An SPR imaging immunosensor for leptin determination in blood plasma

• Published in: Analytical methods 2021-02, Vol.13 (5), p.642-646
• Main Authors: Sankiewicz, Anna, Hermanowicz, Adam, Grycz, Artur, ukaszewski, Zenon, Gorodkiewicz, Ewa
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Biosensing Techniques; Blood plasma; Correlation coefficient; Correlation coefficients; Cysteamine; Energy balance; Enzyme-linked immunosorbent assay; Immunoassay; Immunosensors; Leptin; Malnutrition; Plasma; Rabbits; Surface Plasmon Resonance
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/d0ay02047h

Leptin is a hormone that has a fundamental role in the regulation of feeding and energy balance. A developed specific SPRi immunosensor for leptin may be a new tool for leptin determination in blood plasma. The immunosensor consists of rabbit anti-leptin antibody immobilized on a gold chip via cysteamine linker, using the EDC/NHS protocol. Non-fluidic array SPRi is used for analytical signal formation. Under optimized conditions, the linear response range of the immunosensor covers concentrations from 0.23 to 5 ng mL −1 . The LOD of the immunosensor is 0.07 ng mL −1 , and the LOQ is 0.23 ng mL −1 . The precision of measurement depends on leptin concentration, and is between 9.1% and 2.2%. Recoveries of the leptin spike are between 97% and 110%. The immunosensor and related analytical method were validated by parallel determination of leptin in series of plasma from children suffering from malnutrition and a control group, using Enzyme-Linked Immunosorbent Assay (ELISA) and SPRi. Pearson's correlation coefficient was equal to 0.991. The developed immunosensor and related method are more direct, faster and much simpler than ELISA. The schematic illustration of the biosensor SPRI that is a new promising tool for the determination of leptin concentation. Leptin is a hormone that has a fundamental role in the regulation of feeding and energy balance.