A novel ultrasensitive competition strategy for electrochemical and colorimetric cytosensing of acute leukemia cells

Selective and reliable method is of vital importance for acute leukemia detection. In this work, a robust competitive electrochemical and colorimetric cytosensing platform for detection of acute leukemia cells was developed with high sensitivity, selectivity, acceptable rapidity and excellent extensibility. The joint effects of the high catalytic activity of horseradish peroxidase (HRP)-mimiking DNAzyme toward H₂O₂ reduction and the excellent competing reaction contributed to the greatly enhanced sensitivity. Such a dual mode sensing strategy allows for ultrasensitive acute leukemia cytosensing with a detection limit as low as ~ 4 cells and a wide linear response range from 10² to 10⁷ cells per mL. This electrochemical and colorimetric cytosensing approach holds great promise as a new point-of-care diagnostic tool for early detection of human acute leukemia and may be readily expanded to multiplex cytosensing of other cancer cells.