A photoelectrochemical-fluorescence dual-mode microfluidic platform for subtype-analysis of hepatocellular carcinoma...

Circulating tumor cells (CTCs) are clinically important liquid biopsy biomarkers for cancer diagnosis, therapeutic monitoring, and prognosis. However, their extremely low abundance and pronounced phenotypic heterogeneity remain significant challenges for reliable detection and characterization. Herein, a dual-mode microfluidic platform integrated with photoelectrochemical (PEC) aptasensing and fluorescence imaging for the in-situ capture, identification, and phenotypic discrimination of CTCs directly from whole blood was developed. In this system, tumor cells were labeled with a near-infrared fluorescent probe (BDP-DNBS) and subsequently processed within a microfluidic chip for enrichment and on-chip analysis. A Bi₂S₃/Sb₂S₃/AuNPs nanocomposite was employed as the photoactive element to generate a sensitive PEC response, while subtype-specific aptamers were employed for the selective recognition of different hepatocellular carcinoma cell lines. This design allows simultaneous fluorescence visualization and PEC quantification within a single integrated platform. In spiked whole blood samples containing 200 cells mL^-1, the PEC measurements yielded 140 ± 6 cells mL^-1 for HepG2 and 146 ± 8 cells mL^-1 for Huh7. Correspondingly, fluorescence imaging provided values of 137 ± 4 and 144 ± 7 cells mL^-1, respectively. The strong agreement between the two detection modes demonstrates the robustness and analytical reliability of the proposed platform. Overall, this work presents a multimodal microfluidic sensing strategy for the analysis of heterogeneous liver cancer cells and offers a promising approach for blood-based CTC detection and phenotypic profiling in hepatocellular carcinoma.