Detection of erythropoietin in blood plasma through an SPRi-based biosensor

A new analytical method based on an SPRi biosensor has been established to determine erythropoietin (EPO) in biological fluids. This protein is involved in the growth of erythroid precursor cells and acts as a therapeutic agent in several diseases. It also appears to have increased biological activity in patients with Alzheimer's disease (AD). A validation process was carried out to assess the optimal ligand-antibody concentration by plotting a calibration curve of EPO. The low limit of detection (LOD) and limit of quantitation (LOQ) values indicate that the developed method can detect very low concentrations in the order of pg/mL. The LOD for EPO was 0.03 pg/mL. The LOQ was 0.10 pg/mL. In addition, determining the appropriate validation parameters confirmed that the designed biosensor has high precision, accuracy, and sensitivity. To prove the usefulness of the biosensor in practice, determinations were performed on blood plasma samples from a control group and a study group consisting of patients with AD. The preliminary results indicate that this biosensor can detect EPO in plasma samples. Confirmation that patients with AD have higher levels of EPO will require the analysis of a more significant number of samples. However, the constructed biosensor is characterized by its simplicity and rapidity of measurement, and the method does not require any special sample preparation.