一种无需酶的电化学生物传感器,用于同时检测两种血友病 A 生物标志物:通过目标物循环和量子点封装的金属有机框架进行信号放大的组合。
An enzyme-free electrochemical biosensor for simultaneous detection of two hemophilia A biomarkers: Combining target recycling with quantum dots-encapsulated metal-organic frameworks for signal amplification.
机构信息
Genetics Division, Biology Department, Faculty of Sciences, University of Isfahan, Isfahan, 81746-73441, Iran.
Genetics Division, Biology Department, Faculty of Sciences, University of Isfahan, Isfahan, 81746-73441, Iran.
出版信息
Anal Chim Acta. 2019 Dec 27;1092:66-74. doi: 10.1016/j.aca.2019.09.037. Epub 2019 Sep 16.
A sensitive and selective electrochemical method for simultaneous detection of two hemophilia A-related microRNAs (miR-1246 and miR-4521) was developed. This detection tactic was based on gold nanoparticles (AuNPs), heavy metals quantum dots-encapsulated metal-organic frameworks (QDs@ZIF-8), and catalytic hairpin assembly (CHA) for signal application. Primarily, hairpins H1 and H2 were hybridized with targets miR-1246 (T1) and miR-4521 (T2) for forming H1-T1 and H2-T2 duplex stranded DNAs (dsDNAs) that were able to open the hairpins H3 and H4 for the formation of H1-H3 and H2-H4 dsDNAs. Meanwhile, lots of H1-H3 and H2-H4 dsDNAs were created by releasing the target to take part in the next cycle for signal amplification. And then single stranded fragments of H1-H3 and H2-H4 dsDNAs were utilized for hybridizing the PbS@ZIF-8-S1 and CdS@ZIF-8-S2 in order to amplify the electrochemical signal. The diagnosis of corresponding target miRs using differential pulse voltammetry has been possible by releasing Pb (II) and Cd (II) ions from PbS@ZIF-8 and CdS@ZIF-8 tags by HCI leaching. In this context, encapsulation of heavy metals quantum dots (QDs) was done in zeolitic imidazolate framework-8 (ZIF-8) to form QDs@ZIF-8 muti-core-shell particles by in situ growth of ZIF-8 in the presence of QDs. Since the quantity of QDs tagged to each target miRs grows massively, being resulted from a huge number of QDs that encapsulated in each QDs@ZIF-8 label, the sensitivity of the biosensor using QDs@ZIF-8 particles as signal tags is about 15 times that of a biosensor using QDs as signal tags. Several conditions of determination like incubation time for labeling and capture probe, HCl leaching time, and reaction time of CHA were optimized. Under the optimized conditions, this assay allowed the detection of target miRs in the range of 1 fM to 1 μM with detection limits of 0.19 fM and 0.28 fM for miR-1246 and miR-4521 (S/N = 3). The biosensor can discriminate complementary, 1-base mismatched and non-complementary sequences quite well, according to the catalytic hairpin assembly. Furthermore, the biosensor was utilized efficiently for quick and direct analysis of microRNAs in human serum. Thus, this tactic presents an innovative platform for microRNAs expression profiling in biomedical research and clinical diagnosis.
一种灵敏且选择性的电化学方法被开发出来,用于同时检测两种血友病 A 相关的 microRNAs(miR-1246 和 miR-4521)。这种检测策略基于金纳米粒子(AuNPs)、重金属量子点封装的金属有机骨架(QDs@ZIF-8)和催化发夹组装(CHA)进行信号应用。首先,发夹 H1 和 H2 与靶标 miR-1246(T1)和 miR-4521(T2)杂交,形成 H1-T1 和 H2-T2 双链 DNA(dsDNA),这些 dsDNA 能够打开发夹 H3 和 H4,形成 H1-H3 和 H2-H4 dsDNA。同时,通过释放目标物参与下一个循环进行信号放大,产生大量的 H1-H3 和 H2-H4 dsDNA。然后,利用 H1-H3 和 H2-H4 dsDNA 的单链片段与 PbS@ZIF-8-S1 和 CdS@ZIF-8-S2 杂交,以放大电化学信号。通过 HCl 浸出从 PbS@ZIF-8 和 CdS@ZIF-8 标签中释放 Pb(II)和 Cd(II)离子,使用差分脉冲伏安法可以对相应的靶标 miR 进行诊断。在此背景下,通过在存在量子点的情况下原位生长 ZIF-8,将重金属量子点(QDs)封装在沸石咪唑酯骨架-8(ZIF-8)中,形成 QDs@ZIF-8 多核壳颗粒。由于每个目标 miR 标记的 QDs 数量大量增加,这是由于每个 QDs@ZIF-8 标签中封装的大量 QDs 所致,因此使用 QDs@ZIF-8 颗粒作为信号标签的生物传感器的灵敏度约为使用 QDs 作为信号标签的生物传感器的 15 倍。优化了测定条件,如标记和捕获探针的孵育时间、HCl 浸出时间和 CHA 的反应时间。在优化条件下,该测定法可在 1 fM 至 1 μM 的范围内检测到靶标 miR,检测限分别为 miR-1246 和 miR-4521 的 0.19 fM 和 0.28 fM(S/N=3)。根据催化发夹组装,该生物传感器能够很好地区分互补、1 碱基错配和非互补序列。此外,该生物传感器还可有效地用于快速直接分析人血清中的 microRNAs。因此,该策略为生物医学研究和临床诊断中的 microRNAs 表达谱分析提供了一个创新的平台。