Quantitative analysis of albumin and glucose based on near-infrared fibre-optic SPR sensing

Abstract

Blood component analysis is a critical tool for disease diagnosis. Infrared spectroscopy, combined with fibre optic sensing, offers rapid, non-destructive, and accurate blood biochemical analysis; however, traditional devices face challenges in miniaturisation, cost, and noise interference. This study developed a near-infrared fibre optic SPR sensing system to address these issues, optimising fibre processing and coating for enhanced performance in clinical diagnostics. Fibres were etched with HF acid to vary core diameters, and silver nanoparticles were modified on fibre surfaces under different pH conditions. A multimode fibre-based SPR system was constructed for the quantitative analysis of albumin and glucose, and the results were compared with those obtained using a spectrometer. Fibres etched for 80 min with silver nanoparticles (approximately 45 nm) in a pH nine environment achieved optimal detection, enhancing sensor sensitivity via surface plasmon effects. A comparative analysis showed that the SPR system outperformed the spectrometer. For albumin, the spectrometer yielded an Rp of 0.8693 and RMSEP of 467.738 mg/dL, while the SPR system achieved an Rp of 0.8980 and RMSEP of 427.5705 mg/dL. For glucose, the spectrometer recorded an Rp of 0.5951 and RMSEP of 96.3892 mg/dL, whereas the SPR system achieved an Rp of 0.9073 and RMSEP of 56.7273 mg/dL. These findings indicate that the silver nanoparticle-modified fibre-optic SPR system offers superior accuracy and stability compared to conventional spectroscopy, providing a high-precision, portable solution for blood biochemical analysis.