Normally, electrostatic-dependent mitochondria localization can cause a decrease/loss of mitochondrial membrane potential (MMP), leading to the corresponding abnormal behaviors. So, achieving subcellular organelle localization and imaging with as little interference on their physiological activity is of significance for understanding cell activity. Herein, we discover and demonstrate that “polarity” can independently act as a novel kind of target for labeling at the organelle level. On this basis, mitochondria and lysosomes are precisely fluorescently imaged by two kinds of polarity-targeted carbon dots (C-dots), respectively. The two C-dots, named C-dots-1 and C-dots-2, have almost identical size and morphology as well as surface chemistry. The subtle difference is their polarity property: both of them are amphiphilic, with 1.54 and 0.95 for the log P values. Different from commonly used cationic-based organelle probes, both of the two C-dots possess slightly negatively charged surfaces (ζ-potential values ∼ −2.5 to −7.5 mV) at physiological conditions. Interestingly, the C-dots-1 and C-dots-2 have the capacity for highly selectively labeling and imaging mitochondria and lysosomes, whether cancer cells or normal cells. Because the targeting processes do not rely on electrostatic attraction effects, the MMP is not changed during localization processes. So, the corresponding cell abnormal behaviors caused by MMP diminishing, for example, the autophagy phenomenon, can be effectively avoided.

中文翻译：

---

用于线粒体和溶酶体成像的极性靶向碳点


正常情况下，静电依赖性线粒体定位会导致线粒体膜电位 （MMP） 降低/丢失，从而导致相应的异常行为。因此，在对其生理活性干扰尽可能小的情况下实现亚细胞器定位和成像对于了解细胞活动具有重要意义。在此，我们发现并证明了“极性”可以独立地作为细胞器水平标记的新型靶标。在此基础上，线粒体和溶酶体分别由两种极性靶向碳点 （C 点） 精确荧光成像。这两个 C 点，命名为 C-dots-1 和 C-dots-2，具有几乎相同的大小和形态以及表面化学性质。细微的区别在于它们的极性特性：它们都是两亲性的，log P 值为 1.54 和 0.95。与常用的阳离子细胞器探针不同，在生理条件下，这两个 C 点都具有带轻微负电荷的表面（ζ电位值 ∼ -2.5 至 -7.5 mV）。有趣的是，C 点-1 和 C-点-2 具有高度选择性标记和成像线粒体和溶酶体的能力，无论是癌细胞还是正常细胞。由于靶向过程不依赖于静电吸引效应，因此在定位过程中 MMP 不会改变。因此，可以有效避免 MMP 减少引起的相应细胞异常行为，例如自噬现象。