基于NaOH刻蚀玻碳电极的电化学传感器在检测膀胱癌DNA中的应用

制备了一种基于活化的玻碳电极的新型电化学DNA生物传感器,可用于膀胱癌DNA的检测.通过循环伏安法(CV)实现玻碳电极在NaOH溶液中的刻蚀,使电极表面负载大量官能团,为DNA提供连接位点,由Laviron方程计算得到玻碳电极表面的羧基浓度为 1.022×10-6 mol/cm2.亚甲基蓝(MB)作为电化学检测的杂交指示剂.采用原子力显微镜(AFM)对刻蚀后的电极进行了形貌表征.在最优杂交条件下,通过差分脉冲法(DPV)计算出最佳检测限为5.677×10-13 mol/L(n=5),适用目标 DNA浓度范围1×10-8 mol/L~1×10-12 mol/L.该传感器有望用于实际样品中膀胱癌DNA的快速检测.

A sensitive electrochemical biosensor based on NaOH etched glassy carbon electrode for detection of bladder cancer DNA

In this paper,a novel and sensitive electrochemical DNA biosensor based on activated glassy carbon electrode(GCE)for detection of bladder cancer DNA.GCE was activated by etching in NaOH solution by cyclic voltammetry(CV)for providing the electrode surface with abundant functional groups for DNA attachment,the average surface concentration of carboxyl groups on electrode surface is about 1.022×10-6 mol/cm2(Laviron's equations).Methylene blue(MB)was used as hybridization indicator for electrochemical detection.Atomic force microscope(AFM)analysis was employed for the morphological performance of activated electrode surface.Under the optimal hybridization conditions,differential pulse voltammetry(DPV)responses of the biosensor were in linear with the target DNA in the concentration range from 1×10-12 mol/L to 1×10-8 mol/L with the detection limit as 5.677×10-13 mol/L(3δ).This sensor will be promising for the fast detection of bladder cancer DNA in real sample.