KAJIAN FENOMENA SURFACE PLASMON RESONANCE (SPR) PADA SISTEM LOGAM/POLIMER KONDUKTIF SEBAGAI SENSOR GAS; THE STUDY ON SURFACE PLASMON RESONANCE (SPR) PHENOMENON IN METAL/CONDUCTIVE POLYMER SYSTEM AS GAS SENSOR

Muhammad Arifin, Kamsul Abraha

2011 | Disertasi | PROGRAM STUDI S2 ILMU FISIKA

Have been observed the phenomenon of surface plasmon resonance (SPR) on a thin layer of conductive polymer, poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT: PSS) is as an ammonia gas sensor. Surface plasmon is electromagnetic wave that spreads in metal-dielectric interface that can be excited by the method of attenuated total reflection (ATR) in the Kretschmann configuration. Resonance condition, called SPR angle, occurs when the constant wave surface plasmon coupled with a constant evanescent wave HeNe laser beam (? = 632.8 nm). SPR curves are obtained by observing the reflectance of laser incident angle variation on the prism. SPR angle for the prism/Ag system is 43,900 ± 0,050 with a constant wave surface plasmon (SP) being 1,04 × 107 m-1. Due to the addition of a PEDOT:PSS thin film, SPR angle shifed into 45,100 ± 0,050 and a constant wave SP is 1,06 × 107 m-1. After reacted with ammonia gas, the SPR angle shifts to 47,900 ± 0,05 with changing the constant of wave to be 1,11 × 107 m-1. The shifting of SPR angle shows that sensitivity SPR is as gas sensor.

Kata Kunci : surface plasmon resonance (SPR), sensor gas, PEDOT:PSS, gas amoniak