Photonic Crystal Grating Resonance and Interfaces for Health Diagnostic Technologies

The photonic crystal grating resonance (PCGR) technologies mark a significant advancement in early diagnostics of infectious diseases. Here we review the historical perspectives of the PCGR-based platform starting from the early 1900s, discussing the fundamental principles, fabrication strategies, properties, and multifaceted applications. We delve into the significance of grating-based PC interfaces, from the perspective of plasmonics, photonics, and hybrid photoplasmonic interfaces. Hybrid substrates combining PCGR with plasmonic films, dielectric mirrors, and gratings extend the versatility of these platforms. The relevance of PCGR substrates in sensing various bioanalytes, from microRNA to proteins and lipids, is discussed using several case studies. Multifaceted applications such as photonic resonator absorption microscopy (PRAM), photonic resonator interferometric scattering microscopy (PRISM), and photonic crystal enhanced fluorescence (PCEF) showcase the transformative impact of PCGR substrates in the biosensing portfolio. An added advantage of accessibility and convenience of these technologies stemming from integrating smartphone-based detection is succinctly captured. A comparative analysis of PCGR-based biosensing highlighting their strengths and limitations, paving the way for future scope and opportunities, is discussed reviewing the literature in the past 25 years. In conclusion, this review provides a comprehensive overview of PCGR technologies, offering insights into their current state, challenges, and prospects for future advancements.