Biomimetic synthesis is a promising strategy for the preparation of nanotheranostics with excellent biocompatibility. Herein, we report a biomimetic approach to synthesize folic acid (FA) modified copper sulfide (CuS) nanodots for cancer phototheranostics by using melanin as a biotemplate and FA as a stabilizer. Owing to the high affinity of melanin for metal ions, copper ions can be adsorbed on the surface of melanin and then reacted with S²⁻ ions to form CuS nanodots. As a natural biomolecule, melanin has high biocompatibility and biodegradability, which can effectively improve the biosafety of the prepared CuS nanodots. More importantly, both melanin and CuS have strong near-infrared (NIR) absorption, the as-prepared CuS-Melanin-FA composite nanoprobes with high photothermal conversion efficiency are promising for augmented photoacoustic imaging and photothermal therapy of cancer, which is demonstrated on 4T1 tumor-bearing mice. Moreover, the biomimetic synthesis method for the preparation of CuS nanodots opens a new horizon for the biomimetic synthesis of other nanotheranostics.

仿生合成是制备具有优异生物相容性的纳米热杂物的一种有前途的策略。在这里，我们报道了一种仿生方法，通过使用黑色素作为生物模板和FA作为稳定剂来合成叶酸（FA）修饰的硫化铜（CuS）纳米点，用于癌症光疗。由于黑色素对金属离子的高亲和力，铜离子可被吸附在黑色素的表面，然后与S ^2-离子形成CuS纳米点。黑色素作为天然生物分子，具有很高的生物相容性和生物降解性，可以有效提高制备的CuS纳米点的生物安全性。更重要的是，黑色素和CuS都具有很强的近红外（NIR）吸收能力，制备的具有高光热转换效率的CuS-黑色素-FA复合纳米探针有望用于增强的光声成像和癌症光热疗法，这在4T1上得到了证明。荷瘤小鼠。而且，用于制备CuS纳米点的仿生合成方法为其他纳米热力学的仿生合成开辟了新的视野。