酶联放大安培检测基因传感器的封闭方式

Blocking Method in Enzyme-Amplified Amperometric DNA Biosensor

在酶联放大安培检测过程中,酶和碱基链在金电极表面的非特异吸附是导致假阳性结果的主要来源.为减少非特异吸附,分别从封闭时间和封闭方式等考查巯基己醇(MCH)和牛血清白蛋白(BSA)对上述非特异性吸附因素的封闭效果.结果表明,BSA不论是对酶还是碱基链的封闭效果均优于MCH.经优化,确定BSA单一封闭剂(15min)为最佳封闭条件,并可用于急性早幼粒细胞白血病(PML-RARα)融合基因的检测.本方法可有效减少非特异吸附,缩短检测预处理时间,并使检测信号在一定程度上得到放大.

Non-specific absorption of enzyme and nucleotide is a main source leading to the background staining in enzyme-amplified amperometric detection of DNA. To eliminate the background staining in this system, the blocking procedure by mercapto-hexanol （ MCH） and bovine serum albumin （ BSA） was studied systematically. The results show that the anti-fouling effect of BSA is better than that of MCH. A simple and efficient blocking strategy employing BSA as the sole blocking reagent was established and applied in the detection of PMLRARα fusion gene in acute promyelocytic leukemia. It can effectively eliminate the background staining,shorten the pre-processing time,and achieve strong signal amplification.