Establishing a Fluorescence‐Size Correlation Methodology for Small‐Molecule Nanoassembly Evaluation

ABSTRACT Establishing the correlation between molecular aggregation state and nanoparticle size is essential for understanding the assembly behaviors, colloidal evolution, and in vivo fates of nanoassemblies (NAs). However, quantitative fluorescence‐size analysis of the dynamic assembly and colloidal stability of small‐molecule NAs remains underexplored. Here we employ self‐assembled NAs prepared from the aggregation‐induced emission (AIE)‐active molecule DPTH and its derivative DSH to relate AIE fluorescence variation to particle size evolution. Notably, DPTH and DSH exhibit distinct fluorescence variation during the NA process, suggesting the potential of AIE fluorescence change as another indicator beyond particle size. By leveraging this, an AIE fluorescence‐size dual‐index evaluation methodology is developed and validated for evaluating the assembly dynamics and colloidal stability of NAs. The established dual‐index evaluation methodology elucidates structure‐dependent NA behaviors overlooked by conventional size‐dominated characterization. Moreover, the in vitro stability ranking derived from the dual‐index evaluation showed a trend consistent with the pharmacokinetic performance of p‐DPTH NAs and p‐DSH NAs. This work advances quantitative size‐fluorescence analysis from static particle‐size correlation toward quantitative evaluation of dynamic NA stability.