Peptide-conjugated hemin/G-quadruplex as a versatile probe for “signal-on” electrochemical peptide biosensor
Peptide-conjugated hemin/G-quadruplex as a versatile probe for “signal-on” electrochemical peptide biosensor
复制标题
肽缀合血红素/G-四联体作为“信号开启”电化学肽生物传感器的多功能探针
DOI：
10.1016/j.talanta.2019.120611
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发表时间：
2020
期刊：
影响因子：
6.1
通讯作者：
Baoxian Ye
中科院分区：
文献类型：
--
作者：
Zhuo Ye;Gaiping Li;Lingling Xu;Qian Yu;Xiaoyue Yue;Yongmei Wu;Baoxian Ye
本工作基于多肽偶联氯化高铁血红素/G-四链(DNAzyme-多肽)和玫瑰花蕾状MoSe2@还原石墨烯氧化物(MoSe2@rGO)纳米复合材料，研制了一种新型的用于前列腺特异性抗原(PSA)检测的“信号导通”电化学肽生物传感器。有趣的是，该多肽不仅可以作为PSA的识别探针，还可以作为增强剂来提高氯化血红素/G4的酶活性，从而提高了检测的灵敏度。加入PSA，切割Fe3O4标记的脱氧核酶-多肽探针，然后进行磁分离。通过多肽的羧基和半胱氨酸的氨基相互作用，将切割后的脱氧核酶多肽捕获到半胱氨酸修饰的电极上。从氯化高铁血红素中获得了很强的电化学信号，并进一步利用脱氧核酶-多肽的增强电催化作用进行了放大。与原来的DNAzyme相比，DNAzyme-肽在信号放大方面表现出3倍以上的增强。而MoSe2@rGO由于其良好的导电性和较大的比表面积而放大了电化学信号。因此，该方法可以将PSA检测到0.3fg/m L以下，避免了使用昂贵的蛋白酶和额外的电活性物种，具有操作简单、成本低的优点。因此，该生物传感器有可能为检测PSA早期诊断癌症提供一种非常有效的工具。
In this work, a novel “signal-on” electrochemical peptide biosensor based on peptide-conjugated hemin/G-quadruplex (DNAzyme-peptide) hybrid and rosebud-like MoSe2@reduced graphene oxide (MoSe2@rGO) nanocomposite, was developed for detection of prostate-specific antigen (PSA). Interestingly, the peptide not only served as recognition probe to detect PSA, but also acted as the enhancer to improve the enzyme activity of hemin/G4, which promoted the detection sensitivity. Up addition of PSA, Fe3O4-labeled DNAzyme-peptide probe was cleaved, followed by the magnetic separation. The cleaved DNAzyme-peptide was then captured onto the cysteine-modified electrode via the interaction between carboxyl groups of peptide and amino group of cysteine. A strong electrochemical signal was obtained from hemin and further was amplified by the enhanced electrocatalysis of DNAzyme-peptide. Compared to the original DNAzyme, DNAzyme-peptide exhibited more than 3-fold enhancement in signal amplification. And MoSe2@rGO amplified the electrochemical signal due to its good conductivity and large surface area. So the proposed strategy detected PSA down to 0.3 fg/mL, and it showed the advantages of simplicity, low cost by avoiding the use of expensive protein enzyme and additional electroactive species. Therefore, the proposed biosensor potentially provided a very effective tool for early diagnosis of cancer by the detection of PSA.