Interactions between polyacrylic acid (PAA) arms of star block copolymers through metal ions were investigated by fluorescence resonance energy transfer (FRET). Dendritic polyester (DPE) core was grafted with block copolymer arms of oligo (ethylene glycol) methyl ether acrylate (OEGA) and PAA. Fluorescein o-methacrylate (FMA) or methacryloxyethyl thiocarbamoyl rhodamine B (MTR) was introduced via copolymerization to the terminated PAA blocks. The unique copolymer structure enabled FRET between PAA chains without causing precipitation, which inevitably occurs for linear PAA. Addition of metal ions such as Zn²⁺, Ca²⁺, or Na⁺ induced FRET, the order of which was Zn²⁺>Ca²⁺≫Na⁺. FRET intensity was also correlated with concentration of each ion. Furthermore, in situ FRET measurement during the hydrogel formation of the star block copolymers was performed by mixing the star block copolymers and Zn²⁺.

通过荧光共振能量转移（FRET）研究了星型嵌段共聚物的聚丙烯酸（PAA）臂之间通过金属离子的相互作用。树状聚酯（DPE）芯接枝有低聚（乙二醇）甲基醚丙烯酸酯（OEGA）和PAA的嵌段共聚物臂。通过共聚将荧光素邻甲基丙烯酸酯（FMA）或甲基丙烯酰氧基乙基硫代氨基甲酰基罗丹明B（MTR）引入封端的PAA嵌段中。独特的共聚物结构使PAA链之间的FRET不会引起沉淀，而线性PAA不可避免地会发生沉淀。添加诸如Zn 2 ⁺，Ca ²⁺或Na ⁺的金属离子诱导的FRET，其顺序为Zn ²⁺ > Ca ²⁺ ≫Na⁺。FRET强度也与每个离子的浓度相关。此外，通过将星型嵌段共聚物和Zn ²⁺混合来进行星型嵌段共聚物的水凝胶形成过程中的原位FRET测量。