Application of single metal Au and Ag/Si3N4/Au plasmonic sensors for glucose refractive index measurements

TL;DR

This study demonstrates the use of single gold and multilayer Ag/Si3N4/Au plasmonic sensors to detect glucose concentration changes via refractive index measurements, showing enhanced electric field strength in multilayer sensors.

Contribution

It introduces multilayer Ag/Si3N4/Au sensors for improved sensitivity in glucose refractive index detection and compares their performance with single gold sensors.

Findings

Multilayer Ag/Si3N4/Au sensors have stronger electric fields than single gold sensors.

Sensors can detect glucose concentrations as low as 1%.

Finite difference simulations confirm enhanced field strength in multilayer sensors.

Abstract

We have employed single gold layer metal and multilayer Ag/Si3N4/Au plasmonic sensors to monitor changes in the refraction index of glucose/water solutions. Our results show that the sensor can resolve glucose refractive index down to 1% concentration. In addition, we have simulated the strength of the surface plasmon resonance evanescent electric fields by using the finite difference method of COMSOL. The electric field strength for the Ag/Si3N4/Au sensor is much stronger than that for single gold layer SPR sensor.