A simplified high figure-of-merit prism-free surface plasmon resonance refractive index sensor based on self adaptive angular interrogation

We propose a simplified prism-free surface plasmon resonance (SPR) refractive index sensor based on self adaptive angular interrogation. An orthogonal V-shaped box with liquid sample is designed to achieve the functions of prism, sample cell, and mirror in a single setup. The rotator taking the self adaptive sample box is the sole mobile part in the system, which simplifies the structure greatly. A glass slide coated with Ag film is employed in this sample box as the sensing chip, in which the Ag film is isolated from the sample and air to prevent oxidation and pollution. According to the experimental results, the system can attain the figure-of-merit with 312.3/RIU, which is almost triple as high as that of the conventional prism-based sensor with the same samples. The proposed configuration could also be potentially utilized for the microminiaturization of the SPR sensor. (C) 2015 AIP Publishing LLC.