Photonic Crystals for Biomolecule Sensing Applications

Photonic crystal (PhC) sensors offer important advantages in molecular diagnostic applications, such as detection of disease-related proteins, genes, and pathogenic viruses, and bacteria. This chapter briefly explains the operation principles of three-dimensional (3D) and two-dimensional (2D) photonic crystals, presents how the PhC structures can be fabricated inexpensively, and demonstrate several key applications as for the detection of biomolecules. These applications are based on four main sensing modalities: reflectometry, fluorescence emission, surface-enhanced Raman scattering, and photoacoustic detection. The chapter discusses the implementations of PhC sensors to facilitate the detection of biomolecules via these venues. For each detection modality, we will elaborate the advantages provided by the PhC sensors in the context of specific applications and sensing performances, such as sensitivity and limit of detection. The PhC-based biosensors not only offer new ways to detect biomolecule with low cost and high throughput but also enable researchers and clinicians to improve exiting lab-based assays to achieve better assay sensitivities.