Photoelectrochemical immunoassay for human interleukin 6 based on the use of perovskite-type LaFeO nanoparticles on fluorine-doped tin oxide glass.

A film of perovskite-type LaFeO nanoparticles (NPs) was deposited on fluorine-doped tin oxide (FTO) conducting glass via dipping-lifting and calcination. Scanning electron microscopy shows that the NPs are evenly distributed on the surface of the glass. The modified glass was further coated with antibody against human interleukin 6 (IL-6) to result in a photoelectrochemical immunosensor for IL-6. The well-established photoelectrochemical immunoassay has a linear current response in the range of 0.1 pg·mL to 0.1 μg·mL and a detection limit as low as 33 fg·mL. Graphical abstract Schematic of a novel photoelectochemical immunoassay for the measurement of IL-6 based on perovskite-type LaFeO3 nanoparticles. The immunoassay had a higher sensitivity and may also be applied to other bioanalysis and environment monitoring.