High-Resolution Optical Chromatography: Principles, Innovations, and Emerging Biomedical Applications.

Optical chromatography (OC) has emerged as a powerful, label-free technique for the precise manipulation and separation of micro- and nanoparticles based on their intrinsic biophysical properties, including size, refractive index, and morphology. By balancing optical radiation pressure with fluid drag forces, OC enables high-resolution sorting of diverse analytes-from synthetic colloids to biological cells and pathogens-without the need for fluorescent labels or chemical modifications. Recent advancements in integrated optofluidic platforms, such as plasmonic microlens arrays, fiber-based systems, and hybrid optical-electrical detection approaches, have significantly enhanced OC capabilities, addressing long-standing challenges in scalability, throughput, and sensitivity, and facilitated its transition toward compact, application-oriented analytical platforms. These innovations have expanded OC applications in critical biomedical fields, including exosome isolation, pathogen detection, and viral infection monitoring. Furthermore, the integration of OC with tunable resistive pulse sensing (TRPS) presents a promising avenue for simultaneous particle fractionation and characterization, overcoming key limitations of conventional resistive pulse techniques. In this review, we provide a comprehensive overview of the fundamental principles of OC, followed by recent progress in particle separation strategies and integrated optofluidic system design. We further highlight emerging applications in bioanalysis and discuss future directions toward high-throughput, multimodal, and clinically relevant OC platforms.