Optical Laser Tweezer-Directed Single Particle Solvatochromism of Conjugated Polydiacetylene

Solvatochromism plays a pivotal role in various scientific and technological fields including those that explore molecular interactions, sensing technologies, and organic electronics. Notably, despite their ease of manipulation, direct visualization, and potential for single particle-based sensing, micro-sized solid particles have been the focus of a surprisingly low number of solvatochromism investigations. In this study, polydiacetylene (PDA) particles are synthesized and their solvatochromism is investigated at the single particle level using optical laser tweezers-based methods. The findings reveal that unpolymerized monomers within PDA particles at the water/n-decane interface undergo dissolution in the n-decane phase to form internal voids in the particles. This phenomenon leads to structural deformation of the PDA which triggers a solvatochromic response. Studies that integrate this phenomenon with established particle-based methodologies should provide deeper insights into diverse chromism behaviors and potential applications of solvatochromic materials.