Localized surface plasmon resonance based label-free optical biosensor for monitoring peptide nucleic acid-DNA hybridization

In recent years, label-free biosensors not requiring external modifications have been receiving intense attention. A label-free optical sensor, which retains many of the desirable features of conventional Surface Plasmon Resonance (SPR) reflectometry, namely, the ability to monitor the kinetics of biomolecular interactions in real-time without a label has been developed with several important advantages: the sensor is easy to fabricate, and simple to implement, requiring only an UV-visible spectrophotometer or a flatbed scanner. Importantly, the sensor can be easily multiplexed to enable high-throughput screening of biomolecular interactions in an array-based format. In this research, the development of a label-free optical biosensor based on localized surface plasmon resonance (LSPR) using gold-capped nanoparticle layer substrate is described. This optical monitoring method promises to offer a massively parallel detection capability in a highly miniaturized package. The two-dimensional nanoparticle layer was formed by the surface modified silica nanoparticles. The optical properties of gold-capped nanoparticle layer substrate were characterized through transmission measurements. In this research, monitoring the Peptide nucleic acid (PNA)-DNA hybridization and single-base mismatch detection using this gold-capped nanoparticle layer substrate was carried out.