Detection of tumor necrosis factor-alpha cytokine from the blood serum of a rat infected with Pb18 by a gold nanohole array-based plasmonic biosensor

Tumor necrosis factor-alpha (TNF-alpha) is a signaling protein of inflammatory processes. TNF-alpha overexpression triggers inflammatory processes related to various diseases such as rheumatoid arthritis, Crohn's disease, Chagas, and others. For this reason, the TNF-alpha has been used as an important biological biomarker for prognosis, understanding, and disease treatment. Surface plasmon resonance (SPR)-based biosensors are a good alternative for TNF-alpha detection because they are more sensitive than other techniques and have the ability to be developed miniaturized systems. Then we developed a nanohole array on gold nanofilm-based SPR biosensor for TNF-alpha detection. A biological biorecognition system (cysteamine/biotin/streptavidin/TNF-alpha antibody) was formed and TNF-alpha antigen was detected by transmitted light intensity monitoring. TNF-alpha antigen at 17 pg mL(-1) was detected from fungus Paracoccidioides brasiliensis-infected rat blood serum. This concentration is far below those found in similar studies in the literature. This plasmonic device opens new opportunities for TNF-alpha detection. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)