Biosensor based on hydrogel optical waveguide spectroscopy for the detection of 17β-estradiol

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Sensitive hormone detection is crucial for diagnostics, quality control, and environmental monitoring.
• Existing methods like surface plasmon resonance (SPR) have limitations in sensitivity and binding capacity.
• 17β-estradiol (E2) is a key hormone requiring precise quantification.

Purpose of the Study:

• To develop a novel label-free biosensor for sensitive hormone detection.
• To utilize hydrogel optical waveguide spectroscopy (HOWS) for enhanced performance.
• To achieve a lower detection limit for 17β-estradiol (E2) compared to SPR.

Main Methods:

• Fabrication of a biosensor using a carboxylated poly(N-isoproprylacrylamide) (PNIPAAm) terpolymer hydrogel on a metallic surface.
• Implementation of hydrogel optical waveguide spectroscopy (HOWS) for signal transduction.
• Utilizing the Kretschmann configuration of attenuated total reflection (ATR) for optical excitation and interrogation of waveguide modes.

Main Results:

• The HOWS biosensor demonstrated a high binding capacity and good anti-fouling properties.
• Achieved a detection limit of 50 pg/ml for 17β-estradiol (E2).
• The achieved detection limit was seven times better than that of a conventional SPR biosensor, indicating an improved figure of merit.

Conclusions:

• Hydrogel optical waveguide spectroscopy (HOWS) provides a sensitive and effective platform for label-free hormone detection.
• The developed biosensor offers significant advantages over traditional SPR methods for E2 quantification.
• This technology holds promise for improved diagnostic, quality control, and environmental monitoring applications.