Core–Shell Poly (Ionic Liquid)@Mesoporous Silica Chemiluminescent Nanoprobes for Sensitive Intracellular Hydrogen Peroxide Imaging

Despite significant developments in spatial distribution imaging of H2O2 as one the most important nonradical reactive oxygen species, novel background-free, highly sensitive, and selective probes that allow intracellular sensing are still imperative. This is mainly because the fluorescent probes usually suffer some drawbacks such as, fluorescence bleaching and requirement of bulky light sources. In this study, the rational design and fabrication of a nonenzymatic nanoprobe (c-PIL@mSiO(2)) with dramatically improved sensitivity for chemiluminescent (CL) imaging of intracellular and in vivo H2O2 at nano molar level is presented. The limit of detection is lower than the endogenous H2O2 concentration, and is significantly better than that of some recently reported fluorescent and CL probes. Structurally, the nanoprobe is composed of a unique amphiphilic poly(ionic liquid) core for preserving H2O2 responsive reagents, and a mesoporous silica shell acts as an "exoskeleton" to provide hydrophilic nature. The multiple alternating hydrophobic and hydrophilic nanodomains of the poly(ionic liquid) core increase mass transfer dynamics, which increase the sensitivity of H2O2 imaging. RAW264.7 macrophages and mice models of inflammations experiment show that the c-PIL@mSiO(2) is capable of imaging H2O2 intracellular and in vivo. This probe for the first time achieves CL detection of endogenous intracellular H2O2 without disruption of cells.