Singlet Oxygen Generation with Chemical Excitation of an Erythrosine–Luminol Conjugate

Abstract

Chemical generation of singlet oxygen under biologically relevant conditions is very important, considering the role played by singlet oxygen in cancer therapeutics. We now demonstrate that a luminol derivative can be chemically excited and transfer the excitation energy to the covalently attached photosensitizer derived from erythrosin. A photosensitizer module, when excited in this manner, can generate singlet oxygen in solution. As hydrogen peroxide is present in a relatively high concentration in cancer cells, singlet oxygen generation through chemical excitation may evolve into an important therapeutic approach.

Molecular Basis of the Chemiluminescence Mechanism of Luminol

“…One of the most important and popular chemiluminescent systems is the luminol molecule (5‐amino‐2,3‐dihydrophthalazine‐1,4‐dione, LH 2 ), which is widely used in forensic science to detect traces of blood, since it is catalyzed by iron of the hemoglobin protein . First discovered in 1928 by Albrecht, the chemiluminescence of LH 2 has since been the topic of many fundamental studies and the development of commercial analytical assay kits and challenging therapeutic procedures to treat cancers in deep tissues . It is worth mentioning in this last context, for example, investment from hospitals and research groups to find noninvasive methods to treat inaccessible tumors, for example, the glioblastoma multiforme brain tumor, by means of mitochondria‐targeting LH 2 systems .…”

“…[1,2] First discoveredi n1 928 by Albrecht, [3] the chemiluminescence of LH 2 has since been the topic of many fundamentals tudies and the development of commercial analytical assay kits [4][5][6][7][8][9] and challenging therapeutic procedures to treat cancers in deep tissues. [10][11][12][13][14] It is worth mentioning in this last context, for example, investment from hospitals and research groups to find noninvasive methodst ot reat inaccessible tumors, for example, the glioblastoma multiformeb rain tumor,b ym eans of mitochondria-targeting LH 2 systems. [10] To assist in such developments,i ti sc rucial to have ad etailed comprehension of the chemiluminescence mechanism and key electronic structure factors in the chemiexcitation phenomenon.…”

Dual-purpose zinc and silicon complexes of 1,2,3-triazole group substituted phthalocyanine photosensitizers: synthesis and evaluation of photophysical, singlet oxygen generation, electrochemical and photovoltaic properties

“…A promising photosensitizer should have the ability to perform an efficient intersection transition so that it can transfer energy to underground-state molecular oxygen. 7,8 Phthalocyanines are the leading photosensitizers with this property. The rst step in PDT treatments is to synthesize suitable photosensitizers and to evaluate the photophysical and photochemical properties of this photosensitizers and to test its usability for the PDT.…”

Photodynamic Therapy of Cancers With Internal Light Sources: Chemiluminescence, Bioluminescence, and Cerenkov Radiation

“…Covalent attachment of luminol to the photosensitizer into a single molecule is an additional strategy for constructing a CL-PDT system through the direct energy transfer from luminol to the photosensitizer. Yesilgul et al ( 2017 ) designed a modular unimolecular erythrosine–luminol which can produce singlet oxygen in the presence of Cu 2+ and hydrogen peroxide. Xu et al ( 2019 ) synthesized a Ce6–luminol–PEG (CLP) conjugate which can self-assemble into core–shell nanoparticles.…”