization strategy enhances sensor performance and robustness.
• This technology holds significant potential for routine clinical and forensic testing of cortisol and cortisone levels.