Near-Infrared Light-Driven Photoelectrochemical Aptasensor Based on the Upconversion Nanoparticles and TiO₂/CdTe Heterostructure for Detection of Cancer Cells

A near-infrared-driven photoelectrochemical aptasensor was developed as a new method for the detection of the breast cancer cell MCF-7. The upconversion nanoparticles and TiO 2 /CdTe heterostructure were combined to prepare the film electrode, and the high-affinity aptamer AS1411 was conjugated to the electrode to recognize MCF-7 cells. In this fabrication, the upconversion nanoparticles transferred the near-infrared light to visible light, which could excite the semiconductor to enhance the current response. As a result, the aptasensor revealed good sensitivity and specificity with MCF-7 cell concentrations ranging from 1 × 10 3 to 1 × 10 5 cells/mL. The results presented a favorable determination of MCF-7 cells, which was achieved with the help of the upconversion nanoparticles and the photoelectrochemical interface.