Electrochemical IFN-γ immunosensor based on a nanocomposite of gold nanorods and reduced graphene oxide.

Interferon-γ (IFN-γ) is a vital part of the immune system, and a critical biomarker determining the progression of several diseases, like tuberculosis, HIV, and multiple sclerosis. This work presents an electrochemical immunosensor for detecting IFN-γ based on an indium–tin oxide electrode modified with a nanocomposite of gold nanorods and reduced graphene oxide (AuNR-rGO). The antibodies are immobilized on the modified electrode. Subsequent addition of analyte proteins causes a drop in the peak current in the differential pulse voltammetry (DPV) since the proteins hinder electron transfer. The DPV peak current values are proportional to logarithmic IFN-γ concentrations in the dynamic range of 5–1000 pg/mL with a detection limit of 2.5 pg/mL. In addition, this immunosensor shows high specificity to IFN-γ in the presence of competent inflammatory proteins (IL-4 and TNF-α) in phosphate-buffered saline and human blood samples. Our results demonstrate the potential of AuNR-rGO nanocomposite as an effective electrode material for improved sensor performance, providing a simple, sensitive, and specific detection of IFN-γ. [ABSTRACT FROM AUTHOR]