磁纳米探针检测人绒毛膜促性腺激素

Human Chorionicgonadotropin Measurement Method Based on Magnetic Nanoparticle Probes

采用链霉亲和素包被磁纳米粒子,将生物素标记的特异性抗体偶联在磁纳米粒子上,制备出高特异性的磁纳米探针;利用此探针对人绒毛膜促性腺激素(HCG)进行测定,建立了定量检测蛋白类激素的化学发光分析方法。利用紫外可见分光光度计、透射电镜及动态光散射仪对磁纳米探针进行表征,同时对化学发光实验条件进行优化。在2×10-4mol/L鲁米诺、8×10-4mol/L H2O2,pH=13的优化条件下,将磁纳米探针用于HCG的定量检测。结果表明,所测发光强度与待测HCG浓度之间线性相关,相关系数r为0.9924,线性检测范围由常规板式ELISA的5～200μg/L扩展到0.5～250μg/L;相对标准偏差为3.82%。采用本方法和常规ELISA法同时对34份人血清标本HCG进行测试,两者相关性良好。利用制备的磁纳米探针定量测定微量蛋白类激素,具有灵敏、高效、快捷、检测范围宽等优点,有望应用于其它微量蛋白的检测。

The magnetic nanoparticle probe was prepared by specifically connecting the streptavidin-conjugated magnetic nanoparticles and the antibody of analyte via the strong streptavidin-biotin interaction. Based on the magnetic nanoparticle probes, the concentration of human chorionicgonadotropin （HCG） was detected and a new CL method for of hormone was further established. The performances of the magnetic nanoparticle probes were characterized by UV-Vis spectrometry, transmission electron microscopy and dynamic light scattering. The experimental conditions that affected the chemiluminescence were optimized. The optimal concentrations of luminal and H2O2 were 2×10^-4 mol/L and 8×10^-4mol/L, respectively, and optimal pH was 13. Under the optimized experiment conditions, a linear response of chemiluminescence intensity to HCG concen-tration was obtained with a correlation coefficients of 0.9924. The linear range was from 0.5 to 250μg/L and wider than the conventional ELISA method （5-200μg/L）. The relative standard deviation was 3.8%. Correlation analysis showed that there was significant correlation between the method of magnetic nanoparticle probes and ELISA in 34 clinical samples. The proposed method with characters of sensitive, effective, fast response and wide detection range provided good application prospect in analysis of other ultra-micro protein.