As a non-invasive, highly specific and sensitive assay strategy, liquid biopsy plays an important role in the diagnosis, the prognosis and the adjuvant therapy of cancer. Circulating tumor cell (CTC) have been considered as a crucial biomarker for liquid biopsy. However, CTCs are difficult to be detected accurately due to their very low content in blood. Herein, HepG2 cells stained with Hcy-716 fluorescence probe were separated and enriched from blood through inertial separation in a microfluidic chip, and then were detected by fluorescent and photoelectrochemical strategies simultaneously. Sulfhydryl functionalized TLS11a aptamers were fixed on a gold nanorods modified screen printing electrode surface to supply a photoelectrochemical cytosensing platform for HepG2 cells. Under optimized conditions, the separation efficiency and the purity of HepG2 cells can reach 82.6% and 73.4%, respectively. A linear response was obtained in the range of 1 × 10² ∼ 5 × 10⁵ cells mL⁻¹, and the detection limit was calculated to be 15 cells mL⁻¹. The separation with microfluid chip and detection with fluorescent imaging and photoelectrochemical aptasensing dual-model strategy provide a practical tool for CTCs assay, thus benefiting for liquid biopsy in cancer diagnosis.

液体活检作为一种无创、高特异性和灵敏的检测策略，在癌症的诊断、预后和辅助治疗中发挥着重要作用。循环肿瘤细胞 (CTC) 已被认为是液体活检的重要生物标志物。然而，由于 CTC 在血液中的含量非常低，因此难以准确检测。在此，Hcy-716 荧光探针染色的 HepG2 细胞在微流控芯片中通过惯性分离从血液中分离富集，然后通过荧光和光电化学策略同时检测。巯基功能化的 TLS11a 适体固定在金纳米棒上修饰丝网印刷电极表面，为 HepG2 细胞提供光电化学细胞传感平台。在优化条件下，HepG2细胞的分离效率和纯度分别达到82.6%和73.4%。^{在1×10 2} ∼ 5×10 ⁵ cells mL ^-1范围内获得线性响应，检测限计算为15 cells mL ^-1。微流控芯片分离、荧光成像检测和光电化学适体传感双模型策略为CTCs检测提供了实用工具，从而有利于液体活检在癌症诊断中的应用。