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

A sandwich immunosensor was successfully developed for monitoring of interleukin-1 beta (IL-1 beta) 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-1 beta. The device has been successfully applied for monitoring of IL-1 beta 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-1 beta in rat macrophage secretion were achieved. Furthermore, this device was validated by detection of IL-1 beta in rat whole blood samples with greater concentrations observed in obese rats compared to control, and strong positive correlation between concentrations of IL-1 beta and blood glucose. These results suggest this device is feasible for direct detection of target analytes in biological samples.