Surface plasmon resonance device with imaging processing detector for refractive index measurements

This work presents a new surface plasmon resonance (SPR) instrument based on Kretschmann configuration. This device acquires and processes the reflected SPR image of the sample by using a webcam together with an image processing algorithm that transforms the RGB image in numeric values and correlates the integrated intensity with the refractive index of the solution. Experimental signals were compared with theoretical values and it was found an excellent agreement. In addition, the applicability of the instrument was tested by measuring the refractive index of solutions in a continuous flow mode. Excellent stability and sensitivity of the signal were found in the presence of small changes of the refractive index.