Dual-parameter measurement of refractive index and temperature using an L-shaped POF-SPR sensor

Abstract This study presents an L-shaped plastic optical fiber-based surface plasmon resonance sensor fabricated using thermal imprinting. One arm of the L-shaped structure is coated with an Ag film, serving as the refractive index (RI) sensing channel, while the other arm is coated with an Ag/PDMS (polydimethylsiloxane) film, functioning as the temperature sensing channel, enabling dual-parameter detection of both RI and temperature. Experimental results demonstrate RI and temperature sensitivities of 1790.957 nm/RIU and −0.935 nm °C within the RI range of 1.333–1.363 and the temperature range of 0 °C–70 °C, respectively. These results significantly outperform most comparable studies. The sensor offers advantages including low cost, simple fabrication, high detection sensitivity, low crosstalk, and a wide temperature detection range, making it suitable for broad applications in biological and pharmaceutical domains.