Metal-enhanced fluorescence (MEF) represents a captivating phenomenon that transpires when fluorophores are situated in close vicinity to the surface of metallic nanostructures, leading to a nuanced augmentation of their fluorescent characteristics. Given its efficacy in enhancing excitation rates, quantum yield, and photostability, MEF has firmly established itself as a highly valuable tool for augmenting biosensor sensitivity, bioimaging clarity, and intensifying therapeutic responses. Notably, plasmonic gold nanostructures, inherently advantageous for MEF, have been widely utilized in signal amplification, fluorescent labeling, and theranostics. In this endeavor, we undertake a comprehensive examination of MEF-enabled gold nanostructures, meticulously analyzing their fundamental enhancement mechanisms, crucial influencing factors, and diverse modes of enhancement. Furthermore, we spotlight the exemplary applications of these nanostructures in biosensing, bioimaging, and theranostics, underscoring their revolutionary potential. Ultimately, we offer a glimpse into the future prospects for improvement and the challenges that beset gold-based MEF. Our attention is steadfastly directed toward the essential scientific questions and technical hurdles that remain to be surmounted, inviting readers to partake in an exciting exploration of this dynamic and promising field.

Parathyroid hormone (PTH) is an important factor in maintaining blood calcium levels in the human body. Therefore, monitoring PTH levels is essential for assessing the various diseases progression and managing overall health. In this study, a fluorescence and optical sensor based on an aggregation-induced emissive liquid crystal photopolymer (AIE-LC-Poly) film was established for the qualitative and quantitative detection of PTH. The specific interaction between PTH and anti-PTH on the substrate surface was utilized, and variations in orientation and aggregation state of the fluorescent LCs were evaluated by both optic and fluorescent means. The detection limit for PTH using optical image was above 10 µg/mL, while fluorescence detection achieved a much lower limit of 1 ng/mL. Additionally, the photopolymer further amplified the detection signals by strengthening the AIE effect of the fluorescent LCs in initiate state, and enhancing the disturbance of LCs ordered orientation upon PTH addition. Ultimately, the detection limits for PTH were reduced to 0.01 µg/mL for optical detection and 50 pg/mL for fluorescence detection. The quantitative and sensitive AIE-LC-Poly biosensing technology presented here sets the stage to develop LC-based sensor for biomedical applications without labeling.

Prostate cancer is an epithelial malignancy with a high incidence among elderly men. Photochemistry-based dye photodrugs (known as photosensitizers) offer a promising clinical approach for treating tumors. These agents work by inducing immunogenic cell death (ICD), which activates antitumor immune response. This approach is favored owing to its minimal invasiveness, low toxicity, and high efficiency. However, the immunosuppressive microenvironment of characteristics of “cold” tumors significantly restricts the clinical efficacy of photodrugs. Developing an advanced nanocarrier system to deliver photodrugs and immune agonists for efficient drug delivery to tumor lesion sites and to reshape the immunosuppressive microenvironment is crucial in clinical practice. Therefore, in this study, we designed an integrin-targeted, activatable nano photodrug co-assembly with an immune agonist (RPST@IMQ) for enhancing photoimmunotherapy in prostate cancer via the reprogramming of tumor-associated macrophages. The active-targeted nanosystem enhanced the dosage of photodrug at the lesion site through systemic administration. High doses of glutathione at the tumor site cleaved the disulfide bonds of RPST@IMQ, releasing the photodrug and the immune agonist imiquimod (IMQ). Under photoirradiation, the photodrug generated significant doses of singlet oxygen to eliminate tumor cells, thereby inducing ICD to activate antitumor immune responses. Simultaneously, the released IMQ reprograms immunosuppressive M2-type tumor-associated macrophages (TAMs) in the tumor microenvironment into M1-type TAMs with tumor-killing capabilities, thereby converting “cold” tumors into “hot” tumors. This conversion enhances the therapeutic efficacy against primary and distant tumors in vivo. This study offers new insights into the development of innovative, smart, activatable nano photodrugs to enhance anticancer therapeutic outcomes.

Bacterial infections are one of the greatest threats to wound healing, and microbial resistance has increased the demand for new antimicrobial dressings. Artificial nanozymes possess myriad considerable advantages, including low cost and high activity, for targeted biological treatments. Despite significant efforts made in nanozyme engineering, significant challenge remains that their catalytic performance is far from satisfactory in wound treatment. Herein, based on biowaste valorisation, we propose a sustainable and efficient strategy to synthesize an ultrafine-Mn-loaded (3.0 ± 1 nm) N,O-doped porous nanocarbons (Mn-PNCs) nanozyme via the Mott−Schottky effect. The nanozyme achieves mid-temperature (45.8°C) and superior photothermal conversion efficiency (77.62%), photothermally enhanced peroxidase-like activity that contributes to the effective treatment of methicillin-resistant Staphylococcus aureus-infected wounds. The photo-enzyme platform further reduced the inflammatory response, normalized epidermal tissue regeneration, and accelerated wound healing. Notably, the mechanism demonstrated that this Mott−Schottky catalyst can trigger the rapid transfer of electrons to release reactive oxygen species (ROS) species, as a heterojunction system is strongly capable of changing the electron density within the metal. Under photothermal induction, the Mott–Schottky contact can be used to fabricate other polysaccharide-derived nanozymes in tissue engineering, or on the high-value application of biomass resources.

Control of the dissymmetry of circularly polarized luminescence (CPL) is intriguing and has great potential for applications in the field of optics. The traditional control strategy involves using the opposite enantiomers to achieve reversal of CPL signs. However, regulating CPL reversal by controlling only the transition dipole moments without changing molecular or supramolecular chirality remains a challenge. Herein, we developed a couple of crystal materials based on axially chiral aggregation-induced emission luminogens (AIEgens). These materials exhibit achiral solvent-induced CPL sign inversion with identical helical structures and molecular chirality in their crystalline states. (R)-BPAuCz^T displays (+)-CPL with a dissymmetry factor of luminescence (g_lum) value of +9.81 × 10⁻⁴ (560 nm), while (R)-BPAuCz^C exhibits (−)-CPL with a g_lum value of −1.02 × 10⁻³ (560 nm). Time-dependent density functional theory calculations show that the magnetic and electric transition dipole moments at S₁ → S₀ of the (R)-BPAuCz^C unit cell are considerably influenced by the cocrystallized solvent molecules, revealing a solvent-induced CPL inversion mechanism. The nonbonding interactions between the solvent molecules (i.e., tetrahydrofuran or CDCl₃) and AIEgens in the crystal play a crucial role in the manipulation of the transition dipole moment of these crystal materials. Moreover, microrods of (R)-BPAuCz^T, (R)-BPAuCz^C, and (R)-BPAuCz^DCE exhibit optical waveguide properties with relatively low optical-loss coefficients of 187.3, 567.4, and 65.2 dB/cm, respectively. These findings can help in developing a new strategy toward controlling CPL signals and providing a potential application for future integrated photonic circuits.

Zero-dimensional (0D) hybrid metal halides (HMHs) hold great promise as multifunctional emitters. However, precise functionalization of organic moieties and controlled modulation of self-trapped exciton (STE) emission from inorganic polyhedra remain challenging. This study introduces 0D (PMA)₃InBr₆ (PMA⁺ = C₆H₅CH₂NH₃⁺) as a multifunctional emitter, leveraging pressure-induced structural regulation to control photoluminescence properties. Increasing pressure leads to simultaneous contraction and distortion of InBr₆³⁻ octahedra, shifting the STE emission color from orange to green. At high compression, structural amorphization quenches STE emission, but upon pressure release, a bright cyan emission from the PMA⁺ cation emerges, with intensity approximately 21 times stronger than that of the initial STE emission. The enhanced emission is attributed to altered molecular configurations, disrupted intermolecular contacts, and reduced lattice vibrations, collectively suppressing excimeric coupling and minimizing nonradiative losses in the recovered amorphous phase. Furthermore, emission conversion is also achieved via laser-induced structural amorphization, expanding the potential of (PMA)₃InBr₆ for direct laser writing and sensitive laser detection applications.

Tumor drug resistance has been reported to be associated with drug efflux in tumor cells. Recently, a noninvasive and safe mechanism, sonodynamic therapy (SDT), has been proposed to be an oxidative stress strategy to potentially overcome drug efflux, but with efficacy limitation. Herein, we propose a systematic strategy for optimizing SDT, especially revealing the key role of acoustics parameters acting in SDT efficiency. A doxorubicin (DOX)-loaded sonosensitive micelle (DPM) mediated “sono-force” combination (chemotherapy and sonodynamic) therapy strategy, named DPCSTs, which was designed for amplifying SDT to augment oxidative stress to overcome drug efflux and induce robust long-term inhibition of tumor development by optimized acoustic parameters. The sub-10 nm size DPM enhanced tumor targeting and renal clearance. Meanwhile, another important component, doxorubicin, significantly suppressed residual tumors (78.6%) due to “sono-force” augmented oxidative stress reversing drug efflux, finally leading to long-term tumor development limitation in vivo. It is the first time to propose a systematic strategy for optimizing SDT regimens to overcome resistance, which can synergize with chemotherapy to exert long-term tumor development inhibition. We believe that this work will advance SDT-related research to a new level, and improve our understanding of overcoming resistance of targeted cancer therapy.

Purely organic single-component luminescent materials enabling multi-color photoluminescence are gaining significant interest, given their tunable optical properties, environmental friendliness, and cost-effectiveness. However, realizing multi-color electroluminescence from a single-component emitter for application in organic light-emitting diode (OLED) remains challenging, mainly due to the limitations in achieving distinct excited-state conformations in amorphous or solid states. In this study, we report two novel emitters (Bppy-PTZ and Bpph-PTZ) by incorporating a benzophenone acceptor and phenothiazine donor with pyridyl and phenyl π-bridging spacers. The introduction of a pyridine ring in Bppy-PTZ establishes intramolecular hydrogen bonding, stabilizing the quasi-axial (QA) conformation in the amorphous state, thereby facilitating multi-color and white-light emissions in thin-film and OLED devices. Photophysical and theoretical analyses reveal distinct emission behaviors from QA and quasi-equatorial conformations, with Bppy-PTZ exhibiting enhanced dual-emission and mechanochromic properties. Importantly, by adopting single-component Bppy-PTZ, the fabricated OLEDs realize color-tunable emissions, including blue, yellow, and adjustable white lights, reaching maximum external quantum efficiencies of up to 15.5%. This work provides valuable insights for the development of efficient single-component emitters affording multi-color OLEDs with high performances.

Imaging-guided phototherapy holds promise for precision cancer treatment. However, most photosensitizers have only a singular modality of photodynamic therapy (PDT) or photothermal therapy (PTT), which make their therapeutic efficacy severely limited by the hypoxic and complex tumor microenvironment (TME). In this article, we provide a smart platform design (BOD-D) based on a visualized light-triggered phototherapeutic switch for transforming cancer therapy from near-infrared (NIR)-I imaging-guided PDT to activatable NIR-II-guided PTT while releasing nitric oxide (NO) for gas therapy (GT). BOD-D releases native NIR one-region fluorescence signals in tumors, which is used to direct robust PDT for tumor killing. As PDT is administered, the decreasing oxygen content in TME becomes progressively insufficient to maintain its excellent cell-killing effect. Subsequently, light triggers the dissociation of NO in BOD-D, activating a photothermal agent BOD-T that emits NIR-II fluorescence, for subsequent PTT. Notably, not only the light-mediated therapeutic mechanism can be switched from NIR-I-guided PDT to NIR-II-guided PTT, but also the NO released during this process will be used for GT to sensitize the above PDT and PTT. Our study contributes to the design of intelligent photosensitizers for cascade tumor photoablation.

Luminescent lanthanide cerium(III) compounds have gathered increasing research interest in both inorganic phosphors and functional molecular complexes. Cerium(III) exhibits broad double-peak emission originating from 5d excited state ²D_3/2 to 4f ground states ²F_7/2 and ²F_5/2. It is vital to adjust the bandwidth of the emission for different applications like lighting and display, while no regulation between these two peaks in Ce(III) emitters has been reported hitherto. In this work, novel heavy-atom-induced narrow emission is observed in luminescent Ce(III) complexes by adopting imidodiphosphinate ligand with different chalcogen-coordinating sites from O to S, Se, and Te. Not only a new Ce(III) complex with orange–red emission beyond the traditional emission color regions of Ce(III) was obtained, but also the ratio of the two peaks was systematically tuned to achieve the narrowest emission from Ce(III) with a full width at half maximum of 42 nm. Time-dependent density functional theory calculations ascribe the tuning of emission spectra to centroid shift and simultaneously provide the orbital contribution values of different chalcogen atoms to the emission excited state. By extending the coordination atoms from classic oxygen and nitrogen to heavier and softer elements, these results give new insight into luminescence properties and mechanisms of Ce(III) emission.

Bimetallic nanoparticles (NPs) are recognized as effective catalysts for the nitrate reduction reaction (NO₃^–RR) to produce ammonia (NH₃) due to their multiple active sites and electron redistribution enabled by strong metal–metal interactions. An in-depth analysis of the reaction mechanism is essential for advancing efficient electrocatalysts. In this study, carbon-supported Au₃Cu alloy catalysts (Au₃Cu/CC) were synthesized and applied for the direct reduction of NO₃⁻ to NH₃. The NH₃ generation rate achieved with Au₃Cu/CC was 1719.3 µg h⁻¹ cm⁻², and the Faraday efficiency (FE) of NH₃ was measured at 95.1% under an ultra-low potential of −0.5 V versus RHE. The high activity of Au₃Cu/CC is attributed to the synergistic interactions between Au and Cu sites in relay catalysis, where Cu exhibits selective activity in the reduction of NO₃⁻ to *NO, while Au demonstrates excellent performance in the subsequent reduction of *NO to NH₃. Additionally, strong d–d orbital hybridization adjusts the d–band center of the alloy NPs, effectively modulating the adsorption energies of NO₃⁻ and *N to facilitate the direct reduction of NO₃⁻ to NH₃. This synergistic electrocatalytic approach offers a novel strategy for designing efficient and multifunctional NO₃⁻RR catalysts.

Extracellular vesicles (EVs) are essential for host–pathogen interactions, mediating processes such as immune modulation and pathogen survival. Pathogen-derived EVs hold significant diagnostic potential because of their unique cargo, offering a wealth of potential biomarkers. In this review, we first discuss the roles of EVs derived from various pathogens in host–pathogen interactions and summarize the latest advancements in pathogen detection based on EVs. Then, we highlight innovative strategies, including novel aggregate materials and machine learning approaches, for enhancing EV detection and analysis. Finally, we discuss challenges in the field and future directions for advancing EV-based diagnostics, aiming to translate these insights into clinical applications.

Aggregation-induced emission (AIE) and thermally activated delayed fluorescence (TADF) are two optoelectronic properties with great potential for applications. However, metal nanoclusters exhibiting both AIE and TADF characteristics have not been extensively studied. This study investigates a binary cocrystal system based on silver nanoclusters—Ag₆(Et₂NCS₂)₆·[Ag₁₁(AdmS)₃(Et₂NCS₂)₆]₂ (1-Ag₆·(Ag₁₁)₂), aiming to explore the synergistic effects between flexible-alkyl dithiol and rigid monothiol ligands. Due to the introduction of Ag₆ structures, the system exhibits enhanced stability and modulated optical properties. The binary tricluster 1-Ag₆·(Ag₁₁)₂ demonstrates significant AIE behavior, with an approximately 15-fold increase in intensity when the water volume fraction (f_w) is 60%. Single-crystal X-ray diffraction analysis indicates that the enhanced AIE effect originates from intercluster hydrogen bonding interactions, which drive the self-assembly of sub-clusters and form hierarchical structures, thereby suppressing ligand rotation. In addition, the system exhibits the TADF phenomenon in the temperature range of 100−175 K. In order to further investigate the effect of ligand variations on optical properties, two unitary clusters, Ag₁₁(AdmS)₃(Et₂NCS₂)₆ (2-Ag₁₁-AS) and Ag₁₁(^tBuS)₃(Et₂NCS₂)₆ (3-Ag₁₁-BS), are synthesized, and their roles in regulating optoelectronic properties are explored through ligand exchange reactions. This study provides important insights for the development of efficient luminescent materials with AIE and TADF properties, highlighting the critical roles of ligand exchange and structural configuration.

Alzheimer's disease (AD) is one of the most prevalent forms of neurodegenerative disease. Although some controversy exists, β-amyloid peptide (Aβ) is recognized to play an essential role in the pathophysiology of AD. The Aβ species are known to exist in various forms, including soluble monomers, oligomers, and insoluble aggregates. Despite extensive efforts to regulate Aβ aggregation, no successful medications have been developed to date. Among the various strategies for AD treatment, phototherapy, including photodynamic therapy (PDT), photothermal therapy (PTT), photopharmacology, and photobiomodulation (PBM) have attracted increased attention because of the spatiotemporal controllability. Representative examples of PDT, PTT, photopharmacology, and PBM are discussed in terms of inhibitory mechanism, the unique properties of materials, and the design of phototherapy modulators. The major challenges of phototherapy against AD are addressed and the promising prospects are proposed. It is concluded that the noninvasive light-assisted approaches will become a promising strategy for intensifying the modulation of Aβ aggregation or promoting Aβ clearance and thus facilitating AD treatment.

Metal–organic hybrid glasses have recently emerged as the fourth member in the glass family due to its versatile hosting ability to various functional ions. However, no luminescent ions have been successfully introduced into hybrid glasses to date. Here, we reported a benign desolvation method, whereby rare-earth-based hybrid glasses (RE(NO₃)₃(C₅H₂N₄)₂ glasses) were rapidly formed within 1 h at a low temperature down to 140°C. Such a facile synthesis was applicable to the full rare-earth family, including Y, Sc, and lanthanide series. The hybrid glasses exhibited not only a high transparency of over 88% but also a high luminescent quantum yield of up to 70%, which demonstrated a high spatial resolution in X-ray imaging screen. Hydrogen bond played a key role in maintaining the structural integrity of the organic-metal framework, which in turn promoted the radiative recombination of excited states including both singlet and triplet states of organic moiety (4,5-dicyanoiazole, or DCI). An efficient energy transfer from DCI to luminescent lanthanide ions, also known as the antenna effect, was probed by both steady-state and time-resolved spectroscopy. Apart from the luminescent hybrid glasses, the incorporation of inert rare-earth ions such as La, Y, and Lu generated a transparent glass of enhanced room-temperature phosphorescence. This work not only improved the synthesis toolbox of metal–organic hybrid glasses, but also provided an ideal transparent matrix for the energy-transfer investigation between organic linker and rare-earth ions.

Cell transplantation therapy in the central nervous system is hindered by limited survival and integration of grafted cells. Biomaterials have emerged as an attractive solution to this problem by providing a protective microenvironment to deliver cells to injured tissues. The design of biomaterials compatible with nervous tissues to promote tissue repair and functional recovery is a focus of neural tissue engineering. A wealth of research has explored different materials and architectures in combination with bioactive cues to promote neural and glial cell growth and maturation. After a brief presentation of biomaterial strategies and cell sources, we review the in vivo evidences about the efficacy of biomaterial and stem cell cotransplantation in (i) enhancing trophic effects, (ii) increasing cell integration, and (iii) achieving functional recovery in preclinical models of stroke, traumatic brain injury, Parkinson's disease, and spinal cord injury. Furthermore, a comprehensive perspective was offered regarding the specific implementation tactics, obstacles, and development orientations of employing biomaterials as critical support to promote cell transplantation.

α-Synuclein (α-syn) forms structurally distinct fibril polymorphs with various pathological activities in different subtypes of synucleinopathies, such as Parkinson's disease (PD). As a unique proteinaceous polymer, the mechanical property of α-syn fibril is a primary determinant of its neurotoxicity, immunogenicity, and seeding and transmission capacity. Nevertheless, how genetic mutations in α-syn fibrils cause varied polymer behaviors remains largely unknown. Using optical tweezers, we quantitatively characterize the mechanical properties of three α-syn fibril variants at the single-molecule level. We find that wild-type α-syn fibrils are generally more sustainable to an axial disruption force than those formed by the disease-causing E46K and A53T α-syn mutants, whereas their heterogeneous elastic properties manifest similarity. Based on the molecular dynamics simulations, the β-sheet motif and the interface between the two protofilaments dominate in stabilizing the fibril structure. Additionally, single-molecule and simulation analysis consistently reveal the force-driven α-syn protein unfolding without a fibril break. Due to the flexible periphery, these subtle structural changes become more pronounced with the E46K fibril. The structure–mechanics relationship of α-syn fibrils built in this work sheds new light on the fibril assembly and disassembly mechanism and the mutant-associated pathogenesis in PD.

Organic lasers hold great promise for enabling a new class of future optoelectronics. Consequently, the development of new organic semiconductors as gain media has recently been the subject of significant interest. The molecular design principle based on Einstein coefficients has been validated for achieving high gain, with para-phenylene-vinylene scaffolds recognized as one of the most crucial frameworks. In this study, we develop a stilbene tetramer derivative, QSBCz, which has significantly increased conjugation compared to the highly efficient laser material, BSBCz, resulting in a remarkably high radiative decay rate and a large gain cross-section. However, we find that the optical losses play a significant role in the light amplification of QSBCz. Indeed, a comprehensive understanding and suppression of detrimental optical loss pathways throughout the lasing process are essential, whereas the losses intrinsically associated with molecules have not been well considered. Although host–guest systems are helpful in preventing concentration quenching in aggregated states, this study reveals notable losses when using common host molecules such as 4,4′-bis(9H-carbazol-9-yl)biphenyl (CBP) and mCBP. In contrast, a BSBCz derivative is successfully employed as the host, leading to improved stimulated emission amplification. These findings indicate the importance of host–emitter interactions in lasing properties and highlight the necessity to optimize host materials for developing new laser dyes.