Design and Simulation of Au/SiO₂ Nanospheres Based on SPR Refractive Index Sensor

Area of Science:

• Nanomaterials Science
• Optical Sensors
• Surface Chemistry

Background:

• Surface Plasmon Resonance (SPR) sensors are crucial for label-free biosensing.
• Conventional SPR sensors often use gold (Au) films.
• Enhancing SPR sensor sensitivity is an ongoing research objective.

Purpose of the Study:

• To investigate the impact of silicon dioxide (SiO2) morphology on SPR sensor performance.
• To compare the sensitivity of SPR sensors with different SiO2 structures (thin film, nanospheres, nanorods).
• To explore the relationship between material shape and sensor performance.

Main Methods:

• Designing three SPR sensor structures based on the Kretschmann configuration: Au/SiO2 thin film, Au/SiO2 nanospheres, and Au/SiO2 nanorods.
• Utilizing modeling and simulation techniques.
• Investigating sensor performance across a refractive index range of 1.330 to 1.365.

Main Results:

• The Au/SiO2 nanospheres structure achieved a sensitivity of 2875.4 nm/RIU.
• This sensitivity is 25.96% higher compared to a sensor with a gold array.
• The enhanced sensitivity is directly linked to the change in SiO2 material morphology.

Conclusions:

• The shape of the sensor-sensitizing material significantly influences SPR sensor performance.
• SiO2 nanospheres offer a promising approach for developing highly sensitive SPR sensors.
• Morphological optimization of nanomaterials is key to advancing SPR sensor technology.