Chiral MoSe 2 Nanoparticles for Ultrasensitive Monitoring of Reactive Oxygen Species In Vivo.

Reactive oxygen species (ROS) are involved in neurodegenerative diseases, cancer, and acute hepatitis, and the early diagnosis of these diseases by quantification of ROS is critical for the curable treatment of patients. Here, a novel probe was developed based on chiral molybdenum diselenide (MoSe 2 ) nanoparticles (NPs) modified by the fluorescence molecule, cyanine 3 (Cy3). Chiral MoSe 2 NPs showed intensive circular dichroism (CD) signals at 390 nm and 550 nm, whereas the fluorescence signal of Cy3 at 560 nm was quenched by MoSe 2 NPs. With the presence of ROS, the novel probe reacted with ROS and then oxidated rapidly, resulting in decreased CD signals and the recovery of Cy3 fluorescence signals. With the help of ROS-related CD and fluorescent dual-mode signals, the limit of detection (LOD) of CD signals and fluorescence signals in living cells was 0.0093 nmol/10 6 cells and 0.024 nmol/10 6 cells, respectively. The high selectivity and sensitivity to ROS in complex biological environments was attributed to the Mo 4+ and Se 2- oxidation reaction on the surface of the NPs. Furthermore, chiral MoSe 2 NPs was able to monitor the levels of ROS in vivo by fluorescence signals. Collectively, this strategy offers a new approach for ROS detection and has the potential to inspire others to explore chiral nanomaterials as potential biosensors to investigate biological events. This article is protected by copyright. All rights reserved.