fluorescence sensing based on carbon dot-metallic deep eutectic solvent and perylene bisimide nanocubes

As an answer to the scientific challenges of the 21st century, our modern world today is increasingly shaped by optical sensors. remarkable photo-stability, high-flexible surface modification, good water solubility, low cost and toxicity, and excellent biocompatibility are the key issues in developing optical sensors. research and development of innovative concepts for high-performance sensors are in our research group, providing solutions for a widespread range of applications, such as food quality control [1], cancer detection [2,3] and drug monitoring.in this contribution, the preparation of a miniaturized fluorescent probe based on the ultrasound‒assisted formation of carbon dots (cds) in a metallic deep eutectic solvent (mdes) is discussed. in-situ synthesis of cds-chelated metals in the presence of the target analyte facilitates a kinetically fluorescence emission with no need to multi-step analysis. simultaneous implementation of mdes as a green solvent and passivation agent also practically paves the way to minimize the hazardous chemicals consumption. chelation of the divalent metal cations on the synthesized cds and their strong interactions with the imidazole ring presumably provides a fluorescence quenching pathway induced by 4-methylimidazol (4-mei) in commercial dark soft drinks. also, the synthesis and characterization of a nanocubic morphology of perylene bisimide (pbi) derivative in which imide nitrogen atoms substituted by bulky polyhedral oligomeric silsesquioxane (poss) to prevent π stacking is disclosed. the synthesized compound shows an intense red emission in solid state with an appropriate quantum yield efficiency. this nanocubic material is suitable for highly selective and highly sensitive (ng l-1 level) detection of gaseous aniline derivatives which are particularly vital in lung cancer detection. our investigation showed that revealed sensor is more suitable than previously reported β-cyclodextrin grafted or bay area twisted pbi systems for photoinduced electron transfer reaction which has considered as a main pathway for quenching of pbi species in many applications including aniline derivatives sensing.