Functionalized black phosphorus (BP) nanosheets have been considered as promising nanoagents in cancer therapy due to their excellent photothermal conversion efficiency. However, it is still difficult to visually monitor the dynamic localization of BP nanoagents in cancer cells. In this paper, we systematically studied the second-harmonic generation (SHG) signals originating from exfoliated BP nanosheets. Interestingly, under the excitation of a high frequency pulsed laser at 950 nm, the SHG signals of BP nanosheets in vitro are almost undetectable because of their poor stability. However, the intracellular SHG signals from BP nanosheets could be measured by in vivo optical imaging due to the efficient enrichment of living HeLa cells. Moreover, the SHG signal intensity from BP nanosheets increases with the prolonged incubation time. It can be expected that the BP nanosheets could be a promising intracellular SHG nanoprobe employed for visually in vivo biomedical imaging in practical cancer photothermal therapy (PIT).

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黑磷纳米片中细胞内二次谐波成像的观察

功能化的黑磷（BP）纳米片因其优异的光热转换效率而被认为是癌症治疗中很有前途的纳米剂。然而，仍然难以直观地监测 BP 纳米剂在癌细胞中的动态定位。在本文中，我们系统地研究了源自剥离的 BP 纳米片的二次谐波产生 (SHG) 信号。有趣的是，在 950 nm 的高频脉冲激光的激发下，BP 纳米片的 SHG 信号体外由于稳定性差，几乎无法检测到。然而，来自 BP 纳米片的细胞内 SHG 信号可以通过体内光学的由于活 HeLa 细胞的有效富集而成像。此外，来自 BP 纳米片的 SHG 信号强度随着孵育时间的延长而增加。可以预期，BP纳米片可能是一种有前途的细胞内SHG纳米探针，用于视觉体内实际癌症光热治疗（PIT）中的生物医学成像。