Optical silicones are suitable materials for different additive manufacturing techniques. Premixing uncured silicones with nanoparticles enables the manufacturing of functional materials useable as emitting or even deformation sensing materials. The incorporation of particles in different media is mainly controlled by their surface which can be modified by surface active agents. This modification is the main part of this work, while flexible waveguides are printed to prove the concept. As functional species luminescent quantum dots have gained significant attention due to their optical properties and precise control over shape and size. In this work cadmium selenide-cadmium sulfide core–shell quantum dots are used due to their strong emission and high photoluminescence quantum yield (PLQY). While these properties are well known and tunable, matrix stability and the associated hazard potential are still relatively unknown. This is determined by immersion tests on differently modified samples. Inductively coupled plasma optical emission spectrometry is used to quantify the leaked amount of cadmium. The poster for this publication is available here: https://doi.org/10.15488/16039 .