Lab in a tube: a fast-assembled colorimetric sensor for highly sensitive detection of oligonucleotides based on a hybridization chain reaction
Lab in a tube: a fast-assembled colorimetric sensor for highly sensitive detection of oligonucleotides based on a hybridization chain reaction
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DOI：
10.1039/c5ra04613k
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发表时间：
2015-05
期刊：
影响因子：
3.9
通讯作者：
Siqi Zhang;Kun Wang;Zhenyu Li;Zhongmin Feng;Ting Sun
中科院分区：
文献类型：
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作者：
Siqi Zhang;Kun Wang;Zhenyu Li;Zhongmin Feng;Ting Sun
本工作以氯化血红素/G-四链辣根过氧化物酶模拟DNA酶为显色产物，构建了一锅法信号放大策略，用于DNA序列的检测。选择与B型肝炎病毒（HBV）相关的DNA序列作为模型靶标。该无酶无标记生物传感器包含三个寡核苷酸作为靶DNA，发夹结构H1和H2部分互补。应该注意的是，G-四链体结构部分隐藏在发夹结构H2中。在没有THBV存在的情况下，发夹H1和H2由于寡核苷酸末端的互补序列而足够稳定，这使得难以完成自组装。在加入THBV后，THBV与H1的自组装允许H1的其余DNA序列促进H1-H2复合物的形成并将THBV释放到下一个循环。在氯化血红素和K+存在下，H1-H2络合物末端的G-四链体被释放，形成氯化血红素/G-四链体结构，该结构可催化无色四甲基联苯胺（TMB）生成有色产物。溶液的颜色变化可通过分光光度法和肉眼进行定量。在DNA链置换反应（DSDR）中，采用20%乙醇作为缓冲液，加速H1-H2复合物的形成，使检测时间从12 h缩短到1 h。比色传感器的检测限为9.5 pM，线性范围为50 pM至100 nM。
In this work, a one-pot signal amplified strategy was constructed based on generating a hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme as the color product for the detection of DNA sequences. A DNA sequence associated with the hepatitis B virus (HBV) was selected as a model target. The enzyme-free and label-free biosensor contained three oligonucleotide terms as target DNA, hairpin structures H1 and H2 which were partially complementary. It should be noted that the G-quadruplex structure was partially hidden in the hairpin structure H2. In the absence of THBV, hairpins H1 and H2 were stable enough due to the complementary sequences at the end of the oligodeoxynucleotides, which made it difficult to complete the self-assembly. Upon addition of THBV, self-assembly of THBV with H1 allows the rest of the DNA sequence of H1 to facilitate H1–H2 complex formation and releases THBV to the next cycle. In the presence of hemin and K+, the G-quadruplex at the end of the H1–H2 complex was liberated to form a hemin/G-quadruplex structure, which could catalyze achromatous tetramethylbenzidine (TMB) into a colored product. The color change of the solution could be quantitated by spectrophotometry and the naked eye. We also employed 20% ethanol in the buffer to accelerate H1–H2 complex formation in the DNA strand displacement reaction (DSDR), which cut down the reaction time of the detection process from 12 h to 1 h. The detection limit of the colorimetric sensor is 9.5 pM, and the linear range is 50 pM to 100 nM.