Cui Lin, Shen Jingzhu, Ai Shiyun, Wang Xiaolei, Zhang Chun-Yang
College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, 250014, China.
College of Chemistry and Material Science, Shandong Agricultural University, Taian, 271018, China.
Biosens Bioelectron. 2020 Nov 15;168:112545. doi: 10.1016/j.bios.2020.112545. Epub 2020 Aug 27.
Sensitive detection of cancer cells is essential to early clinic diagnosis, and the photoelectrochemical (PEC) sensors with high sensitivity and good selectivity may provide new approaches for cytosensing. Herein, we demonstrate the development of a new cathodic PEC cytosensor based on the integration of covalent organic polymer (COP) with palladium nanoparticles (PdNPs). The COP films are in-situ grown at room temperature on the transparent indium tin oxide-coated glass substrates, and they subsequently assemble with PdNPs to immobilize aptamers via palladium-sulfur chemistry. PdNPs can catalyze the oxidation of dopamine to produce aminochrome and its derivative, which may function as the electron acceptors of COP for the generation of an enhanced photocurrent. In the absence of cancer cells, the electrons on the conduction band of COP on the electrode transfer to the aminochrome and O, while the electrons on the electrode transfer to the hole of valence band, resulting in a high cathodic photocurrent. In the presence of cancer cells, the trapped cancer cells efficiently cover the electrode to reduce the surface of COP/PdNPs, resulting in the decrease of catalytic precipitation on the electrode and consequently the generation of a low PEC signal. This PEC cytosensor exhibits high sensitivity with a detection limit of 8 cells mL and a large dynamic range from 10 to 10 cells mL. Moreover, this PEC cytosensor has distinct advantages of high selectivity, good reproducibility and excellent stability, and it can be extended to directly detect various cancer cells through the integration with corresponding specific aptamers.
癌细胞的灵敏检测对于早期临床诊断至关重要，而具有高灵敏度和良好选择性的光电化学（PEC）传感器可为细胞传感提供新方法。在此，我们展示了一种基于共价有机聚合物（COP）与钯纳米颗粒（PdNPs）集成的新型阴极PEC细胞传感器的开发。COP薄膜在室温下原位生长在透明氧化铟锡涂层玻璃基板上，随后与PdNPs组装，通过钯 - 硫化学固定适配体。PdNPs可催化多巴胺氧化生成氨基铬及其衍生物，它们可作为COP的电子受体以产生增强的光电流。在不存在癌细胞的情况下，电极上COP导带的电子转移到氨基铬和O，而电极上的电子转移到价带的空穴，导致高阴极光电流。在存在癌细胞的情况下，捕获的癌细胞有效地覆盖电极，减少COP/PdNPs的表面，导致电极上催化沉淀减少，从而产生低PEC信号。这种PEC细胞传感器具有高灵敏度，检测限为8个细胞/毫升，动态范围从10到10个细胞/毫升。此外，这种PEC细胞传感器具有高选择性、良好的重现性和出色的稳定性等明显优势，并且通过与相应的特异性适配体集成可扩展到直接检测各种癌细胞。
