A highly sensitive electrochemical immunosensor for hepatitis B virus surface antigen detection based on Hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme-signal amplification
A highly sensitive electrochemical immunosensor for hepatitis B virus surface antigen detection based on Hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme-signal amplification
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DOI：
10.1016/j.bios.2017.02.039
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发表时间：
2017-08-15
影响因子：
12.6
通讯作者：
Salimi, Abdollah
中科院分区：
文献类型：
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作者：
Alizadeh, Negar;Hallaj, Rahman;Salimi, Abdollah
本文以Au薄片为工作电极，Fe3O4磁性纳米颗粒（MNPs）为支撑基质，hemin/ g -四联DNAzyme为信号放大器，制备了一种用于乙型肝炎病毒表面抗原（HBsAg）检测的电化学免疫传感器。首先，将HBs的一抗（Ab(1)）固定在羧基修饰的MNPs表面。然后，将抗体与烷基硫醇/ g -四重体DNA/血红蛋白组装在金纳米粒子上，作为生物条形码纳米粒子探针。蛋白靶夹在固定在MNPs上的HBs的一抗（Ab(1)）和hemin生物条形码AuNPs探针标记的抗体（Ab(2)）之间。Hemin/ g-四联体结构作为HRP模拟dnazyme，显著提高了亚甲基蓝（MB）氧化对H2O2的催化还原效果。MB方波伏安法信号可定量测定HBsAg，线性浓度范围为0.3 ~ 1000 pgmL(-1)，检出限为0.19 pgmL（-1）。由于HRP模拟- dnazyme具有高效的催化活性，该免疫传感器具有较高的灵敏度，具有广阔的临床应用前景，为免疫传感器的开发和疾病的快速诊断提供了新的平台。
Here we prepared an electrochemical immunosensor employing Au sheet as working electrode, Fe3O4 magnetic nanoparticles (MNPs) as supporting matrix and hemin/G-quadruplex DNAzyme as signal amplifier for determination of hepatitis B virus surface antigen (HBsAg). First, the primary antibody of HBs (Ab(1)) was immobilized on the surface of the carboxyl-modified MNPs. Then, the assembly of antibody and alkylthiol/G-quadruplex DNA/hemin on gold nanoparticles was used as bio-bar-coded nanoparticle probe. Protein target was sandwiched between the primary antibody of HBs (Ab(1)) immobilized on the MNPs and hemin bio-barcoded AuNPs probe labeled antibody (Ab(2)). Hemin/G-quadruplex structure as HRP mimicking-DNAzyme significantly improved the catalytic reduction of H2O2 by oxidation of methylene blue (MB). Square wave voltammetry signals of MB provided quantitative measurements of HBsAg with a linear concentration range of 0.3-1000 pgmL(-1) and detection limit of 0.19 pgmL(-1). Due to efficient catalytic activity of HRP mimicking-DNAzyme, the proposed immunosensor exhibited high sensitivity and it holds great promise for clinical application and provides a new platform for immunosensor development and fast disease diagnosis.