Near-infrared (NIR) light-triggered pH-manipulation has been realized by utilizing upconversion nanoparticle assisted ring-closing reactions of the conventional photoacid merocyanine (MC). This pH manipulation behavior was then used to regulate the switch of an acid-labile cap for facilitating drug release on the basis of mesoporous silica coated upconversion nanoparticles, in which the drug release rate and amount and the cell killing ability have been greatly improved upon NIR light irradiation due to the locally high concentration of H⁺ within pore channels that is generated by upconversion assisted MC. This proof of concept may provide a way to utilize NIR light to regulate pH change for new drug delivery system designs and applications in biomedical field.

通过利用常规光酸部花菁（MC）的上转换纳米粒子辅助的闭环反应，实现了近红外（NIR）光触发的pH操纵。然后在介孔二氧化硅包被的上转换纳米粒子的基础上，使用此pH操纵行为来调节酸不稳定的帽的开关，以促进药物释放，其中通过近红外光谱大大改善了药物释放速率和数量以及细胞杀伤能力由于上转换辅助MC产生的孔道内H ⁺局部较高浓度，导致光照射。这一概念证明可以提供一种利用NIR光调节pH值变化的方法，以用于生物医学领域的新药物输送系统设计和应用。