“…Depending on the application, different optical properties have been evaluated, such as transmittance [16,22,32], reflectance [47][48][49], fluorescence [33,43,45,46,18] and polarization [34,44]. The way that the light source is operated becomes defined by each particular problem, for instance, kinetic measurements of transmittance can be done at an optimized illuminating color that reflects the largest changes in transmittance upon reaction with target analytes [32,41,42].…”