A high-throughput photothermal aptasensing platform using MnO₂@CuS nanoprobes for noninvasive detection of bladder cancer cells in simulated liquid biopsy.

A high-throughput aptamer-based photothermal (PT) sensing platform has been developed using MnO₂@CuS nanoprobes for the noninvasive detection of exfoliated bladder cancer cells (HT-1376) in simulated liquid biopsy samples. A specific aptamer (Apt1) targeting epithelial cell adhesion molecule (EpCAM) was immobilized on an amino-functionalized glass slide to selectively capture target cells, and a thiolated aptamer-conjugated MnO₂@CuS nanoprobe (Apt2) was employed for photothermal signal output. Upon 808 nm laser irradiation, infrared thermographic imaging was used to monitor temperature elevation, enabling quantitative determination of cell concentration. The platform demonstrated a strong linear relationship between photothermal signal and HT-1376 concentration in the range 1.0 × 10 to 1.0 × 10⁶ cells/mL (R² = 0.993), with excellent sensitivity, selectivity, and repeatability. This is the first report of applying photothermal infrared imaging in a high-throughput format for tumor cell detection, offering a promising strategy for early and noninvasive diagnosis of bladder cancer via liquid biopsy.