Fabrication and enhancement of sensor for measuring NaCl concentrations using surface plasmon resonance

초록

Surface plasmon polaritons can be excited by applied electromagnetic waves to have plasma oscillations. This phenomenon is named as Surface Plasmon Resonance(SPR) that was first observed in the 1900’s. Kretschmann suggested a practical application and commercial use of SPR. SPR sensor as his configuration is based on Attenuated Total Reflection(ATR) method and has a simple setup[1]. Light excite the SPR in the surface of metals and the resonance conditions are very sensitive to physical properties of the metal surface. Changes of the optical constants on the metal surface have a great influence on the resonance condition, which is the basis of SPR sensors for concentration-sensing purposes[2]. There are many cases that we urgently need to detect concentrations or variations of specific material in medical science, biology and so on. For example, irrigation water has requirement that the NaCl concentration is less than 500ppm. And compact, high-precision, and inexpensive sensors are required to accelerate research in this field. To realize these aims, a growing number of sensors based on SPR have been developed in recent years.