Photodynamic therapy (PDT) holds great promise as an effective approach to kill multidrug resistant (MDR) bacteria. In this study, KMnF3:Yb,Er upconversion nanoparticles (UCNPs) were prepared and modified with zinc phthalocyanine (ZnPc), a photosensitizer with a major absorption band at 670[Formula: see text]nm. ZnPc absorbs the emission at 660[Formula: see text]nm of the UCNPs producing reactive oxygen species (ROS) which kill the surrounding bacteria. The UCNPs were also modified with Tween to make them water-soluble and biocompatible, and oleylamine to provide positive charges to shorten the distance from bacteria. Detection of singlet oxygen production, bacteria viability test and confocal imaging were performed, respectively. The as-prepared system (UCNPs@ZnPc@Tween) shows enhanced efficiency of PDT against both Gram-negative and Gram-positive bacteria.

中文翻译：

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用于抗菌应用的 ZnPc/KMnF3: Yb、Er 上转换光动力治疗系统的一步自组装

光动力疗法 (PDT) 作为杀死多重耐药 (MDR) 细菌的有效方法具有很大的前景。在这项研究中，制备了 KMnF3:Yb,Er 上转换纳米粒子 (UCNPs)，并用酞菁锌 (ZnPc) 进行了改性，这是一种在 670[公式：见正文]nm 处具有主要吸收带的光敏剂。ZnPc 吸收 UCNPs 在 660[公式：见正文]nm 处的发射，产生活性氧 (ROS)，杀死周围的细菌。UCNPs 还用 Tween 进行了修饰，使其具有水溶性和生物相容性，并使用油胺提供正电荷以缩短与细菌的距离。分别进行单线态氧产生检测、细菌活力测试和共聚焦成像。