The afterglow photosynthetic luminescence

Abstract

The afterglow (AG) photosynthetic luminescence is a long‐lived chlorophyll fluorescence emitted from PSII after the illumination of photosynthetic materials by FR or white light and placed in darkness. The AG emission corresponds to the fraction of PSII centers in the S2/3QB non‐radiative state immediately after pre‐illumination, in which the arrival of an electron transferred from stroma along cyclic/chlororespiratory pathway(s) produces the S2/3QB− radiative state that emits luminescence. This emission can be optimally recorded by a linear temperature gradient as sharp thermoluminescence (TL) band peaking at about 45°C. The AG emission recorded by TL technique has been proposed as a simple non‐invasive tool to investigate the chloroplast energetic state and some of its metabolism processes as cyclic transport of electrons around PSI, chlororespiration or photorespiration. On the other hand, this emission has demonstrated to be a useful probe to study the effect of various stress conditions in photosynthetic materials.

Iron Deficiency Promotes the Lack of Photosynthetic Cytochrome c550 and Affects the Binding of the Luminal Extrinsic Subunits to Photosystem II in the Diatom Phaeodactylum tricornutum

“…The effect of iron deficiency on the ET PSII activity of P. tricornutum cells was further investigated using the standard thermoluminescence (TL) technique ( Figure 2 ) [ 9 , 10 , 34 ]. Excitation of iron-deficient P. tricornutum WT cells with two flashes at 1 °C induced the appearance of typical TL glow curves, or the so-called B band, but with a significant decrease in the total signal intensity compared with iron-replete conditions ( Figure 2 and Table 1 ) [ 9 ].…”

“…The deconvolution analysis of these emission curves enabled two components to be obtained, with t max values of 16 and 29 °C, respectively, under iron-replete conditions (not shown). These components can be assigned to the well-known B1 and B2 TL bands, originating from the recombination reactions of S 3 Q B − and S 2 Q B − charge pairs, respectively [ 34 , 35 ]. The amplitude of the TL signal is thus related to the overall PSII activity from the water-splitting system to the final quinone acceptor [ 13 , 36 ].…”

Activatable Probes for Ratiometric Imaging of Endogenous BiomarkersIn Vivo

“…Afterglow luminescence has great potential for in vivo imaging as it occurs after the removal of light irradiation and eliminates the need for light excitation, circumventing the issue of tissue autofluorescence. − Zhang et al designed a series of afterglow resonance energy transfer (ARET) based ratiometric probes (RAN) by integrating responsive molecules (NO-responsive NRM, ONOO – -responsive ORM, or pH-responsive PRM), surfactants (F127), afterglow substrates (MEHPPV), and an afterglow initiator (AI, including TPP or BDP) through the self-assembly method (Figure a and b) . Harnessing an AI that can produce 1 O 2 initiates the afterglow (AF1) of an energy donor (MEHPPV) by generating a lively intermediate (PPV dioxetane), which successively transmits the afterglow energy to the energy acceptor (responsive molecules) with a longer emission wavelength (AF2) via an ARET process.…”

Research progress on near-infrared long persistent phosphor materials in biomedical applications

“…LPPs are a class of thermoluminescent materials that emit light at room temperature, which belongs to the electron capture material. 27 The luminescence phenomenon in the electron-trapping materials is formed by the trap-level structure in the materials, such as some inorganic metal oxides, organic composites, inorganic-organic hybrids, and other LPPs. However, owing to the limited availability of analytical techniques and the complexity of the energy-level structure, there is no clear unified mechanistic model for the luminescence mechanism of this material.…”