A versatile and compact surface plasmon resonance spectrometer based on single board computer

The widespread diffusion of low-cost but high-performance hardware is enhancing the realization of scientific equipment with features at the research laboratory level. In this paper, we demonstrate hardware implementation of a surface plasmon resonance compact device with high accuracy and measurement times appropriate for many applications. Image acquisition is realized by a Raspberry Pi single board computer with a camera module, and a Python code is used to process data. A flexible optical setup can work in two different configurations, namely, the inspection mode and angle resolved measurement mode. The inspection mode is used to precisely locate the light-emitting diode interrogation beam on the sample, avoiding uneven or faulty regions. The measurement mode allows us to monitor in real time the position of the minimum reflectivity with subpixel resolution. Performance tests show a resolution in the bulk refractive index of 4.9 × 10^-6 refractive index units for 10 s acquisition time.