Compact 5-LEDs illumination system for multi-spectral surface plasmon resonance sensing

Abstract

In this contribution, we quantify the performances of a low-cost, compact, multi-spectral illumination system allowing spectral interrogation to be performed in surface plasmon resonance imaging (SPRI) systems. Previous work demonstrated the feasibility of spectral interrogation based on a discrete number of scanning wavelengths using a white source and monochromator. Here, we expand this concept by building a multi-spectral SPRI system with five light-emitting diodes (LEDs). The development focuses on the improvement of the illumination stability, which is a critical parameter for the precision of the spectral interrogation measurement. The obtained prototype exhibits sensitivity and resolution properties comparable with reflectivity-interrogation-based SPRI systems, with the advantages of spectral interrogation, i.e. increased dynamical range and robustness towards solution index variations. These performances, as well as the real-time and 2-dimensional imaging modalities of the five-LEDs setup, are illustrated by a standard experiment of DNA–DNA interaction monitoring on a biochip format.