Experimental Demonstration of DNA Hybridization Using Graphene Based Plasmonic Sensor Chip

Abstract

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.