(a) Schematic of simple synthesis of dye-loaded PNCs. PNC was synthesized using a supramolecular template (PBDT-TA). By virtue of glue-like nature of PDA, PNC was loaded with small molecular dyes (e.g., NB, AA, and MB) via multiple interactions. (b) During heparin interactions, negatively charged PNCs released the loaded dyes in PNCs, while positively charged PNCs showed particle aggregation that increased PA signal.