Polymer brush based fluorescent immunosensor for direct monitoring of interleukin-1β in rat blood.

A sandwich immunosensor was successfully developed for monitoring of interleukin-1β (IL-1β) in rat whole blood. The substrate stainless steel (SS) was first coated with a polydopamine layer and subsequently grafted with poly(ethylene glycol) methacrylate brushes, onto which a sandwich immunosensor was modified for detection of IL-1β. The device has been successfully applied for monitoring of IL-1β with a limit of detection of 4.7 pg mL^-1, and a linear detection range of 12.5-200 pg mL^-1. Good specificity and selectivity for monitoring of IL-1β in rat macrophage secretion were achieved. Furthermore, this device was validated by detection of IL-1β in rat whole blood samples with greater concentrations observed in obese rats compared to control, and strong positive correlation between concentrations of IL-1β and blood glucose. These results suggest this device is feasible for direct detection of target analytes in biological samples.