Construction of Prussian Blue Fluorescent Nanoprobe for Specific Detection of HClO in Cancer Cells

Hypochlorous acid (HClO) is one of the reactive oxygen species (ROS), taking crucial parts in many physiological and pathological processes.However, excessive HClO causes tissue injuries, atherosclerosis, neurodegeneration diseases, and even cancers.Therefore, real-time detection of HClO in cancer cells is of importance for exploring the effect of HClO in tumor progression or immunotherapy.Quite different from present organic molecular probes, a novel inorganic-based hydrophilic fluorescent nanoprobe was developed by simply integrating fluorescein isothiocyanate (FITC) into hollow mesoporous Prussian Blue nanoparticles (HMPB) in this work.Owing to inner filter effect, fluorescence of FITC within HMPB quenches to some extent, which can be restored via the Fe 2+ -ClO -redox reaction.A typical fluorescence increase of FITC at emission peak of 520 nm can be clearly observed in the presence of HClO in vitro, which exhibits a good linear relationship in the range of 5×10 -6 -50×10 -6 mol/L in HClO detection and its detection limit is calculated to be 2.01×10 -6 mol/L.Furthermore, the cellular experiment demonstrates the specific detection capability of HClO in cancer cells with high sensitivity by the obtained nanoprobe.