Magnetic nanoparticles amplification-based terahertz and fluorescence dual-mode assays for efficient isolation and sensitive detection of circulating tumor cells.

Sensitive, specific and accurate detection of circulating tumor cells (CTCs) is critical for early cancer diagnosis and prognosis evaluation. Here, we developed an innovative dual-mode sensing platform that integrates terahertz (THz) and fluorescence (FL) technologies for the accurate quantification of CTCs. This platform employed a strategy based on magnetic nanoparticles (MNPs) isolation and amplification, wherein the assembly of MNPs on CTCs enhances their magnetic separation efficiency and both the THz and FL signals. This dual-mode method demonstrated excellent sensitivity for CTCs, with the limited of detection (LOD) 2 and 7 cells/mL for the THz and FL modes, respectively. On the basis of the complementary strengths of THz-FL detection, the platform also demonstrated excellent performance for practical applications in 30 cases of breast cancer patients. In THz mode, it achieved a sensitivity of 100 % and a specificity of 86.7 %, with an area under curve (AUC) of 0.973. In FL mode, it maintained a sensitivity and specificity of 90 % each, with an AUC of 0.820. Therefore, the integrated dual-mode platform shows significant potential for clinical applications and provides a promising tool for early cancer diagnosis in liquid biopsy.