Evolution of Photonic Crystal Fiber-Based Smart Sensors With Emphasis on Biomedical Applications: A Review

Photonic crystal fiber (PCF) based surface plasmon resonance (SPR) sensors have emerged as powerful groundbreaking platforms for smart biomedical sensing due to their exceptional light–matter interaction, structural tunability, and high sensitivity. This review presents a concise and critical overview of recent advances in PCF SPR sensing technologies with a primary focus on biomedical applications, including disease biomarkers, proteins, DNA, glucose, and pathogenic microorganisms’ detection. Smart sensing capabilities such as real-time monitoring, miniaturization, multiplexed detection, and enhanced sensor selectivity have been systematically analyzed. Key sensor performance parameters, including…