Sensitive cancer cell detection based on Au nanoparticles enhanced electrochemiluminescence of CdS nanocrystal film supplemented by magnetic separation

We report here a sensitive electrochemiluminescence (ECL) approach for detection of HL-60 cancer cells based on Au nanoparticles (NPs) enhanced ECL of CdS nanocrystal (NC) film supplemented by magnetic separation. In this approach, capture DNA-1 modified CdS NC film was used as ECL emitter. Capture DNA-2, which is labeled with Au NP, is hybridized with the aptamer modified on magnetic beads (MBs) to form MB-Au NP bioconjugates. In the presence of HL-60 cells, the aptamer would conjugate with the glycoprotein at cell surface and Au NPs labeled capture DNA-2 would be released. After magnetic separation, the released Au NPs labeled capture DNA-2 is hybridized with the capture DNA-1 to enhance the ECL signal of CdS NC film. This approach could sensitively detect HL-60 cells with a linear calibration range from 20 to 1.0 × 106 cells/mL.

► Au NPs were used to enhance the ECL of CdS NC film through energy transfer.
► Aptamer tagged magnetic beads were used as capture and separation tools.
► A detection limit of 20 HL-60 cancer cells per milliliter could be achieved.