Ultrasensitive PEC cytosensor for breast cancer cells detection and inhibitor screening based on plum-branched CdS/BiS heterostructures.

Breast cancer is the most common malignant tumor in women, which seriously threatens the life and health of patients. Therefore, facile and sensitive detection of human breast cancer cells is crucial for cancer diagnosis. In this work, plum-branched CdS/BiS heterostructures (CdS/BiS HSs) were synthesized under hydrothermal condition, whose photoelectrochemical (PEC) property and biocompatibility were scrutinously investigated. In parallel, a signal amplification strategy was designed based on immune recognition between epidermal growth factor receptor (EGFR) overexpressed on membrane of breast cancer cells MDA-MB-231 and its aptamer. Integration of the above together, a highly sensitive PEC cytosensor was developed for analysis of target MDA-MB-231 cells, exhibiting a wider linear range of 1 × 10 ∼ 3 × 10 cells mL with a limit of detection (LOD) down to 6 cells mL (S/N = 3). Further, the biosensor was explored for anticancer drug (e.g., dacomitinib) screening by monitoring the variations in the PEC signals of the expressed EGFR upon drug stimulation. The obtained CdS/BiS HSs are identified as promising and feasible photoactive material for determination of cancer cells and drug screening in clinic and related research.