Silicon Photonic Biosensors in Clinical Diagnostics: Emerging Opportunities and Challenges

As health care systems worldwide seek to decentralize diagnostics and expand precision medicine, silicon photonic biosensors have become a compelling solution. Their development over the past decade, especially in the last 5 years, marks a significant convergence of photonics, nanotechnology, and biomedical engineering that aims to reshape the diagnostic landscape. This review presents a comprehensive analysis of advances in silicon photonic biosensors, focusing on key configurations including microring resonators, photonic crystals, interferometers, and other emerging transduction mechanisms. We discuss the integration of advanced surface functionalization strategies for efficient and robust bioreceptor immobilization, which is critical for reliable biomedical applications. We emphasize the translation of these devices into clinical settings, primarily in infectious diseases and cancer diagnostics. Finally, we address current limitations, such as fabrication complexity, microfluidic integration, and data interpretation, and outline future directions to enhance scalability and clinical adoption in personalized medicine and decentralized health care.