Plasmon-based SMSMS optical fiber sensor structure for creatinine detection in aquaculture industry

In this study, a plasmon sensor based on a core mismatch optical fiber structure is proposed for measuring various creatinine concentrations. Creatinine is an important clinical biomarker for diabetes, kidney disease, renal failure, and muscle atrophy. The single-mode fiber (SMF) and multi-mode fiber (MMF) are used to fabricate the SMF-MMF-SMF-MMF-SMF (SMSMS) structure. Further, SMSMS fiber structure is etched with hydrofluoric (HF) acid, that results in more evanescent fields at the core-cladding interface. Gold nanoparticles (AuNPs) are immobilized on the surface of the optical fiber structure to activate the LSPR phenomenon. To validate the sensor's performance, the sensor's sensitivity, reusability, reproducibility, and selectivity are tested. The experimental results demonstrate that the fiber-optic sensor based on the SMSMS structure is capable of measuring creatinine concentrations over a wide range in aquaculture industry. This provides an excellent opportunity for the sensor to be used in biomedicine.