Selective Amplification of Plasmonic Sensor Signal for Cortisol Detection Using Gold Nanoparticles

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Cortisol is a crucial biomarker for stress and various health conditions.
• Accurate and real-time cortisol determination is essential for clinical diagnostics.
• Existing detection methods may lack sensitivity or require complex sample preparation.

Purpose of the Study:

• To develop a highly sensitive and selective plasmonic sensor for real-time cortisol detection.
• To utilize gold nanoparticles (AuNP) for signal amplification in the sensor.
• To evaluate the sensor's performance in both aqueous and complex biological solutions.

Main Methods:

• Fabrication of a cortisol-imprinted polymer on a sensor surface.
• Modification of the sensor with gold nanoparticles (AuNP-MIP).
• Characterization using atomic force microscopy and contact angle measurements.
• Kinetic analysis and validation with High-Performance Liquid Chromatography (HPLC).

Main Results:

• The AuNP-MIP sensor demonstrated a wide detection range (0.01-100 ppb) and a low limit of detection (0.0087 ppb).
• High imprinting efficiency (k' = 9.67) was achieved compared to non-imprinted sensors.
• Excellent correlation coefficient (R² = 0.97) indicated reliable kinetic analysis.
• The sensor showed effective performance in complex solutions.

Conclusions:

• The developed gold nanoparticle-modified cortisol-imprinted plasmonic sensor provides a sensitive and efficient platform for real-time cortisol monitoring.
• The use of AuNPs significantly enhances signal amplification, leading to improved detection capabilities.
• This sensor technology holds promise for improved diagnostic tools in clinical and research settings.