Surface Plasmon Resonance Sensor Based on Fe₂O₃/Au for Alcohol Concentration Detection

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Hematite (α-Fe2O3) possesses excellent optical properties, making it suitable for sensor sensitization.
• Surface Plasmon Resonance (SPR) sensors are valuable for detecting changes in refractive index.
• Combining hematite with gold nanostructures can potentially enhance SPR sensor performance.

Purpose of the Study:

• To develop and characterize a sensitivity-enhanced SPR alcohol sensor utilizing a Fe2O3/Au structure.
• To evaluate the impact of multiple Fe2O3 coatings on sensor sensitivity and performance.
• To demonstrate the practical application of the developed sensor in detecting alcohol concentrations in beverages.

Main Methods:

• Fabrication of the Fe2O3/Au sensor structure.
• Structural characterization of the sensor.
• Performance testing using solutions with a refractive index gradient (1.3335-1.3635).
• Comparison of sensitivity between Fe2O3/Au sensors and pure gold sensors.

Main Results:

• The Fe2O3/Au sensor coated twice achieved the highest sensitivity of 2933.2 nm/RIU within the tested refractive index range.
• This represents a 30.26% enhancement in sensitivity compared to a pure gold monolayer sensor.
• The sensor demonstrated accurate alcohol concentration detection in common beverages, aligning well with theoretical values.

Conclusions:

• The Fe2O3/Au nanostructure significantly enhances the sensitivity of SPR alcohol sensors.
• The developed sensor shows high potential for practical applications in food and beverage analysis.
• Optimizing the coating layers of hematite is crucial for maximizing sensor performance.