Fabrication Of ECL Carbohydrate Biosensor And Its Applications

Cell surface glycoproteins and glycolipids play crucial roles in cell communication and differentiation,signaling,immunological recognition,and metastasis among other processes.The glycan expression on cell surface is a dynamic process associated with the cellular condition and status and reflects the pathophysiological steps of the morbid state.Glycan epitopes are generally the surface markers to detect and recognize specific types of cells,such as tumor cells and normal cells.Electrogenerated chemiluminescence(ECL)technique which not only presents high sensitivity and wide dynamic concentration response range but also is potential-and spatial-controlled has been widely applied in immunoassays,DNA analysis and clinical diagnosis.With the development of nanotechnology,much attention has been centered on nanomaterials owing to their unique physical and chemical properties.Nanomaterials has been used in ECL biosensors which acts as an electrode material or ECL signal molecules to improve the performance of ECL biosensor.Rapid development has been made in ECL biosensors in dynamic process analysis of cell surface,specially the glyco-ECL biosensor based on the interaction between glycan and lectin.This article mainly contains two parts as follows:1.Exfoliation of MoS2 were prepared by intercalation method.rMoS2 was made by electrochemical reduction as electrode modifies material.An electrogenerated chemiluminescence(ECL)biosensor was fabricated for cell dection.As excellent ECL properties of C3N4 QDs at negative potential,the as-proposed biosensors exhibits excellent analytical performance towards the cytosensing of MCF-7 cells with a linear range from 1.0 × 102 to 1.0 × 107 cells mL-1 and a detection limit of 35 cells.2.A novel reusable and dual-potential responsive electrogenerated chemiluminescence(ECL)biosensor was fabricated for synchronous detection of cancer cells and their surface N-glycan.In this strategy,two analysis method including competitive assay based positive ECL probe Ru(phen)32+ and sandwich-type assay based on negative ECL probe Con A@Au-C3N4 were constructed.The cytosensing and cell surface N-glycan evaluation could be simultaneously realized with high sensitivity and excellent selectivity.Based on the ratio of ECL intensity between the negative potential and positive potential(ΔECLn/ΔECLp),dynamic analysis of the N-glycan on cell surface could be realized avoiding the traditional routing cell counting procedures.As a proof-of concept,the ECL cytosensor showed excellent performances for the analysis of the MCF-7 cancer cell and its surface N-glycan evaluation in human serum sample.Moreover,the aptamer modified electrode can be regenerated in the presence of capture DNA solutions for cyclic utilization.The reusable and dual potential response ECL biosensor endows a feasibility tool for microfluidique and combined analytical instrument.