Carbon-based quantum dots (CDs) are mainly divided into two sub-groups; carbon quantum dots (CQDs) and graphene quantum dots (GQDs), which exhibit outstanding photoluminescence (PL) properties, low toxicity, superior biocompatibility and facile functionalization. Regarding these features, they have been promising candidates for biomedical science and engineering applications. In this work, we reviewed the efforts made to modify these zero-dimensional nano-materials to obtain the best properties for bio-imaging, drug and gene delivery, cancer therapy, and bio-sensor applications. Five main surface modification techniques with outstanding results are investigated, including doping, surface functionalization, polymer capping, nano-composite and core-shell structures, and the drawbacks and challenges in each of these methods are discussed.

碳基量子点（CD）主要分为两个子组。碳量子点（CQD）和石墨烯量子点（GQD），它们具有出色的光致发光（PL）特性，低毒性，优异的生物相容性和便捷的功能化。关于这些功能，它们已经成为生物医学和工程应用的有希望的候选者。在这项工作中，我们回顾了为修改这些零维纳米材料而获得的努力，以获取生物成像，药物和基因递送，癌症治疗以及生物传感器应用的最佳性能。研究了五种主要的表面改性技术，这些技术具有出色的结果，包括掺杂，表面功能化，聚合物封端，纳米复合材料和核-壳结构，并讨论了每种方法的缺点和挑战。