Investigation of Probe DNA Immobilization Method for Label-free DNA Biosensing Using Polymer-based Photonic Crystal

Abstract

Polymer-based photonic crystals (PhCs) were fabricated using nanoimprint lithography for use as DNA biosensors by immobilizing the probe DNA. Polymer-based PhCs can be applied to cost-effective and label-free DNA biosensors. Additionally, DNA hybridization can be detected using inexpensive and simple optical systems. In this study, probe DNA was immobilized on the PhC surface using electrostatic adsorption or covalent bonding, and the sensing performance was compared. Consequently, the PhC biosensor prepared using covalent bonding exhibited greater DNA-hybridization-induced reflection intensity changes than that prepared using electrostatic adsorption. Furthermore, discrimination of reflection intensity for target and mismatch DNA was investigated, which revealed that in contrast to the PhC biosensor prepared using the electrostatic adsorption of probe DNA, that prepared using covalent bonding discriminated target DNA at a concentration of 0.1 nM.