A one-pot sonochemical method was developed for the green synthesis of highly fluorescent carbon dots with nitrogen dopants (N@C-dots) derived from crab shells. The synthesized N@C-dots exhibited excellent water solubility with a fluorescence quantum yield of 14.5%. The N@C-dots then conjugated with folic acid (FA) to construct the N@C-dots-FA nanoprobe with the ability to selectively target folate-receptor positive cancer cells. Moreover, in vitro cytotoxicity studies showed excellent biocompatibility. Cellular uptake of the N@C-dots-FA was further studied via in vitro confocal microscopy studies. Results showed that N@C-dots-FA nanoprobes were mostly localized in the cytoplasm of the folate receptor-overexpressing Human cervical cancer cell (HeLa) while cellular uptake by human embryo lung cell (HEL) cells (folate receptor-deficient control) was negligible. Based on their improved diagnostic imaging and enhanced targeting effect, the N@C-dots-FA probe has high potential in the theranostic applications. This study demonstrates an economically viable approach to synthesize N@C-dots-FA probe using seafood waste.

开发了一种一锅式声化学方法，用于绿色合成高荧光碳点和源自蟹壳的氮掺杂剂（N @ C点）。合成的N @ C点表现出优异的水溶性，其荧光量子产率为14.5％。然后将Nc点与叶酸（FA）结合，以构建具有NcC点FA纳米探针的能力，该探针具有选择性靶向叶酸受体阳性癌细胞的能力。此外，体外细胞毒性研究显示出极好的生物相容性。通过体外进一步研究了N @ C-dots-FA的细胞摄取共聚焦显微镜研究。结果表明，N @ C-dots-FA纳米探针主要定位于过表达叶酸受体的人宫颈癌细胞（HeLa）的细胞质中，而人胚肺细胞（HEL）细胞的细胞摄取（叶酸受体缺乏的对照）微不足道。基于其改进的诊断成像和增强的靶向效果，N @ C-dots-FA探针在治疗学应用中具有很高的潜力。这项研究证明了使用海鲜废物合成N @ C-dots-FA探针的经济可行方法。