Silver molybdate nanoparticles based immunosensor for the non-invasive detection of Interleukin-8 biomarker

In this study, we report the silver molybdate nanoparticles (β-Ag₂MoO₄ NPs) based non-invasive and sensitive electrochemical immunosensor for label-free detection of Interleukin-8 (IL-8) biomarker. The X-ray diffraction and Raman spectroscopy studies confirm the cubic spinel structures of β-Ag₂MoO₄ NPs. High-resolution transmission electron microscopy study depicted average size of β-Ag₂MoO₄ NPs as 27.15 nm. The cleaned indium tin oxide coated glass substrates were coated with spin-coated thin films of Ag₂MoO₄ NPs. These electrodes used for covalently immobilization of antibodies specific to IL-8 (Anti-IL-8) using EDC-NHS chemistry and unbound activated sites blocked by bovine serum albumin. Electrochemical response was obtained in the range of 1 fg mL^-1 to 40 ng mL^-1 and the sensitivity was found to be 7.03 μA ng^-1mL cm^-2 with LOD of 90 pg mL^-1. Spiked samples prepared by human saliva were tested and found efficient detection with this immunoelectrode.