【摘要】 人/动物发病初期的免疫检测在疾病诊断和防治领域具有重要意义.发病初期病患血清中抗体浓度较低,而传统检测方法单纯依靠抗体自身的随机运动使之与抗原结合发生特异性免疫反应,需要数小时甚至更长的时间才能识别出阳性血清,不利于疾病的快速诊断.因此加快对血清中低浓度抗体的检测速度是提高临床诊断效率的关键因素.本文提出基于交流电热和介电泳技术的血清中低浓度抗体快速检测的新方法,搭建"硅基底非对称平行电极阵列-PDMS微通道"微流控测试平台,以牛副结核为例,通过对免疫反应过程中"电极/血清"界面双电层电容的实时测量,以单位时间内电容的相对变化率为指标,成功分辨出阴性和阳性血清,检测时间仅为2 min.结合交流电场下微流体的流动和可极化粒子的介电泳理论,分析了免疫反应加快的机理.交流电场加速了微通道内抗体分子的对流和传质,大幅度提高了免疫反应效率,结合免疫反应方程,给出了免疫检测过程中微通道内抗体浓度变化的数值仿真,在理论上证明了快速血清免疫检测新方法的可行性.更多还原

【Abstract】 Early immunoassay is essential at the beginning of human/animal disease diagnosis. Due to limited concentration of antibody and slowly nature diffusion, it takes hours or more time to detect the disease specific antibody in serum using traditional diagnosis methods. A novel approach is proposed to enhance the convection and mass transfer in the micro channel based on AC electroth- ermal effect and dielectrophoresis, improving the antigen-antibody specific binding efficiency greatly, even the antibody in the serum at low concentration level. A platform with interdigited electrode array on silicon wafer and PDMS micro channel is developed for bovine paratuberculosis(Johne’s Disease) rapid diagnosis. It only takes 2 minutes to distinguish positive serum from negative ones by measuring the change of electrode/serum interfatial electrical double layer capacitance at real time. Ac electric field enhanced rapid serum immunoassay diagnosis mechanism is presented based on AC electrolthermal and dielectrophoresis theory. Convection and mass transfer is greatly enhanced by AC electric field, leading to a rapid specific binding. The change of disease specific antibody concentration in the micro channel is simulated, showing validity of the novel rapid immunoassay diagnosis method.更多还原