Quantitative analysis of disaggregation properties of aggregation-induced emission luminogens (AIEgens) and off-the-shelf dyes

The aggregation state of chemosensors significantly influences their photophysical properties, making it critical for their applications in sensing and imaging. In this study, we systematically investigated the disaggregation properties of 11 representative fluorophores, including widely used dyes such as BODIPY, coumarin, fluorescein, rhodamine B, and Nile Red, as well as AIEgens like TPE and TPA. Through a quantitative approach, we determined the disaggregation concentration (DC₅₀) in various aqueous-organic co-solvent mixtures and correlated these values with solvent polarity parameters, such as dielectric constant and E_T(30). Our analysis uncovered distinct DC₅₀ patterns that act as unique fingerprints for each compound, reflecting their structural characteristics. Notably, structurally similar compounds, such as BODIPY derivatives and dansyl-based chemosensors, exhibited comparable trends. This study underscores the utility of solvent polarity versus DC₅₀ scatter plots for evaluating aggregation-dependent chemosensors and offers valuable insights into the molecular determinants of self-aggregation, enabling more rational chemosensor design.