基于双抗体夹心传感膜的信号增强方法用于致癌基因c—myc蛋白的检测

采用层层自组装方法，制备了一种基于双抗体夹心层修饰金电极的信号增强电化学生物传感器，即先通过组装L-半胱氨酸、戊二醛，固定c—Myc（9E10）单克隆抗体（C．AbI），形成C．Ab1单抗修饰电极，可识别致癌基因c—myc蛋白；再结合上第二抗体羊抗鼠免疫球蛋白G抗体（c．Ab2），形成C．Ab1／c—myc／C—Ab2双抗夹心修饰电极，响应信号大幅度增强，传感性能优于C—A1单抗修饰电极．通过电化学阻抗和循环伏安行为探讨了双抗夹心法信号增强的机理，其阻抗值与c．myc浓度对数在0．043-430nM范围内成良好的线性关系，线性方程可拟合为Y=10046．10＋863．33墨线性相关系数为0．9904，c—myc的最低检测限也降低至25．76pM．该传感器制备简单，选择性、重现性、稳定性和再生性好，在鼠血清样品中测得c—myc的回收率在97．4％-103．7％之间，表明该方法可用于实际肿瘤样品中c—myc的检测，在生物医学领域具有潜在的应用价值．

Determination of c-myc oncogene protein based on double antibody sandwich sensing film for signal enhancement

A kind of signal enhanced electrochemical biosensor based on double antibody sandwich film modified Au electrode was prepared by using layer-by-layer self-assembly technique. The Au electrode was firstly assembled with L-cysteine and glutaraldehyde, then fixed with c-Myc （9El0） monoelonal antibody （C-Abl）, resulting in forming a C-Abl modified electrode, which was able to recognise the c-myc oncogene protein. After combining with a second antibody of anti-mouse IgG （H＋L） antibody （C-Ab2）, the double antibody sandwich film （C-Abl/c-myc/C-Ab2） modified electrode was obtained, in which the response signal was greatly enhanced, and the sensing property was better than that of the C-Abl modified electrode. The mechanism for signal enhancement with the double antibody sandwich method was explored through electrochemical impedance analysis and cyclic voltammetry behaviors. The impedance value of C-Abl/c-myc/C-Ab2 modified biosensor was linearly proportional to the logarithmic concentrations of c-myc protein over the range of 0.043-430 nM, and the linear equation was fitted as Y = 10046.10 ＋ 863.33X with a correlated coefficient of 0.9904. The detection limit of c-myc protein was evaluated to be 25.76 pM The biosensor was simply prepared which possessed nice selectivity, reproducibility, stability and regenerability, and could be applied for determination of c-myc in rat serum with a recovery from 97.4% to 103.7%, indicating its practical application on detection of c-myc in tumor samples with potential value in biomedical field.