Dual-functional nanozymes, which are capable of mimicking two distinct enzymatic activities, have recently attracted considerable attention due to their promising application potential across various fields. However, research on advanced dual-functional nanozymes-particularly those with light-modulation capabilities-remains at an early stage. In this study, we successfully synthesized an ultrasmall platinum-based nanozyme using 6-aza-2-thiothymine (ATT) and L-arginine (L-Arg) as protective ligands, denoted as L-Arg/ATT-Pt NCs. Systematic steady-state optical and kinetic analyses revealed their excellent dual-functional catalytic performance toward the oxidation of classic substrate 3,3',5,5'-tetramethylbenzidine (TMB). In the presence of H₂O₂, L-Arg/ATT-Pt NCs exhibited superior peroxidase (POD)-like activity, with a low Michaelis-Menten constant (Kₘ) of 0.098 mM. Under light irradiation, the catalytic behavior switched to oxidase (OXD)-like activity, where photogenerated electron-hole pairs and subsequent reactive oxygen species (ROS) drove the efficient oxidation reaction. Transient absorption spectroscopy further indicated that the light-triggered TMB oxidation initiates on an ultrafast timescale, suggesting an efficient and green catalytic pathway. Therefore, the complementary functionalities of L-Arg/ATT-Pt NCs enhance their catalytic versatility under different conditions. Additionally, the successful application of L-Arg/ATT-Pt NCs in accelerating the oxidation of L-dopa, o-phenylenediamine (OPD) and methylene blue (MB) highlights their potential for catalyzing a wide range of substrates and their applicability in diverse fields.

Luminescent gold nanoclusters (Au NCs) hold promise for various applications due to their unique optical properties. However, enhancing their near-infrared (NIR) photoluminescence quantum yield (QY) and elucidating the underlying emission mechanisms are challenging. In this study, we successfully synthesized glutathione-stabilized Au NCs (GSH-Au NCs) and achieved a NIR phosphorescence QY over 71% in solid. Time-resolved spectroscopy reveals that aggregation effectively suppresses structural vibrations and facilitates intersystem crossing (ISC), while modulation of the Au(0)/Au(I) ratio enhances radiative decay, presenting an effective strategy for improving the phosphorescence of Au NCs. Moreover, the resulting ultrabright GSH-Au NCs exhibit aggregation-induced emission tunable by humidity, demonstrating high potential as optical humidity sensors.

Carbon dots (CDs) have garnered significant attention for developing stimuli-responsive chiroptical nanomaterials. However, CDs featuring simultaneously reversible electronic circular dichroism (ECD) and intrinsic circularly polarized luminescence (CPL) have not yet been reported. Herein, we developed a novel kind of dual-mode chiroptical switches based on achiral CDs through post-modification with L-/D-histidine (L-/D-His). Through a mild amidation reaction, L-/D-His is not only covalently linked to the surface of CDs, but also closely attached to the luminescent centers via non-covalent hydrogen-bonding and π-π interactions, which facilitate efficient chiral transfer from L-/D-His to the luminescent centers of the CDs. Consequently, the chiral His-modified achiral CDs (L-/D-His-CDs) exhibit attractive chiroptical properties with both elegant ECD and intrinsic CPL across the entire visible spectrum. Intriguingly, the ECD and CPL signals of L-/D-His-CDs can be reversibly switched to those of their enantiomers by alternating pH values between neutral and basic conditions. Our results indicate that the pH-modulated protonation and deprotonation of imidazole directly modulate the surface non-covalent interactions, triggering chiral conformational inversion and thereby enabling reversible ECD and CPL signals. This study establishes a facile strategy for the construction of stimuli-responsive chiroptical switches from achiral CDs by rational chiral ligand modifications.

Incorporating platinum (Pt) active species into metal-free covalent organic frameworks (COFs) that possess exceptional structural regularity, robust stability, and a local coordination environment provides inspiration for designing high-performance photocatalysts towards the hydrogen evolution reaction (HER). Nonetheless, rationally modulating metal coordination interactions in Pt-decorated COF photocatalysts, a key factor governing the hydrogen-evolving performance, is fundamentally challenging. Herein, we report a beta-ketoenamine-imine hybrid COF that achieves remarkably enhanced photocatalytic activity through an interfacial metal-coordination strategy. Compared with its conventional beta-ketoenamine counterpart (PaTp-3-NT), the modified PaTp-2-NT nanohybrids deliver an exceptional hydrogen evolution rate of 17.2 mmol & centerdot;g(-1)& centerdot;h(-1) at a low Pt loading. The adjacent & horbar;C & boxH;N & horbar; and & horbar;C & boxH;O chelating motifs in PaTp-2-NT constitute a bidentate coordination geometry that facilitates the precise anchoring of Pt species within the COF framework, yielding a specific Pt-impregnated COF hybrid photocatalyst (PaTp-2-NT@Pt). The modulation of metal-to-ligand charge-transfer (MLCT) pathways in the illuminated PaTp-2-NT@Pt is achieved by tailoring the local coordination environment from Pt (II) to N, O-chelated Pt/COF complexes, thereby promoting extensive electron delocalization across the pi-conjugated framework via d-pi* orbital hybridization. Advanced experimental studies and density functional theory (DFT) calculations further verify the structural evolution, coordination microenvironment, and also the catalytic mechanism.

Carbon dots (CDs) have emerged as versatile photoluminescent nanomaterials with exceptional optical properties and biocompatibility, demonstrating considerable potential in bioimaging, energy conversion, and sensing applications. However, the development of aqueous CDs with tunable red dual-emission remains challenging owing to limitations in electronic energy-level alignment and ongoing debates concerning the photoluminescence mechanisms. Herein, we report a facile hydrothermal synthesis strategy employing trehalose as the carbon precursor and sulfuric acid serving as both an oxidation regulator and a polymerization agent to regulate the distribution of surface states and endow the CDs with dual emission properties. The resulting CDs exhibit well-resolved tunable dual emission bands around 450 and 590 nm, attributed to core states and surface-oxidized states, respectively. Time-resolved spectroscopic investigations reveal that the engineered surface motifs effectively facilitate ultrafast electron migration from the carbon core to the oxidized states. Intriguingly, hydroxyl radicals induce selective static quenching of the surface-oxidation-associated red emission, endowing CDs-based sensors with ultralow detection limits, self-calibration capabilities, and real-time visualization through ratiometric performance. Furthermore, the as-prepared unique CDs have been validated for the reliable quantification of hydroxyl radical levels in plant onion cells under oxidative stress.

Metal halide perovskites (MHPs) have emerged as promising candidates for optoelectronic applications, attributed to their remarkable optical and electrical properties. However, achieving stable and efficient blue emission from MHPs remains a significant challenge due to inherent defects, nonradiative recombination, and phase instability. In this study, a co-doping strategy that integrates Sb3+ and Cl- into CsPbBr3 nanocrystals (NCs) under ambient conditions is presented, yielding blue-emitting CsPbBr3:SbCl3 NCs with a high photoluminescence quantum yield (PLQY) of 95.9% at 466 nm. Structural and spectroscopic analyses reveal that the introduction of Cl- not only increases the bandgap of NC, leading to a blue-shifted emission, but also modulates the rigidity of PbX6 4- octahedra, thereby facilitating the substitution of Sb3+ for Pb2+. Meanwhile, Sb3+ doping effectively suppresses Auger recombination and mitigates surface defects. The co-doped NCs exhibit remarkable stability, maintaining over 80% of their PL intensity after prolonged exposure to elevated temperatures, as well as over 90% in aqueous environments or under ultraviolet irradiation. Density functional theory results further indicate a lower binding energy for the co-doped NCs, suggesting enhanced lattice stability. Furthermore, a pure-blue light-emitting diode incorporating these NCs demonstrates stable luminescence performance under varying driving currents.

Room-temperature phosphorescence (RTP) carbon dots (CDs) have attracted extensive attention due to their afterglow properties and promising potential in optical information and encryption fields. However, achieving tunable and broadband RTP CDs-based afterglow materials remains a great challenge for practical applications. Herein, we constructed broadly tunable afterglow CDs-based hybrid systems by employing cascade Forster resonance energy transfer (FRET) for fingerprint recognition and anticounterfeiting. The as-prepared CDs composites exhibit excellent green RTP properties with a quantum yield of 21.7 % and a lifetime of 1.05 s. Combination of the RTP CDs as the energy donor and Sulforhodamine 101 (SR101), Rhodamine B or Rhodamine 6G as the acceptor in polyvinyl alcohol (PVA) film, the afterglow spectrum of RTP CDs/dye/PVA film is markedly extended to the red region through an efficient triplet-singlet FRET. The sequential incorporation of SR101 and Oxazine 170 with RTP CDs further broadens the afterglow spectrum of CDs/SR101/Oxazine170/PVA film covering from green to near-infrared regions due to the cascade relayed FRET. The flexible FRET configuration of highly emissive RTP CDs with various dye acceptors endows the CDs/dyes/PVA hybrid films with tunable color and broadband afterglow properties for fingerprint recognition and anticounterfeiting applications.

Hybrid chiral nanostructures hold great promise for next-generation photonic, catalytic, and biomedical technologies. However, the construction of hybrid chiral nanoparticles (NPs) with tunable chiroptical activity, high anisotropy factor (g-factor), and broad application potential remains a considerable challenge. Here, we report a chiral plasmon-dielectric coupling strategy to construct helicoid Au core-TiO2 shell nanostructures (GNH@TiO2) with enhanced and tunable chiroptical activity. By precisely controlling the TiO2 shell thickness, the optical activity profiles of the hybrid nanostructures are effectively extended to the near-infrared region with an enhanced g-factor up to 0.14. Systematic analysis indicates that the shell-dependent g-factors of GNH@TiO2 hybrids are closely associated with the chiral configuration of the hybrid structure induced by the coating of TiO2, as well as the electron transfer dynamics between GNH and TiO2. Moreover, the chiral GNH@TiO2 with a high g-factor exhibits asymmetric color modulation capability. Our findings provide a successful platform for engineering chiral hybrid nanostructures with tunable optical activities and mechanistic insights into the chiral plasmon-semiconductor interactions.

Afterglow photoluminescent (PL) carbon dots (CDs)-based materials with tunable and time-dependent colors are highly desirable for their potential applications in high-level information encryption and anti-counterfeiting, but their construction remains a significant challenge. Herein, we report several broadband and dynamic afterglow PL CDs@BA using 2,2 '-Dithiodibenzoic acid (DTSA) as the precursor of CDs and boric acid (BA) as the matrix. A facile thermal treatment significantly regulates the distribution among the cyan-green emission edge states and red emission surface states associated with the oxygen-containing groups of CDs@BA. The balanced contributions from different emissive states with distinct spectra, lifetimes on both nanoseconds and milliseconds scales, and relative proportions endow the CDs@BA with the ultrabroad and afterglow PL that cover almost the entire visible region. The broadband PL under light excitation mainly originates from the emissions of different singlet states, and the broadband afterglow PL is attributed to the combined delayed fluorescence (DF) of different singlet-triplet states. In particular, CDs@BA demonstrates an evident time-dependent afterglow color changing from tangerine to cyan-green, due to an enhanced contribution to the afterglow from the red DF component. Furthermore, these CDs@BA manifest promising potentials for white-light display, optical encryption, and time- resolved anti-counterfeiting applications. Our findings provide an effective strategy to construct broadband and dynamic afterglow CDs-based materials and are significant for understanding the related photophysical mechanisms.

Metal halide perovskites (MHPs) have emerged as promising candidates for optoelectronic applications, attributed to their remarkable optical and electrical properties. However, achieving stable and efficient blue emission from MHPs remains a significant challenge due to inherent defects, nonradiative recombination, and phase instability. In this study, a co‐doping strategy that integrates Sb 3+ and Cl − into CsPbBr 3 nanocrystals (NCs) under ambient conditions is presented, yielding blue‐emitting CsPbBr 3 :SbCl 3 NCs with a high photoluminescence quantum yield (PLQY) of 95.9% at 466 nm. Structural and spectroscopic analyses reveal that the introduction of Cl − not only increases the bandgap of NC, leading to a blue‐shifted emission, but also modulates the rigidity of PbX 6 4− octahedra, thereby facilitating the substitution of Sb 3+ for Pb 2+ . Meanwhile, Sb 3+ doping effectively suppresses Auger recombination and mitigates surface defects. The co‐doped NCs exhibit remarkable stability, maintaining over 80% of their PL intensity after prolonged exposure to elevated temperatures, as well as over 90% in aqueous environments or under ultraviolet irradiation. Density functional theory results further indicate a lower binding energy for the co‐doped NCs, suggesting enhanced lattice stability. Furthermore, a pure‐blue light‐emitting diode incorporating these NCs demonstrates stable luminescence performance under varying driving currents.

Carbon dots (CDs) with ultra-broadband and time-dependent afterglow photoluminescence (PL) are pivotal for next-generation anti-counterfeiting and dynamic information encryption, yet their rational design remains a formidable challenge in terms of spectral-temporal tunability and mechanistic clarity. Herein, we propose a molecular engineering strategy to synthesize CDs@B2O3 via a one-step fusion heating process, using levofloxacin and 1-pyrenylboronic acid as the carbon source precursors within a boric acid matrix. By properly modulating the electronic state distribution between the green-emitting surface states and the red-emitting core states of the CDs, we achieve full coverage of the visible spectrum from green to the near-infrared region. Mechanistic investigations reveal that the broadband afterglow arises from the synergistic delayed fluorescence (DF) of Nheterocyclic surface molecular states and large conjugated domains that activate red core states. Notably, the increased conjugation degree of the carbon core in L,P-CDs@B2O3 results in a higher proportion of red-emitting states and longer afterglow time, enabling a unique color-changing afterglow that transitions from an initial green through yellow and finally to red within 1 s. The time-resolved afterglow characteristics facilitate highcapacity graphical anti-counterfeiting, demonstrating promising applications in graphical security and information storage with spatiotemporal resolution. These findings not only provide an effective approach for designing smart afterglow nanomaterials but also elucidate the structure-emission relationship in carbon-based systems, offering insights into the rational engineering of multi-modal photoluminescent materials.

Inorganic chiral hybrid nanostructures exhibit distinct chiroptical properties and functionalities compared to achiral systems and have attracted extensive attention due to their promising applications in photocatalytic, photoelectronic and information fields. However, significant challenges remain in constructing chiral hybrid nanostructures and exploring their chirality-dependent properties. Herein, we report chiral plasmonic metal-semiconductor core-shell nanostructures utilizing chiral gold nanohelicoid I (GNH I) as the core and titanium dioxide (TiO2) as the shell (denoted as GNH I@TiO2), and investigate their chirality-dependent photocatalytic properties. The results indicate the chiroptical activity of GNH I@TiO2 can be effectively regulated by varying the thickness of the TiO2 shell. The femtosecond transient absorption spectra (FTAS) study indicates that the effective coupling between the chiral core GNH I and the shell TiO2 not only promotes the chirality-dependent generation of hot carriers but importantly reduces the recombination of the generated carriers, leading to the chirality-dependent photocatalytic efficiencies. Consequently, the chiral GNH I@TiO2 hybrid nanostructures demonstrate chirality-dependent photocatalytic features when exposed to circularly polarized light (CPL). This work demonstrates a successful example of constructing chiral hybrid nanomaterials to enhance chiral light-matter interactions and facilitate their applications as potential chiroptical devices.

The high crystalline covalent triazine framework-1 (CTF-1), composed of alternating triazine and phenylene, has emerged as an efficient photocatalyst for solar-driven hydrogen evolution reaction (HER). However, it is of great challenge to further improve photocatalytic HER performance via increasing crystallinity due to its near-perfect crystallization. Herein, an alternative strategy of scaffold functionalization is employed to optimize the energy band structure of crystalline CTF-1 for boosting hydrogen-evolving activity. Guided by the computational predictions, versatile CTF-based polymer photocatalysts are prepared with different functional groups (OH, NH2, COOH) using binary polymerization for practical hydrogen production. Experiment evidence verifies that the introduction of a limited number of electron-donating groups is sufficient to maintain high crystallinity in CTF, modulate the band structure, broaden visible light absorption, and consequently enhance its photophysical properties. Notably, the functionalization with OH exhibits the most positive effect on CTF-1, delivering a photocatalytic activity with a hydrogen-producing rate exceeding 100 mu mol h-1. In order to promote photocatalytic hydrogen evolution reaction in covalent triazine frameworks (CTFs), it is imperative to functionalize highly crystalline CTFs. Guided by theoretical predictions and calculations, modifications are applied to CTF-1 using functional groups with varying electronic effects. The improved photocatalytic activity is witnessed by the incorporation of electron-donating groups. Experimental findings indicate that chemical modification optimizes the valence band position, broadens visible light absorption, and accelerates the charge carrier dynamics. image

Perovskite luminescent materials have been extensively investigated due to their comprehensive applications for full-color display, lighting, and communication. However, the development of blue-emissive perovskites has seriously lagged behind that of green and red counterparts, primarily because of their low photoluminescence quantum yield (PL QY) and poor stability. Here, we prepared blue-emissive CsPbCl0.9Br2.1 perovskite nanocrystals (PeNCs) and enhanced their QY from 61.3% to 90.4% by regulating the chain lengths of ligands. Post-treated PeNCs also exhibit good stability, their PL intensity is maintained at about 90% after storage at ambient conditions for 10 days. The exciton dynamics results obtained from time-resolved fluorescence spectra and transient absorption spectra show that dodecyldimethylammonium bromide (DDAB), featuring double 12-hydrocarbon chains, is more capable of passivating surface defects and inhibiting non-radiative composites than the other double 8- or double 16-carbon chain ligands, which greatly improved the probability and rate of radiative recombination. Subsequently, the mechanism of ligand chain length regulation on the PL properties and stability of PeNCs was analyzed in terms of ligand-NC surface interaction, ligand polarity, hydrophobicity, and spatial effects. Furthermore, the device based on DDAB-CsPbCl0.9Br2.1 demonstrated stable EL and long operation lifetime, indicating its significant potential as an efficient blue emitter for backlighting in display technologies.

Photoluminescence (PL) metal nanoclusters (NCs) have attracted extensive attention due to their excellent physicochemical properties, good biocompatibility, and broad application prospects. However, developing water-soluble PL metal NCs with a high quantum yield (QY) and high stability for visual drug delivery remains a great challenge. Herein, we have synthesized ultrabright l-Arg-ATT-Au/Ag NCs (Au/Ag NCs) with a PL QY as high as 73% and excellent photostability by heteroatom doping and surface rigidization in aqueous solution. The as-prepared Au/Ag NCs can maintain a high QY of over 61% in a wide pH range and various ionic environments as well as a respectable resistance to photobleaching. The results from structure characterization and steady-state and time-resolved spectroscopic analysis reveal that Ag doping into Au NCs not only effectively modifies the electronic structure and photostability but also significantly regulates the interfacial dynamics of the excited states and enhances the PL QY of Au/Ag NCs. Studies in vitro indicate Au/Ag NCs have a high loading capacity and pH-triggered release ability of doxorubicin (DOX) that can be visualized from the quenching and recovery of PL intensity and lifetime. Imaging-guided experiments in cancer cells show that DOX of Au/Ag NCs-DOX agents can be efficiently delivered and released in the nucleus with preferential accumulation in the nucleolus, facilitating deep insight into the drug action sites and pharmacological mechanisms. Moreover, the evaluation of anticancer activity in vivo reveals an outstanding suppression rate of 90.2% for mice tumors. These findings demonstrate Au/Ag NCs to be a superior platform for bioimaging and visual drug delivery in biomedical applications.

Sonodynamic therapy (SDT) has attracted considerable attention owing to its large penetration depth. However, the low efficiency of traditional sonosensitizers and the hypoxia environment of deep tumors hinder their therapeutic effect in practical application. Herein, the Au@TiO2-hemoglobin loaded liposome (Au@TiO2-Hb-Lip) complex has been constructed to improve the efficiency of SDT against hypoxic tumors. The results indicate that the generated carriers upon ultrasound activation of TiO2 nanoparticles (NPs) can be effectively trapped by Au NPs, and the production of reactive oxygen species is increased by two times compared to that of bare TiO2 NPs. Particularly, the introduction of liposomes as a carrier and hemoglobin as an oxygen supplier not only prevents the aggregation of Au@TiO2 NPs in the blood environment but also improves the adaptability of Au@TiO2-Hb-Lip to hypoxic tumors. These synergic actions of different moieties in Au@TiO2-Hb-Lip sonosensitizer significantly enhance the SDT efficiency.

The emission of cyan light (470-500 nm) plays a vital role in the visible light spectrum and is essential for applications such as lighting, displays, and optical communication. Inorganic cesium lead bromide perovskite quantum dots (CsPbBr3 PQDs) have made significant progress in the field of luminescence materials and devices, however, the lack of techniques to obtain highly emissive and stable cyan-emitting CsPbBr3 PQDs has limited their device applications. Here, it is demonstrated that the complete surface passivation by treatment of didodecyldimethylammonium bromide (DDAB) and lead bromide, which can enhance the photoluminescence and stability of cyan emitting CsPbBr3 PQDs. In particular, the photoluminescence quantum yield of CsPbBr3 QDs can be greatly improved from 10.5% to 83.8%. Through an effective PMMA passivation, the obtained stable and bright CsPbBr3 PQDs composite films as the cyan color converters can effectively emit the cyan light to fill the "cyan gap" of white light-emitting diode (WLED). The color rendering index value of such WLED is remarkably enhanced from 73.6 to 82.5. This study paves the way for the application of PQD color converters in the next generation of full-visible-spectrum WLED lighting.

Monitoring the copper ion (Cu2+) levels has attracted considerable attention due to its significance in environmental and physiological applications. Here, we report on red dual-emission carbon dots (CDs) with a 43% quantum yield and without excitation wavelength dependence for probing Cu2+ in vitro and in vivo. The solid coordination of Cu2+ with the surface groups of CDs generates an asynchronous fluorescent quenching of CDs and enables ultrasensitive detection of Cu2+ in vitro. The intensity ratio of fluorescence at 605 and 650 nm (F-605/F-650) shows a linear response to Cu2+ concentration ranging from 0 to 1.1 mu M, with an ultralow detection sensitivity of 0.58 nM. Moreover, the as-prepared CDs show good stability, anti-interference capability, low cellular toxicity, and exceptional ability to penetrate plant cell walls, endowing the CDs with excellent bioimaging potentials and tracking the dynamic levels of Cu2+ in living cells.

Preparing chiral plasmonic nanoparticles (NPs) with strong chiroptical responses is crucial in numerous fields including constructing optical materials, chiral sensing, and chiral-dependent biological processes. However, precise regulation over the chiral optical activity and chiral configuration of plasmonic NPs is still a challenge. In this work, we report Au helicoid NPs with different chiral structures and reversal chirality directed by the oligomeric structure of inducer glutathione (GSH). By precisely controlling the oligomeric structure of GSH and other synthetic parameters, we successfully prepared chiral Au helicoid NPs with a high anisotropy factor of 0.03. The obtained chiral Au NPs demonstrated an excellent performance in discriminating penicillamine (Pen) enantiomers. Our findings provide a construction strategy for chiral Au NPs and contribute insight into the regulation effect of chiral inducers on the growth of chiral metal NPs.