Photoelectrochemical detection of circulation tumor cell based on metal-organic framework with incorporated copper peroxide nanodots as probe

Abstract

Signal nanoprobe based on copper peroxide nanodots (CPNs) embedded within metal–organic frameworks (ZIF-8) was applied for developing photoelectrochemical (PEC) sensor for detection of circulation tumor cells (CTC). The nanoprobe can self-supply H2O2 by encapsulated CPNs under acidic condition. The produced H2O2 can help generate insoluble precipitation onto sensor surface in the presence of horseradish peroxidase (HRP), leading to suppressed PEC current intensity. MCF-7 was selected as model CTC, which was enriched and separated from samples by antibody modified magnetic beads (MB). Organic semiconductor BTA-C4Ph and PM6 were chosen to form n-p heterojunction on sensor surface with enhanced PEC current intensity. The PEC sensor was constructed based on “sandwich” protocol, which has a linear range from 5 cell/mL to 100 cell/mL and a limit of detection (LOD) of 3 cell/mL (S/N = 3) for MCF-7. What more, the sensor was successfully applied for detection of MCF-7 in whole blood samples.