College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, 410083, People's Republic of China.
Department oft of Obstetrics and Gynecology, The Third Xiangya Hospital of Central South University, Changsha, Hunan, 410013, People's Republic of China.
Mikrochim Acta. 2018 Nov 14;185(12):549. doi: 10.1007/s00604-018-3087-9.
A sensitive method is described for detection of the apoE 4 gene detection which is important for early diagnosis of Alzheimer's disease. It is based on signal amplification by using ferrocene (Fc) capped gold nanoparticles modified with streptavidin. The immobilized oligonucleotide probe captures complementary apoE 4 gene. This is followed by the specific recognition of the GCGC sequences which are hydrolyzed by the restriction enzyme HhaI. Cleavage only occurs at the complementary apoE 4 duplex, while mismatches prevent enzymatic cleavage. Thus, the apoE 4 sequence can be discriminated against other apoE sequences. Benefitting from amplified signal by Fc-capped nanoparticle/streptavidin and the recognition of HhaI, the detection limit is as low as 0.1 pM of the ApoE 4 gene. Four genomic DNA samples extracted from blood were analyzed for the presence of the apoE 4 gene. The approach presented here will provide viable proof-of-principle for an enzyme-assisted electrochemical assay for the apoE 4 gene in genomic DNAs. Graphical abstract Schematic presentation of amplified voltammetric detection of Alzheimer's Disease-related apoE 4 gene from unamplified genomic DNA extracts via ferrocene capped gold nanoparticle/streptavidin.
一种用于检测载脂蛋白 E4 基因的敏感方法，该基因对于阿尔茨海默病的早期诊断很重要。该方法基于使用巯基化的二茂铁修饰的金纳米粒子进行信号放大。固定化的寡核苷酸探针捕获互补的载脂蛋白 E4 基因。然后，特异性识别由限制酶 HhaI 水解的 GCGC 序列。只有在互补的载脂蛋白 E4 双链体上才会发生切割，而错配则阻止酶切。因此，可以区分载脂蛋白 E4 序列与其他载脂蛋白序列。受益于二茂铁封端纳米粒子/链霉亲和素的放大信号和 HhaI 的识别，检测限低至 0.1 pM 的载脂蛋白 E4 基因。从血液中提取的 4 个基因组 DNA 样本用于分析载脂蛋白 E4 基因的存在。这里提出的方法将为基于酶辅助的电化学测定法在基因组 DNA 中测定载脂蛋白 E4 基因提供可行的原理验证。
