Two Biosensors for the Determination of Interleukin-6 in Blood Plasma by Array SPRi

• Published in: Biosensors
• Main Authors: Beata Szymanska, Zenon Lukaszewski, Lukasz Oldak, Beata Zelazowska-Rutkowska, Kinga Hermanowicz-Szamatowicz, Ewa Gorodkiewicz
• Format: Article
• Language: English
• Published: MDPI AG 2022-06-01
• Subjects: interleukin-6; array SPRi; cancer biomarkers; ovarian cancer; blood plasma
• Online Access: https://www.mdpi.com/2079-6374/12/6/412

Interleukin-6 (IL-6) is a biomarker of inflammation, the advanced stage of COVID-19, and several cancers, including ovarian cancer. Two biosensors for the determination of IL-6 in blood plasma by array SPRi have been developed. One of these biosensors consists of the mouse monoclonal anti-IL-6 antibody as the receptor immobilized via the cysteamine linker. The second contains galiellalactone as the receptor, being an inhibitor specific for IL-6, immobilized via octadecanethiol (ODM) as the linker. Both biosensors are specific for IL-6. The biosensor with the antibody as the receptor gives a linear analytical response between 3 (LOQ) and 20 pg mL⁻¹ and has a precision between 8% and 9.8% and recovery between 97% and 107%, depending on the IL-6 concentration. The biosensor with galiellalactone as the receptor gives a linear analytical response between 1.1 (LOQ) and 20 pg mL⁻¹, and has a precision between 3.5% and 9.3% and recovery between 101% and 105%, depending on IL-6 concentration. Both biosensors were validated. Changes in IL-6 concentration in blood plasma before and after resection of ovarian tumor and endometrial cyst, as determined by the two developed biosensors, are given as an example of a real clinical application.