Recent progress of nanomaterials for colorimetric and fluorescence sensing of reactive oxygen species in biological and environmental samples

Incomplete reduction of oxygen produces reactive oxygen species (ROS) or intermediates. Hydrogen peroxide (H2O2), superoxide (O2•−), hydroxyl radical (•OH), and hypochlorite (ClO-) are examples of ROS. Peroxynitrite (ONOO−) belongs to reactive nitrogen species. Recent studies are evidenced that they play crucial roles in cell signaling and tissue homeostasis. Further, ROS are recognized as oxidizing chemical species for various biochemical pathways (oxidative stress and damage of organisms) and as scavengers for various environmental applications. Herein, the recent progress of nanomaterials as optical sensors for colorimetric and fluorescence sensing of reactive oxygen species is discussed. This review also provides the analytical features of nanomaterials-based colorimetric and fluorescent sensors for sensing of ROS in real samples (biological and environmental samples). Additionally, the future prospects of nanomaterials-based colorimetric and fluorescent sensors for the detection of ROS are discussed.