Ultrasensitive electrochemical detection of BCR/ABL fusion gene fragment based on polymerase assisted multiplication coupling with quantum dot tagging

•Polymerase-based target recycling amplification was used for fusion gene detection.•Cascade hybridization is utilized for further signal amplification.•Ultrasensitive biosensor was developed by using anodic stripping voltammetry.

A specially tailored electrochemical biosensor for ultrasensitive detection of BCR/ABL fusion gene was developed with high selectivity, acceptable rapidity and excellent extensibility. Taking advantage of circular strand replacement polymerization, cascade hybridization reaction as well as quantum dot based signal amplification, the proposed biosensor showed high sensitivity with the detection limit down to 2 fM. This strategy offers a great promise to early diagnosis and prognosis of chronic myeloid leukemia.