Research Center for Biomedical and Health Science, Anhui Science and Technology University, Fengyang 233100, PR China; School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
Department of Criminal Science and Technology, Nanjing Forest Police College, Nanjing 210023, PR China.
Biosens Bioelectron. 2019 Apr 15;131:193-199. doi: 10.1016/j.bios.2018.11.029. Epub 2018 Nov 19.
Here we report a highly selective and ultrasensitive DNA biosensor based on electrochemical atom transfer radical polymerization (ATRP) signal amplification and "Click Chemistry". The DNA biosensor was prepared by immobilizing thiol and azide modified hairpin DNAs on gold electrode surface. In the presence of target DNAs (T-DNA), hairpin probes hybridized with T-DNAs to form a duplex DNA, and the ring of hairpin DNA was opened to make azide groups accessible at 3' ends. "Click reactions" proceeded between the azide and propargyl-2-bromoisobutyrate (PBIB) to initiate the ATRP reaction which brought a large number of ferrocenylmethyl methacrylate (FMMA) on the electrode surface. The amount of FMMA was proportional to the concentration of T-DNA and quantified by square wave voltammetry. Combining ATRP signal amplification with "Click Chemistry", the optimized DNA biosensor was capable of detecting 0.2 aM. T-DNA. The preliminary application of the developed DNA biosensor was demonstrated by detecting target DNA in spiked serum samples. The developed DNA biosensor shows great promise for the detection of gene biomarkers.
在这里，我们报道了一种基于电化学原子转移自由基聚合（ATRP）信号放大和“点击化学”的高选择性和超灵敏 DNA 生物传感器。该 DNA 生物传感器通过将巯基和叠氮化物修饰的发夹 DNA 固定在金电极表面来制备。在存在靶 DNA（T-DNA）的情况下，发夹探针与 T-DNA 杂交形成双链 DNA，并且发夹 DNA 的环打开，使得 3'端的叠氮化物基团可接近。“点击反应”在叠氮化物和丙炔基-2-溴异丁酸酯（PBIB）之间进行，引发 ATRP 反应，将大量的二茂铁甲基甲基丙烯酸酯（FMMA）带到电极表面。FMMA 的量与 T-DNA 的浓度成正比，并通过方波伏安法进行定量。通过将 ATRP 信号放大与“点击化学”相结合，优化后的 DNA 生物传感器能够检测到 0.2 aM 的 T-DNA。该 DNA 生物传感器的初步应用通过检测加标血清样本中的靶 DNA 得到了证明。所开发的 DNA 生物传感器在基因生物标志物的检测方面具有广阔的应用前景。
