循环肿瘤细胞（CTCs）通常被认为是肿瘤转移的主要原因，最终可能导致死亡。因此，开发高性能的CTCs测定方法对于提高癌症生存率非常重要。光电化学生物传感系统已经被广泛研究和应用于生物测定。在此，通过简单的一步水热法成功制备了Bi2O2S纳米花。在与直径约为45nm的金纳米颗粒集成后，AuNPs/Bi2O2S纳米复合材料涂覆在ITO电极表面上，构建了一个可被近红外光激发产生光电流响应的光电化学传感平台。随后，在AuNPs/Bi2O2S/ITO表面上固定了巯基功能化的aptamer（SH-Apt）。由于细胞膜中MUC1蛋白的过度表达，MCF-7细胞被特异性地困住在SH-Apt/AuNPs/Bi2O2S/ITO表面上。引入MCF-7细胞会导致光电流响应明显降低。光电流变化与MCF-7细胞浓度的对数呈良好的线性关系，范围为50到6×105 cell mL-1。检测限为17 cell/mL。PEC生物传感器对于检测MCF-7细胞具有良好的灵敏度、选择性和稳定性，甚至可以在临床血清样本中检测MCF-7细胞。 版权所有 © 2023 Elsevier B.V.

Circulating tumor cells (CTCs) are commonly considered as the major cause of tumor metastasis and can eventually lead to death. Therefore, developing a high-performance method for the determination of CTCs is very significant for promoting the cancer survival rate. Photoelectrochemical biosensing systems have been extensively investigated and applied for bioassays. Herein, Bi2O2S nanoflowers were successfully prepared through a simple one-step hydrothermal method. After being integrated with gold nanoparticles with a diameter of ∼45 nm, AuNPs/Bi2O2S nanocomposites were coated onto an ITO electrode surface to build a photoelectrochemical sensing platform which can be excited with near-infrared light to produce photocurrent response. Subsequently, mercapto-group functionalized aptamer (SH-Apt) was fixed onto the AuNPs/Bi2O2S/ITO surface. Due to the overexpress of MUC1 protein in the cell membrane, MCF-7 cells were specifically trapped on the SH-Apt/AuNPs/Bi2O2S/ITO surface. The introduce of MCF-7 cells lead to an obvious decrease on the photocurrent response. The photocurrent variation shows a satisfied linear relationship to the logarithm of MCF-7 cells concentration ranged from 50 to 6 × 105 cell mL-1. The detection limit obtained is 17 cell mL-1. The PEC biosensor shows excellent sensitivity, selectivity and stability for sensing MCF-7 cells, even for determining MCF-7 cells in clinical serum samples.Copyright © 2023 Elsevier B.V. All rights reserved.