基于HRP-DAB信号放大系统的压电石英晶体DNA传感器微阵列检测表皮葡萄球菌的研究

目的在已构建的压电压电石英晶体DNA传感器检测系统中引入HRP-DAB生物信号放大系统,提高传感器的检测灵敏度,并基于该系统建立一种表皮葡萄球菌快速检测方法。方法采用自组装技术在压电石英晶体DNA传感器上固定针对表皮葡萄球菌的寡核苷酸探针,将掺入生物素(biotin)-dUTP的表皮葡萄球菌靶DNA与之进行杂交反应,加入HRP-链亲和素(streptavidin)、DAB工作液,观察反应频率变化;对35份表皮葡萄球菌感染的临床标本进行检测,并与传统培养法进行比较。结果该压电石英晶体DNA传感器微阵列检测表皮葡萄球菌的灵敏度为95.5%,特异度为84.6%,正确诊断指数为0.801,检出限为2×102CFU/ml,与血培养法差异无统计学意义(P>0.05)。结论基于HRP-DAB信号放大系统的压电石英晶体DNA传感器微阵列,有效的提高了压电石英晶体传感器检测的灵敏度,可用于临床病原菌感染的快速检测,具有较高的临床推广价值。

Rapid Identification of Staphylococcus epidermidis by HRP-DAB Amplification Based Piezoelectric Quartz Crystal Microbalance DNA Sensor Array

OBJECTIVE To construct a highly effective method to rapidly detect Staphylococcus epidermidis by nanoparticle amplification based piezoelectric quartz crystal microbalance DNA sensor array. METHODS The specific oligonucleotide probe for S. epidermidis was immobilized on the gold surface of DNA sensor with self-assembly method firstly. The HRP and DAB solution was added to react with biotin-DNA complex after probe was hybridized with corresponding target DNA. Then, the frequency shift and reaction time were observed. In addition, we measured 35 clinical samples with both HRP-DAB amplification based piezoelectric quartz crystal microbalance DNA sensor array and bacteria culture to assess the difference between the two methods. RESULTS The sensitivity of nanoparticle amplification based piezoelectric quartz crystal microbalance DNA sensor array was 95.5%, the specificity was 84.6% and the Youden's index was 0.801.There was no difference between two methods (P>0.05). CONCLUSIONS The HRP-DAB amplification based QCM system we designed has the advantages of being rapid and highly sensitive and thus can be a useful supplement to clinical assay methods in rapid identification of pathogenic bacteria infections.