Parvovirus B19 (B19V) and human bocavirus (HBoV) are notable dangerous human pathogens based on ssDNA, which cause infectious diseases. Although label-free molecular level quantification of these pathogens is extremely challenging, it can be achieved by trending surface plasmon resonance (SPR) sensor. Here, a graphene-based plasmonic chip, essential in the SPR sensor, is developed for the specific label-free detection of ssDNA based pathogens. The absorption curves reveal that graphene has a significantly stronger interaction with ssDNA than the plasmonic metal due to π-stacking bonding with carbon rings of nucleobases present in ssDNA. Further, reflectance curves show that shift in resonance angle for graphene is more than twice without graphene even for very low concentration, i.e., 0.23 μM of the target ssDNA. Additionally, the penetration depth of the electric field in the sensing medium for graphene is 2.5 times of the plasmonic metal, i.e., silver, which makes it suitable for the detection of comparatively larger molecules. The combination of extraordinary chemical bonding and optical properties of graphene represents a highly sensitive detection of DNA hybridization. It provides a confident track for the diagnosis of ssDNA based infectious diseases.

中文翻译：

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使用基于石墨烯的等离子体传感器芯片进行 DNA 杂交的实验演示

细小病毒 B19 (B19V) 和人类博卡病毒 (HBoV) 是基于 ssDNA 的值得注意的危险人类病原体，它们会引起传染病。尽管这些病原体的无标记分子水平量化极具挑战性，但可以通过趋势表面等离子体共振 (SPR) 传感器来实现。在这里，SPR 传感器中必不可少的基于石墨烯的等离子体芯片被开发用于基于 ssDNA 的病原体的特定无标记检测。吸收曲线表明，由于与 ssDNA 中存在的核碱基碳环的 π 堆积键合，石墨烯与 ssDNA 的相互作用明显强于等离子体金属。此外，反射曲线显示，即使在非常低的浓度下，即 0.23 μM 的目标 ssDNA，石墨烯的共振角偏移也超过两倍，没有石墨烯。此外，电场在石墨烯传感介质中的穿透深度是等离激元金属银的2.5倍，适合检测较大的分子。石墨烯非凡的化学键合和光学特性的结合代表了对 DNA 杂交的高度灵敏的检测。它为基于 ssDNA 的传染病的诊断提供了可靠的途径。