Does fiber optic surface plasmon resonance possible in plastic core fibers ?

For Surface plasmon resonance we need and evanescent wave with decreasing intensity with penetration which only possible when we have TIR phenomena. In plastic core fiber due to less intense Evanescent wave not able to excite plasmon for resonance. it simply shows absorption and sensitivity decreases with respect of surrounding. so that's why Plastic core not showing any significant changes in peaks when surrounding changed.