Novel chemiluminescent nanosystem for highly sensitive detection of hydrogen peroxide in vivo

The overproduction of hydrogen peroxide (H2O2) is closely associated with the progression of various diseases, and thus, it is an important diagnostic marker for in vivo molecular imaging. Although chemiluminescence (CL) imaging with L-012 as a CL agent has been employed to detect H2O2, the low reactivity of H2O2 with L-012 and the short CL emission time of L-012 limit its in vivo H2O2 detection applications. Herein, a novel Co2+-doped L-012/magnesium peroxide-based CL nanosystem (L-012/Co@MgO2) is designed. L-012/Co@MgO2 decomposes in aqueous solutions and releases L-012 and Co2+, and the highly reactive hydroxyl radicals produced by the Co2+-catalysed H2O2 decomposition under an inflammatory environment react with L-012 and yield strong and long-lasting CL emissions. In addition to visually detecting and quantitatively analysing H2O2, the biocompatible L-012/Co@MgO2 CL system against blood cells and major organs can successfully realise H2O2 detection in lipopolysaccharides-induced inflammatory disease models and in vitro screening of the H2O2 scavenging activity of antioxidants. The proposed CL nanosystem has potential applications for the biosensing and bioimaging of H2O2, which is highly produced in various diseases.