Novel phospholipid/polydiacetylene vesicles are reported herein, and their optimized sensing performance and the effects of lactate counterions and pH are elucidated. Vesicles comprising 10,12-pentacosadyinoic acid (PCDA), PCDA/cholesterol/sphingomyelin (PCDA/CHO/SPH), PCDA/1,2-dimyristoyl-sn-glycero-3-phosphocholine (PCDA/DMPC), and PCDA/1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (PCDA/DMPG) were synthesized, and their diameters and colorimetric responses induced by sodium and calcium lactates were assessed. The vesicles were characterized at as-synthesized pH as well as at reduced (pH < pK_a) and increased (pH > pK_a) proton activities. This contribution demonstrates that the presence of lactate caused the colorimetric transition in PDA vesicles and that the interaction between these components depended upon vesicle composition, medium pH, and lactate counterion. Variations in vesicle diameter arising from calcium or sodium lactate concentrations are probably related to the disruption of vesicle surfaces, which does not change the internal molecular packing. Therefore, vesicle growth was not always responsible for the colorimetric transitions, which in fact were assigned to conformational changes of the PDA molecules.

中文翻译：

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用于乳酸传感的功能化聚二乙炔囊泡：相互作用研究

本文报道了新型磷脂/聚二乙炔囊泡，并阐明了它们优化的传感性能以及乳酸反离子和 pH 值的影响。囊泡包含 10,12-五十二碳二烯酸 (PCDA)、PCDA/胆固醇/鞘磷脂 (PCDA/CHO/SPH)、PCDA/1,2-二肉豆蔻酰基-sn-甘油-3-磷酸胆碱 (PCDA/DMPC) 和 PCDA/1合成了,2-dimyristoyl- sn -glycero-3-phosphoglycerol (PCDA/DMPG)，并评估了它们的直径和由乳酸钠和乳酸钙诱导的比色反应。囊泡在合成时的 pH 值以及降低 (pH < p K _a ) 和升高 (pH > p K _a ) 下表征) 质子活动。这一贡献表明，乳酸的存在导致了 PDA 囊泡中的比色转变，并且这些成分之间的相互作用取决于囊泡组成、介质 pH 值和乳酸平衡离子。由钙或乳酸钠浓度引起的囊泡直径的变化可能与囊泡表面的破坏有关，这不会改变内部分子堆积。因此，囊泡生长并不总是导致比色转变，这实际上是由于 PDA 分子的构象变化。