Novel photoelectrochemical immunosensor for MCF-7 cell detection based on n-p organic semiconductor heterojunction

In this work, we developed a novel photoelectrochemical (PEC) sensor based on n-p organic semiconductor heterojunction for sensitive detecting MCF-7 cancer cells. BTA-C4Ph and PM6 were designed as photoactive materials to form n-p heterojunction, which greatly enhanced the photoelectric conversion efficiency. Antibody-modified magnetic nanoparticles were utilized to capture and separate MCF-7 cells from samples. Detection of MCF-7 is ascribed to the loading of MCF-7 onto BTA-C4Ph-PM6 modified electrode that resulted in the decrease of photocurrent intensity. The PEC immunosensor displayed a linear concentration ranging from 50 cell/mL to 1 × 104 cell/mL with a limit of detection (LOD) of 41 cell/mL (S/N = 3) for MCF-7. Additionally, the senor also exhibited good stability, excellent selectivity and prominent reproducibility. Furthermore, the sensor was successfully applied to detect MCF-7 in whole blood. This work illustrates that n-p heterojunction of organic semiconductor may find wide applications for the preparation of different photoelectrochemical sensors.