A Novel Surface Plasmon Resonance Imaging (SPRi) Biosensor for the Determination of Bovine Interleukin-10: Development, Validation, and Application in Biological Fluids.

Interleukin-10 (IL-10) is a pleiotropic cytokine that is pivotal in regulating the immune response. Its involvement in the pathophysiology of bovine diseases and its potential influence on oocyte developmental competence make it an important target for diagnostics and research. This study aimed to develop and validate a novel, rapid, and sensitive analytical tool for its quantification. A specific biosensor based on Surface Plasmon Resonance Imaging (SPRi) was developed for the precise quantification of bovine IL-10, utilizing a polyclonal rabbit antibody immobilized on a gold chip for direct capture from complex biological matrices. The method was validated for its analytical performance, including linearity, sensitivity, precision, and selectivity. The developed method is characterized by a wide diagnostic range (1-1000 pg/mL) and high sensitivity, with a limit of detection (LOD) of 0.45 pg/mL and a limit of quantification (LOQ) of 1.49 pg/mL. The biosensor was successfully applied to measure IL-10 concentrations in bovine serum and follicular fluid, revealing significantly higher levels in follicular fluid. The validated SPRi biosensor is a rapid, sensitive, and cost-effective tool for determining IL-10 levels. Its successful application confirms its utility for veterinary diagnostics and highlights its potential for research in reproductive biology, particularly for assessing the follicular microenvironment.