Specific staining of cancer cells is momentous for cancer research. Nanoprobe with multivalent recognition is emerging as powerful tools for bioimaging, but the nonspecific cell uptake and complex functional modification procedures are still obstacles for specific detection and convenient synthesis. Carbon dots (CDs) with an intrinsic targeting ability, excellent optical properties and biocompatibility acquired from an efficient one-step fabrication procedure were urgently desired in specific cancer cells visualization. Herein, inspired by the interrelationships between interface and biomolecular mechanisms, we suggested that it was possible to construct CDs with the desired characteristics for folate receptor (FR) positive-expressed cancer cell imaging via rich hydroxyl groups Tris-assisted one-step hydrothermal treatment of folate acid (FA) and -Arginine (L-Arg) precursors. The prepared small-sized F-CDs were equipped with abundant hydroxyl, pterin and negative charge surface, and possessed environmental friendliness, outstanding photostability and biocompatibility. Moreover, F-CDs had an intrinsic FR positive-expressed cancer cell targeting ability without any post-modification of the ligands. Rich hydroxyl groups play a vital role in endowing the optical properties and biological effects of F-CDs. F-CDs could be used as a promising candidate for FR-expressed cancer cell labeling and tracking. In addition, the caveolae-mediated endocytosis pathway of F-CDs was ascertained. More importantly, experimental results confirmed that the combination of physicochemical properties may provide an efficient strategy to overcome non-specific cell uptake interactions for cell labeling. Our strategy put forward a promising alternative to design fluorescent CDs for extensive chemical and biomedical applications.

中文翻译：

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Tris辅助一步法制备功能性碳点用于特定叶酸受体阳性表达的癌细胞成像

癌细胞的特异性染色对于癌症研究至关重要。具有多价识别功能的纳米探针正在成为生物成像的强大工具，但非特异性细胞摄取和复杂的功能修饰程序仍然是特异性检测和方便合成的障碍。在特定的癌细胞可视化中，迫切需要通过高效的一步制造程序获得具有内在靶向能力、优异的光学特性和生物相容性的碳点（CD）。在此，受界面和生物分子机制之间相互关系的启发，我们提出，通过富含羟基的Tris辅助一步水热处理，可以构建具有叶酸受体（FR）阳性表达癌细胞成像所需特征的CD。叶酸 (FA) 和 -精氨酸 (L-Arg) 前体。所制备的小尺寸F-CDs具有丰富的羟基、蝶呤和负电荷表面，具有环境友好性、优异的光稳定性和生物相容性。此外，F-CD 具有内在的 FR 阳性表达的癌细胞靶向能力，无需对配体进行任何后修饰。丰富的羟基在赋予F-CD的光学特性和生物效应方面发挥着至关重要的作用。 F-CD 可作为 FR 表达的癌细胞标记和追踪的有前景的候选者。此外，还确定了小窝介导的 F-CD 内吞途径。更重要的是，实验结果证实，物理化学特性的组合可以提供一种有效的策略来克服细胞标记的非特异性细胞摄取相互作用。我们的策略提出了一种有前途的替代方案来设计用于广泛化学和生物医学应用的荧光 CD。