MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, P. R. China.
Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
Nanoscale. 2023 Oct 26;15(41):16727-16733. doi: 10.1039/d3nr04055k.
Nanoprobes based on lanthanide-doped upconversion nanoparticles (UCNPs) exhibit promising potential in bioimaging and biosensing due to their unique optical properties. However, conventional UCNP nanoprobes based on the dye quenching effect are still limited in biosensing due to their low upconversion efficiency. The advent of dye-sensitized upconversion has resulted in nanoprobes with significantly enhanced efficiency; however, these still suffer from a high initial emissive background. In view of this, herein, we have constructed a dye-quenched/sensitized switching upconversion nanoprobe for high-contrast imaging of the pH-related tumor microenvironment. Under normal conditions, the luminescence of the nanoprobe at 540 nm (UCL) was significantly quenched by the employed dye. Upon being triggered by an acid, the dye would switch to its fluorescent form to sensitize the luminescence of UCNPs, affording a significant enhancement of UCL. The switching from dye-quenched UCL to dye-sensitized UCL jointly enables the detection of a high signal-to-background ratio (high up to 50), allowing for high-contrast mapping of the tumor specific acidic microenvironment . We believe that this nanoplatform holds considerable promise for acid-related sensing.
基于镧系掺杂上转换纳米粒子（UCNPs）的纳米探针由于其独特的光学性质，在生物成像和生物传感中显示出有前途的潜力。然而，由于上转换效率低，基于染料猝灭效应的传统 UCNP 纳米探针在生物传感中仍然受到限制。染料敏化上转换的出现导致了效率显著提高的纳米探针；然而，这些探针仍然存在初始发射背景高的问题。有鉴于此，在这里，我们构建了一种用于 pH 相关肿瘤微环境高对比度成像的染料猝灭/敏化开关上转换纳米探针。在正常条件下，纳米探针在 540nm 处的发光（UCL）被所用染料显著猝灭。被酸触发后，染料会切换到荧光形式，敏化 UCNPs 的发光，从而显著增强 UCL。从染料猝灭 UCL 到染料敏化 UCL 的转换共同实现了高信噪比（高达 50）的检测，允许对肿瘤特异性酸性微环境进行高对比度映射。我们相信这个纳米平台在酸相关传感方面具有很大的潜力。
