Detection Of BCR/ABL Fusion Gene Based On MNAzyme-Mediated Target-Cycling And SsDNA-Assisted Cascade Hybridization Reaction

Chronic myelogenous leukemia?CML?,a clonal myeloproliferative sickness caused by the neoplastic process of the pluripotent hematopoietic stem cell,is a great threat to human health and life.It is still difficult in early diagnosis on account of most CML patients show no distinguishable symptoms in their initial phase in 3-5 years.According to the classification criteria of leukemia revised by the world health organization?WHO?in2016,the fusion gene BCR/ABL is a key driver of the occurrence and development of CML.In addition,the confirmed exist of fusion gene is also important for the molecular diagnosis of leukemia.Therefore,fusion gene is not only the important marker for leukemia diagnosis,classification and therapeutic evaluation,but also the key to accurate medical detection of leukemia.A novel and simple electrochemical strategy has been developed for ultrasensitive and specific detection of BCR/ABL fusion gene based on multi component nucleic acid enzyme?MNAzyme?and ssDNA-assisted cascade hybridization reaction.In the presence of Mg²⁺,a stable active MNAzyme was formed by the homogeneous recognition and specific binding with the target,initiating shear reaction of hairpin probe?HP?to produce numerous triggers.These triggers could hybridize with the immobilized capture probes and the biotinylated P1 and P2,which caused the heterogeneous ssDNA-assisted cascade hybridization reaction on the surface of the electrode.Binding with the biotin-rich long concatamers structure,streptavidin-alkaline phosphatase?ST-AP?could catalyze a-naphthyl phosphate?a-NPP?to produce amplified electrochemical signals.The electrochemical DNA biosensor showed high sensitivity for target gene with detection limit of 21.9 fM.In addition,the established biosensor was successfully applied for detecting target BCR/ABL gene in complex samples.Thus,the electrochemical biosensing strategy presents a simple and pragmatic thinking toward ultrasensitive fusion gene detection in chronic myelogenous leukemia?CML?diagnosis.