OPTICAL FIBER SURFACE PLASMON RESONANCE (SPR) BIOSENSORS: A COMPREHENSIVE REVIEW OF PRINCIPLES, STRUCTURES, AND RECENT ADVANCES

In recent years, optical fiber-based surface plasmon resonance (SPR) sensors have gained significant attention in biochemical sensing applications due to their high sensitivity, realtime detection capability, and strong selectivity.Current advancements in this field focus primarily on enhancing sensor sensitivity, improving measurement accuracy, and expanding the ability to detect a wider range of biological analytes.This paper provides a comprehensive overview of recent progress in optical fiber SPR biosensors.It begins by discussing the fundamental principles and structural configurations of fiber-optic plasmonic sensors, with emphasis on three major categories: surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and long-range surface plasmon resonance (LRSPR).Each sensing mechanism is explained based on its underlying physical concepts and its integration within optical fiber platforms.Finally, the paper highlights emerging research trends in the development of fiber-optic SPR biosensors and offers insights into future directions aimed at improving performance, miniaturization, and applicability in advanced biochemical detection.