In this study, an ultrasensitive electrochemical biosensor fabricated from the deposition of nitrogen-doped graphene quantum dots (NGQDs) and phytohemagglutinin-L (PHA-L) onto screen-printed electrodes (SE) was successfully developed for breast cancer cell (MCF-7) detection in human serum. NGQDs with particle sizes of 3–12 nm were fabricated via a microwave-assisted hydrothermal method using passion fruit juice as the green carbon source, and then were conjugated with PHA-L through the amide bond between the COOH group of NGQDs and the NH₂ group of PHA-L. The dual-functionalized NGQDs can enhance the electrical conductivity of the electrochemical sensor and serve as the nanocargo for PHA-L, a highly specific receptor for effective anchoring of MCF-7, and subsequently result in the ultrasensitive and highly selective detection of MCF-7. The prepared SE= |NGQDs/PHA-L sensor exhibited a wide linear detection range from 5 to 10⁶ cells mL⁻¹ in phosphate-buffered saline (PBS) and 20–10⁶ cells mL⁻¹ in human serum with extremely low detection limits of 1 and 2 cells mL⁻¹, respectively. Moreover, the superior selectivity over 6 different interferents and long-term stability after 80 d of storage in human serum make the NGQDs/PHA-L complex an excellent sensing probe that can electrochemically detect low concentrations of cancer cells for the early diagnosis and treatment of breast cancer and other malignant neoplasms.

在这项研究中，成功​​开发了一种用于乳腺癌细胞（MCF-7）的超灵敏电化学生物传感器，该传感器由氮掺杂石墨烯量子点（NGQDs）和植物血凝素-L（PHA-L）沉积到丝网印刷电极（SE）上。 ) 在人血清中检测。以百香果汁为绿色碳源，通过微波辅助水热法制备粒径为 3-12 nm 的 NGQD，然后通过 NGQD 的 COOH 基团与 NH _{2之间的酰胺键与 PHA-L 共轭}PHA-L 组。双功能化的 NGQD 可以增强电化学传感器的电导率，并作为 PHA-L 的纳米载体，PHA-L 是一种用于有效锚定 MCF-7 的高度特异性受体，从而导致对 MCF-7 的超灵敏和高选择性检测. 制备的 SE= |NGQDs/PHA-L 传感器在磷酸盐缓冲盐水 (PBS) 中表现出从 5 到 10 ^{6 个}细胞 mL ^{-1的宽线性检测范围，在人血清中表现出从 20-10 6 个}细胞 mL ^-1的宽线性检测范围，检测率极低1 和 2 个细胞的限制 mL ^-1， 分别。此外，NGQDs/PHA-L复合物对6种不同干扰物的优异选择性和在人血清中储存80天后的长期稳定性，使NGQDs/PHA-L复合物成为一种极好的传感探针，可以电化学检测低浓度癌细胞，用于早期诊断和治疗癌症。乳腺癌和其他恶性肿瘤。