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Although protein‐polymer phosphors are an emerging photon‐management filter concept for hybrid light‐emitting diodes, deep‐red‐emitting devices based on archetypal fluorescent proteins (FPs; mCherry) are still poorly performing with lifetimes <50 h under high photon‐flux excitation and ambient conditions. Here, the challenge is two‐fold: i) understanding the deactivation mechanism of red‐emitting FP‐polymer coatings and, in turn, ii) identifying the best polymer design for highly stable devices. This study first provides comprehensive photophysical/thermal/structural studies and device degradation (ambient/inert) analysis, revealing the presence of photo‐induced cis–trans isomerization and the effect of oxygen and water on the deactivation of mCherry in reference polymer coatings. Based on these findings, a new bio‐phosphor configuration using polyvinyl alcohol derivatives, in which crystallinity and amount of trapped water (stiffness and oxygen/moisture barriers) are easily controlled by the hydroxylation degree, is successfully achieved. Compared to the prior art, these devices significantly outperform the reference stability (>50‐fold enhancement), showing a brightness loss of <5% over the first 2000 h and a final device lifetime of 2600 h. Hence, this study describes a unique rationale toward designing polymers to stabilize FPs for lighting, overpassing stability frontiers in deep‐red hybrid light‐emitting diodes (HLEDs) going from hours to months. [ABSTRACT FROM AUTHOR]

Biophosphors with fluorescent proteins (FPs) are promising candidates to replace rare‐earth color down‐converting filters for white light‐emitting diodes (LEDs). There is, however, a lack of deep‐red FPs meeting high photostabilities, photoluminescence quantum yields (ϕ), and throughput expression yields. Herein, a new approach for the design of highly emissive and stable deep‐red biophosphors combining an artificial FP (Lactococcal multidrug resistance Regulator (LmrR) as protein host and an archetypal red‐emitting squaraine (S) as guest) with a polymer network is demonstrated toward high performing deep‐red biohybrid LEDs (Bio‐HLEDs). At first, the best protein pocket (aromaticity, polarity, charge, etc.) to stabilize S in water is determined using four LmrR variants (position 96 with tryptophan, histidine, phenylalanine, and alanine). Computational and time‐resolved spectroscopic findings suggest that the tryptophan is instrumental toward achieving artificial red‐emitting FPs with ϕ > 50% stable over weeks. These features are further enhanced in the polymer coating (ϕ > 65% stable over months) without affecting emission color. Finally, deep‐red Bio‐HLEDs are fabricated featuring external quantum efficiencies of 7% and stabilities of ≈800 h. This represents threefold enhancement compared to reference devices with S‐polymer color filters. Overall, this work highlights a new design for highly emissive deep‐red biophosphors, achieving record performance in deep‐red protein‐LEDs. [ABSTRACT FROM AUTHOR]

Lighting systems with circularly polarized luminescence (CPL) are an emerging field with high hopes in, for example, neural cell circuits and encoding applications. The major challenges that forfeits their real‐world application are i) the design of chiroptical materials (CMs) with high CPL brightness (BCPL; today's record is Eu‐based compounds with average 287 M−1cm−1, while 90% of other CMs show <150 M−1cm−1 in solution) and ii) how to keep CPL response in films/coatings of technological relevance. Since natural evolution is driven by chiral selectivity at the supramolecular level, fluorescent proteins (FPs) are ideal candidates to provide large BCPL spanning visible and near‐infrared regions. This hypothesis is confirmed for all the known FP classes, demonstrating high emission intensities (photoluminescence quantum yields (ϕ) up to 76%) and record average BCPL of |200| M−1cm−1 (solution). What is more, the CPL response is also kept in polymer coatings. It is rationalized that structural factors (chromophore rigidity, surrounding amino acids, supramolecular packaging, and exciton coupling) hold a significant influence, regardless of the ϕ values. Finally, proof‐of‐concept CPL‐encoded signals in monochromatic/white hybrid light‐emitting diodes with FP‐polymer filters show exceptional stabilities. Overall, this work stands out FPs toward a new CM family, in general, and biogenic CPL‐encoded lighting systems, in particular. [ABSTRACT FROM AUTHOR]

Stable and efficient high‐power biohybrid light‐emitting diodes (Bio‐HLEDs) using fluorescent proteins (FPs) in photon downconverting filters have not been achieved yet, reaching best efficiencies of 130 lm W−1 stable for >5 h. This is related to the rise of the device temperature (70–80 °C) caused by FP‐motion and quick heat‐transmission in water‐based filters, they lead to a strong thermal emission quenching followed by the quick chromophore deactivation via photoinduced H‐transfer. To tackle both issues at once, this work shows an elegant concept of a new FP‐based nanoparticle, in which the FP core is shielded by a SiO2‐shell (FP@SiO2) with no loss of the photoluminescence figures‐of‐merit over years in foreign environments: dry powder at 25 °C (ambient) or constant 50 °C, as well as suspensions in organic solvents. This enables the preparation of water‐free photon downconverting coatings with FP@SiO2, realizing on‐chip high‐power Bio‐HLEDs with 100 lm W−1 stable for >120 h. Both thermal emission quenching and H‐transfer deactivation are suppressed, since the device temperature holds <40 °C and remote high‐power Bio‐HLEDs exhibit final stabilities of 130 days compared to reference devices with water‐based FP@SiO2 (83 days) and FP‐polymer coatings (>100 h). Hence, FP@SiO2 is a new paradigm toward water‐free zero‐thermal‐quenching biophosphors for first‐class high‐power Bio‐HLEDs. [ABSTRACT FROM AUTHOR]

This work describes the first use of blue‐emitting boron‐ and nitrogen‐doped carbon dots (BN‐CDs), rationalizing their photoluminescence behavior in solution and ion‐based thin‐films to prepare white light‐emitting electrochemical cells (LECs). In detail, a cost‐effective and scalable water‐based microwave‐assisted synthesis procedure is set for BN‐CDs featuring an amorphous carbon‐core doped with N and B. While they show a bright (photoluminescence quantum yield of 42%) and excitation‐independent blue‐emission (440 nm) in solution related to emitting n−π* surface states, they are not emissive in thin‐films due to aggregation‐induced quenching. Upon fine‐tuning the film composition (ion‐based host), an excitation dependent emission covering the whole visible range is noted caused by interaction of the ion electrolyte with the peripheral functionalization of the BN‐CDs. Moreover, the efficient energy transfer from the host to the BN‐CDs emitting species enabled good performing LECs with white emission (x/y CIE coordinates of 0.30/0.35, correlated color temperature of 6795 K, color rendering index of 87) and maximum luminance of 40 cd m−2, and stabilities of a few hours. This represents a significant improvement compared to the prior‐art monochromatic CD‐based LECs with similar brightness levels, but stabilities of <1 min. [ABSTRACT FROM AUTHOR]

Accomplishing sustainability in optoelectronics, in general, and photovoltaics (PV), in particular, represents a crucial milestone in green photonics. Third generation PV technologies, such as organic solar cells (OSCs), perovskite solar cells (PSCs), and dye‐sensitized solar cells (DSSCs) have reached a mature age and are slowly making their way in the market as complementary devices to the first generation solar cells. For example, they are well suited for high‐end smart applications, like flexible and wearable devices, fully transparent solar cells and windows, and biocompatible devices for medical applications. In this context, major efforts have been conducted to realize easy‐to‐do and low‐cost recycling devices without losing performance level. This has fueled a strong cooperation between engineering, biology, chemistry, and physics fields to discover new strategies for cost‐effectiveness preparation and implementation of bio‐derived materials in highly performing PVs. The recent efforts of these groups are honored here, providing a general overview on bio‐derived materials suitable for PV applications as well as an in‐depth revision of the most relevant and recent advances obtained by merging biology and third generation PV technologies. [ABSTRACT FROM AUTHOR]

Stable/efficient low‐energy emitters for photon down‐conversion in bio‐hybrid light‐emitting diodes (Bio‐HLEDs) are still challenging, as the archetypal fluorescent protein (FP) mCherry has led to the best deep‐red Bio‐HLEDs with poor stabilities: 3 h (on‐chip)/160 h (remote). Capitalizing on the excellent refolding under temperature/pH/chemical stress, high brightness, and high compatibility with polysaccharides of phycobiliproteins (smURFP), first‐class low‐energy emitting Bio‐HLEDs are achieved. They outperform those with mCherry regardless of using reference polyethylene oxide (on‐chip: 24 h vs. 3 h) and new biopolymer hydroxypropyl cellulose (HPC; on‐chip: 44 h vs. 3 h) coatings. Fine optimization of smURFP‐HPC‐coatings leads to stable record devices (on‐chip: 2600 h/108 days) compared to champion devices with perylene diimides (on‐chip: <700 h) and artificial FPs (on‐chip: 35 h). Finally, spectroscopy/computational/thermal assays confirm that device degradation is related to the photo‐induced reduction of biliverdin to bilirubin. Overall, this study pinpoints a new family of biogenic emitters toward superior protein‐based lighting. [ABSTRACT FROM AUTHOR]

Merging Biology and Photovoltaics: How Nature Helps Sun-Catching (Adv. Keywords: bio-based energy devices; bio-derived materials; green photonics; photovoltaics; sustainable optoelectronics EN bio-based energy devices bio-derived materials green photonics photovoltaics sustainable optoelectronics 1 1 1 11/23/21 20211118 NES 211118 B Bio-Derived Materials b In article number 2100520, Rubén D. Costa and co-workers provided an extensive overview of emerging bio-derived materials suitable for organic solar cells, dye-sensitized solar cells and perovskite solar cells. Bio-based energy devices, bio-derived materials, green photonics, photovoltaics, sustainable optoelectronics. [Extracted from the article]

Alzheimer’s disease (AD) is a neurodegenerative disease affecting over 20 million people worldwide, mainly adult subjects in advanced age. Over 240 different fully penetrant autosomal dominant mutations in 532 families around the world have been described in three genes [i.e., amyloid precursor protein ( APP ), and presenilins ( PSEN1 and PSEN2 )] causing 50% of all Familial AD. We report a new mutation (p.Ile408Thr, c. 1223T > C) in the PSEN1 gene in one autosomal dominant Late Onset AD patient. The genetic variation occurred in a conserved domain of the protein and was present in the proband and in the younger sister who is likely to be prodromal AD. Thus, we suggest that this variant will have probably a pathogenic effect, hypothesizing a possible key role of this new mutation in the pathogenesis of Alzheimer’s disease for this family. [ABSTRACT FROM AUTHOR]