Polymer-based room-temperature phosphorescence (RTP) materials with high flexibility and large-area producibility are highly promising for applications in organic electronics. However, achieving such photophysical materials is challenging because of difficulties in populating and stabilizing susceptible triplet excited states at room temperature. Herein large-area, flexible, transparent, and long-lived RTP systems prepared by doping rationally selected organic chromophores in a poly­(vinyl alcohol) (PVA) matrix were realized through a hydrogen-bonding and coassembly strategy. In particular, the 3,6-diphenyl-9H-carbazole (DPCz)-doped PVA film shows long-lived phosphorescence emission (up to 2044.86 ms) and a remarkable duration of afterglow (over 20 s) under ambient conditions. Meanwhile, the 7H-dibenzo­[c,g]­carbazole (DBCz)-doped PVA film exhibits high absolute luminance of 158.4 mcd m2 after the ultraviolet excitation source is removed. The RTP results not only from suppressing the nonradiative decay by abundant hydrogen-bonding interactions in the PVA matrix but also from minimizing the energy gap (ΔE ST) between the singlet state and the triplet state through the coassembly effect. On account of the outstanding mechanical properties and the afterglow performance of these RTP materials, they were applied in the fabrication of flexible 3D objects with repeatable folding and curling properties. Importantly, the multichannel afterglow light-emitting diode arrays were established under ambient conditions. The present long-lived phosphorescent systems demonstrate a bright opportunity for the production of large-area, flexible, and transparent emitting materials.

BackgroundMushroom showed pellet, clump and/or filamentous mycelial morphologies during submerged fermentation. Addition of microparticles including Talc (magnesium silicate), aluminum oxide and titanium oxide could control mycelial morphologies to improve mycelia growth and secondary metabolites production. Here, effect of microparticle Talc (45 μm) addition on the mycelial morphology, fermentation performance, monosaccharide compositions of polysaccharides and enzymes activities associated with polysaccharide synthesis in G. frondosa was well investigated to find a clue of the relationship between polysaccharide biosynthesis and morphological changes.ResultsAddition of Talc decreased the diameter of the pellets and increased the percentage of S-fraction mycelia. Talc gave the maximum mycelial biomass of 19.25 g/L and exo-polysaccharide of 3.12 g/L at 6.0 g/L of Talc, and mycelial polysaccharide of 0.24 g/g at 3.0 g/L of Talc. Talc altered the monosaccharide compositions/percentages in G. frondosa mycelial polysaccharide with highest mannose percentage of 62.76 % and lowest glucose percentage of 15.22 % followed with the corresponding changes of polysaccharide-synthesis associated enzymes including lowest UDP-glucose pyrophosphorylase (UGP) activity of 91.18 mU/mg and highest UDP-glucose dehydrogenase (UGDG) and GDP-mannose pyrophosphorylase (GMPPB) activities of 81.45 mU/mg and 93.15 mU/mg.ConclusionOur findings revealed that the presence of Talc significantly changed the polysaccharide production and sugar compositions/percentages in mycelial and exo-polysaccharides by affecting mycelial morphology and polysaccharide-biosynthesis related enzymes activities of G. frondosa.

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Long‐lived room temperature phosphorescence (RTP) materials are widely utilized in the field of biological and chemical sensing, due to their unique characteristics of long‐lived luminescence and no background autofluorescence. However, the realization of full‐color RTP in aqueous solution still remains a great challenge. Herein, a feasible strategy for achieving high stability and full‐color RTP of carbon dots (CDs)‐based composite materials in aqueous environment is reported by constructing a rigid hydrogen bonds’ network. The obtained m,p‐CDs@CA composite materials exhibit deep‐blue RTP with phosphorescence quantum yield of 23.2% and lifetime of 1.74 s, and the afterglow can last for over 12 s. More importantly, the m,p‐CDs@CA composite materials are desirable in the detection of biomarkers, because of excellent stability, dispersion, and long‐lived RTP properties. The m,p‐CDs@CA suspension also displays excellent sensitivity, and a limitation of detection as low as 5.61 and 550 nm for biomarkers 5‐hydroxyindole‐3‐acetic acid (HIAA) and serotonin (5‐hydroxytryptamine, HT), respectively. Meanwhile, the sensing performance exhibits excellent selectivity even in the presence of other competitive species in blood plasma and urine. With superior selectivity, the long‐lived phosphorescence probe based on m,p‐CDs@CA suspension can be as an effective biomarker for carcinoid identification, which has potential application in clinical analysis.