Construction Of An Electrochemical Biosensor For The Detection Of Epithelial-mesenchymal Transition

Epithelial-mesenchymal transition(EMT)refers to the process by which epithelial cells are transformed into cells with a mesenchymal phenotype.This process involves changes in a variety of biological characteristics.Through EMT,epithelial cells lose their polarity,lose their connection to the basement membrane,have a higher ability to migrate and invade,resist apoptosis,and degrade the extracellular matrix.In addition,in the process of tumor metastasis,through the EMT process,tumor cells can acquire the characteristics of tumor stem cells,which is one of the molecular mechanisms for tumor progression and heterogeneity.Significant progress has been made in the diagnosis and treatment of cancer in the clinic;however,tumor metastasis is still a barrier to successful cure of cancer and a main cause of cancer death.Therefore,elucidating the molecular mechanism that regulates the occurrence of EMT in malignant tumor cells and clarifying its pathological significance in the occurrence,development,and metastasis of malignant tumors may help to provide new strategies for early diagnosis and management of cancer.Electrochemical biosensors have been widely used in clinical medicine,food safety,and environmental monitoring with the advantages of fast speed,high sensitivity,and high specificity.Compared with traditional technology for tumor detection and diagnosis,electrochemical biosensors can successfully differentiate tumor cells from normal cells,and local tumor cells from circulating tumor cells.In this study,firstly,the traditional experimental methods Western-blotting and immunofluorescence experiments were used to characterize the EMT model and itsdifferent stages produced by TGF-induced cells.Subsequently,a simple electrochemical biosensor for specifically detecting changes in E-cadherin,a molecular marker of EMT,was constructed using the unique properties of quantum dots(QDs),nanocomposites,and electrochemical sensing technology.This electrochemical biosensor can effectively analyze EMT and its different stages.Multi-walled carbon nanotube-gold nanoparticle composite materials modify the glassy carbon electrode to improve its electrical conductivity,and QDs combined with E-cadherin antibody to construct electrochemical probe for specific analysis of EMT model.Differential pulse voltammetry reveals that the electrochemical signal response is fast and sensitive,due to the synergistic effect of QDs and multiwall carbon nanotube-gold nanoparticles.In addition to the detection of cancer-related EMT,the complex behavior of cell movement and cell type transition during the occurrence of EMT and the analysis and detection of cells and EMT model in complex environment also prove the wide applicability and practicality of our electrochemical biosensors.This study has the potential to promote the application of electrochemical biosensor technology in the detection of complex biological behaviors.