Real-Time FO-SPR Monitoring of Solid-Phase DNAzyme Cleavage Activity for Cutting-Edge Biosensing
Real-Time FO-SPR Monitoring of Solid-Phase DNAzyme Cleavage Activity for Cutting-Edge Biosensing
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DOI：
10.1021/acsami.8b18756
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发表时间：
2019-02-20
影响因子：
9.5
通讯作者：
Lammertyn, Jeroen
中科院分区：
文献类型：
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作者：
Peeters, Bernd;Daems, Devin;Lammertyn, Jeroen
DNA纳米技术在生物传感器设计中具有巨大的潜力，包括通过DNA折纸的生物传感器表面的纳米结构化、通过适体的靶识别以及基于DNA的信号放大策略。在本文中，我们使用DNA纳米技术描述的第一次的概念，实时固相监测DNAzyme切割活性的检测特异性单链DNA（ssDNA）的光纤表面等离子体共振（FO-SPR）生物传感器。为此，我们首先开发了一种稳健的连接策略，用于用ssDNA拴系的金纳米颗粒功能化FO-SPR生物传感表面，作为DNAzyme的底物。接下来，我们建立了由于10-23 DNAzyme的切割活性引起的SPR信号变化与DNAzyme浓度之间的关系，表明较高DNAzyme浓度的切割动力学更快。最后，我们实现了这个通用的概念，在溶液中的ssDNA目标的生物传感。为此，我们设计了一种DNA酶-抑制剂复合物，由与ssDNA靶互补的内环结构组成，其以受控的方式释放活性DNA酶分子，作为靶浓度的函数。我们证明了可重复的目标检测，理论检测限为1.4 nM，证明所提出的连接策略是通用的基于DNA酶的FO-SPR生物传感概念的关键，在医疗和农业食品领域具有广阔的应用前景。
DNA nanotechnology has a great potential in biosensor design including nanostructuring of the biosensor surface through DNA origami, target recognition by means of aptamers, and DNA-based signal amplification strategies. In this paper, we use DNA nanotechnology to describe for the first time the concept of real-time solid-phase monitoring of DNAzyme cleavage activity for the detection of specific single-stranded DNA (ssDNA) with a fiber optic surface plasmon resonance (FO-SPR) biosensor. Hereto, we first developed a robust ligation strategy for the functionalization of the FO-SPR biosensing surface with ssDNA-tethered gold nanoparticles, serving as the substrate for the DNAzyme. Next, we established a relation between the SPR signal change, due to the cleavage activity of the 10-23 DNAzyme, and the concentration of the DNAzyme, showing faster cleavage kinetics for higher DNAzyme concentrations. Finally, we implemented this generic concept for biosensing of ssDNA target in solution. Hereto, we designed a DNAzyme-inhibitor complex, consisting of an internal loop structure complementary to the ssDNA target, that releases active DNAzyme molecules in a controlled way as a function of the target concentration. We demonstrated reproducible target detection with a theoretical limit of detection of 1.4 nM, proving that the presented ligation strategy is key to a universal DNAzyme-based FO-SPR biosensing concept with promising applications in the medical and agrofood sector.