singlet

1,3-Diphenylisobenzofuran (DPBF) is a fluorescent probe. It possesses a highly specific reactivity towards singlet oxygen forming an endoperoxide which decomposes to give 1,2-dibenzoylbenzene. 1,3-Diphenylisobenzofuran can detect the generation of reactive oxygen species (ROS).

TMB(dihydrochloride x.hydrate) is the dihydrochloride salt and hydrate form of TMB. It is a non-toxic and non-mutagenic colorless dye used as a chromogenic agent in horseradish peroxidase-based assay systems. This compound also serves as a photoacoustic probe for reactive oxygen and nitrogen species (ROS/RNS), reacting with hypochlorite, hydrogen peroxide, singlet oxygen, and nitrogen dioxide to produce a blue oxidized product. Additionally, TMB(dihydrochloride x.hydrate) can detect singlet oxygen produced by the outer membrane of Escherichia coli ATCC 25922.

Palladium meso-tetra(pentafluorophenyl)porphyrin is a high-performance oxygen-sensing phosphorescent probe. It features long-lived phosphorescence and efficient oxygen quenching, used for cell respiration monitoring and hypoxia imaging.

Thio-acridone is an atomic photosensitizer (HAF-PSs) that, when excited by visible light at 470 nm, forms a long-lived triplet state, ultimately generating singlet oxygen to disrupt the structure and function of target cells (e.g., cancer cells). Thio-acridone shows potential for use in cancer research.

Di-4-ANEPPS is a fast-response, electrochromic membrane potential fluorescent probe based on a naphthylstyrylpyridinium structure. Its response mechanism involves membrane potential changes causing intramolecular charge transfer, leading to a blue shift in the excitation spectrum. It enables real-time detection of millisecond-scale transient membrane potential changes in excitable cells (e.g., neurons and cardiomyocytes) through ratiometric imaging. Di-4-ANEPPS is non-fluorescent before incorporating into lipid membranes; after incorporation, excitation/emission peaks are approximately in the 465-482 nm/635-686 nm range. Besides being widely used in cardiac electrophysiology and drug cardiac toxicity assessment, it is also a target molecule in studies of singlet oxygen-mediated photooxidative damage at membrane interfaces. Note that Di-4-ANEPPS itself may cause non-reversible interference with cardiac conduction parameters (e.g., heart rate, conduction velocity) at high concentrations or under prolonged illumination and can inhibit sodium current.

TPP-Ce6 is a mitochondria-targeting photosensitizer formed by the ester linkage of chlorin e6 (Ce6) with triphenylphosphine (TPP). Upon light exposure, TPP-Ce6 generates reactive oxygen species (ROS), particularly singlet oxygen, which induce oxidative stress, leading to mitochondrial dysfunction and apoptosis (cellular apoptosis). This compound is useful for research on mitochondrial roles in apoptosis, energy metabolism, and cancer treatment.