Nonradiative Transition Process Research Articles

Dual photosensitizers material for photodynamic theraphy

Abstract Fluoride-based upconversion luminescent materials have the advantage of low phonon energy, which can effectively reduce the non-radiative transition process, so that materials have higher luminous efficiency than other matrix materials. The core–shell NaGdF4:Er3+, Yb3+ @NaGdF4:Tm3+, Yb3+ nanoparticals were synthesized by thermal decomposition method. The core–shell structure can effectively avoid the surface quenching effect, meanwhile, Tm3+ in the shell transmits part of the photons in its excited state to Er3+, effectively enhancing the red emission of Er3+ and improving the luminous efficiency of the samples as a whole. The samples were further coated with a layer of mesoporous silica(mSiO2), where the photosensitizer(PS) Ce6 (red light activated) and MC540 (blue-green light activated) were compounded on through covalent bonds and electrostatic forces, respectively. So that three visable lights include red, green, and blue are all emitted from the sample to activate the PSs to produce reactive oxygen species (ROS) under 980 nm laser irradiation. In cells experiments, the samples were modified with folic acid (FA), which can mediated the cancer cells to target endocytosis. Notable photodynamic therapy (PDT) efficiency was observed under this dual-photosensitizers composite samples for its ROS generation.

Study of the Energy Crossing Between Excited States Affected by the Electronegativity of Substituents for Three 4-Azido-1,8-naphthalimide Derivatives.

Rapid detection of H2S is crucial for human physiological health and natural ecosystems. In this study, the fluorescent sensing mechanisms of three 4-azido-1,8-naphthalimide-based fluorescent probes to monitor H2S were theoretically investigated by density functional theory and time-dependent density functional theory. The potential energy curve of the charge transfer (CT) state has a crossover with that of the locally excited (LE) state proved by the constructed linear interpolating internal coordinate pathway. Thus, the transform takes place from the LE state to the CT state causing the fluorescence quenching of the probes from a nonradiative transition process of the CT state. The distance between the Franck-Condon point and the minimal energy conical intersection becomes larger with the increase of the electronegativity of substituents on the 1,8-naphthalimide fluorophore. In addition, the degree of charge separation is closely related to the energy difference between the CT and the LE states which are also essentially affected by the electronegativity of the substituents. Since the electronegativity of the substituents has proved important for the probes, our work lays a certain theoretical foundation for the design and synthesis of more sensitive 4-azido-1,8-naphthalimide-based fluorescent probes.

Impact of the Peripheral Ligand Layer on the Excited-State Deactivation Mechanism of Au38S2(S-Adm)20 and Au30(S-Adm)18 (S-Adm = Adamantanethiolate) Clusters.

Gold nanoclusters are ideal fluorescent labels for biological imaging, disease diagnosis, and treatment. Understanding the origin of the photoluminescence phenomenon in ligand-protected gold nanoclusters is crucial for both basic science and practical applications. In this study, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed to study the mechanism of excited state deactivation of Au38S2(S-Adm)20 and Au30(S-Adm)18 (S-Adm = adamantanethiolate) clusters, which have similar sizes and compositions. The computational results indicate that the differences in structural symmetry and peripheral ligand layer lead to quite different excited state deactivation mechanisms and excited state lifetimes in Au38S2(S-Adm)20 and Au30(S-Adm)18. Specifically, the μ3-S atoms and bridging thiolate (SR) in the ligand layer of Au38S2(S-Adm)20 significantly suppress the structural relaxation of ligand motifs, resulting in a prolonged excited state lifetime and higher quantum yield. For the Au30(S-Adm)18, due to the symmetry forbidden and large structural relaxation of the ligand shell, a rapid nonradiative transition process resulted. This study provides new insights into how the photoluminescence of ligand-protected gold nanoclusters is influenced by their structure and symmetry.

Ultralong room temperature phosphorescence and broad color-tunability persistent luminescence via new strategy

Pure organic materials with ultralong room-temperature phosphorescence (RTP) and persistent luminescence in broad color gamut exhibit tremendous potential and broad application prospects due to their unique optical properties. This article proposes a simple strategy, polyatomic synergistic effect, to endow persistent luminescent materials with ultralong lifetime and broad color-tunability through polyatomic synergistic effect and non-traditional phosphorescence resonance energy transfer (PRET). By leveraging the polyatomic synergistic effect to enhance the intersystem crossing (ISC) in bibenzimidazole (BBI) derivatives and suppress the non-radiative transition process, ultralong persistent room-temperature phosphorescence has been successfully achieved after incorporating BBI-Cl-M into poly(methyl methacrylate) (PMMA) to form a rigid matrix(BBI-Cl-M@PMMA). Specifically, the ester functionalized bibenzimidazole with modified chlorine on molecular skeleton (BBI-Cl-M) demonstrates a remarkable phosphorescent lifetime (τp) of up to 256.4 ms. In addition, the behaviors and mechanism of RTP via polyatomic synergistic effect have been further understood by theoretical calculation and single crystal analysis. Subsequently, utilizing BBI-Cl-M as the energy donor and Rhodamine B (RB) as the energy acceptor, persistent and multicolor organic afterglow covering from green to red has been realized successfully by simply regulating the doping composition and concentration of PRET systems. These RTP materials have also been applied in underwater afterglow emission and multilevel anti-counterfeiting technology successfully.

Theoretical study of the substituent effects on the ESIPT mechanism of salicylideneaniline and the TICT photochemistry reactions.

The study of salicylideneaniline (SA) and its derivatives is critical due to their special photophysical properties and environmental sensitivity. In this work, the density time-dependent functional theory (TDDFT) and complete-active-space self-consistent-field (CASSCF) methods were carried out to calculate the substituent effect on excited-state properties and dynamics of SA derivatives. We found the para-substitution triggers the excited-state intramolecular proton transfer (ESIPT) reaction, exhibiting the dual-fluorescent phenomena. However, the meta- and ortho-substitutions impel the non-radiative transition process along the minimum energy conical intersection (MECI), forming the twisted intramolecular charge transfer (TICT) state to prevent ESIPT. This investigation of substituent effects on the photochemical processes and photophysical properties will provide the benchmarks for the design of fluorescent materials.

A green large-scale fabrication of cellulose-based multifunctional fluorescent fibers for versatile applications

Luminescent fibers, particularly deriving from sustainable polymers, exhibit considerable potential for application in flexible smart materials. However, the large-scale preparation of fluorescent fibers has been hindered by the instability of physically doped fluorescent substrates or the complexity and cost of chemical modification. Herein, a scalable and green strategy for the fabrication of cellulose-based multifunctional fluorescent fibers is presented. Specifically, based on the clustering-triggered emission (CTE) mechanism, cellulose acetoacetate (CAA) fluorescent fibers are continuously synthesized for the first time through a lab-scale pilot wet-spinning machine. Subsequent derivatization processes are implemented to further improve the fluorescent properties of CAA fibers by promoting the radiation transition while suppressing nonradiative transition processes and impart additional functionalities to CAA fibers. The resulting fibers exhibit integrated performances with bright cyan-blue fluorescence emission (quantum yield of 36.07%), excellent UV-blocking (UPF being up to 72.04), hydrophobic (contact angle of 141.9°), and effective antibacterial properties. Benefiting from their flexible and superior fluorescent performances, the resulting fibers have demonstrated potential applications in the fields of wearable fluorescent displays, information encryption, and fluorescent handicrafts. More interestingly, the multifunctional fluorescent fibers can be processed into clothes, showing promising application in multiple fields, such as multifunctional textiles, antibacterial dressing etc. This strategy not only provides a rational approach for the scalable production of one-dimensional (1D) multifunctional fluorescent material but also inspires the development of non-traditional sustainable fluorescent polymers.

Mechanochemical Synthesis of Cuprous Complexes for X-ray Scintillation and Imaging.

Cuprous complex scintillators show promise for X-ray detection with abundant raw materials, diverse luminescent mechanisms, and adjustable structures. However, their synthesis typically requires a significant amount of organic solvents, which conflict with green chemistry principles. Herein, we present the synthesis of two high-performance cuprous complex scintillators using a simple mechanochemical method for the first time, namely [CuI(PPh3)2R] (R = 4-phenylpyridine hydroiodide (PH, Cu-1) and 4-(4-bromophenyl)pyridine hydroiodide (PH-Br, Cu-2). Both materials demonstrated remarkable scintillation performances, exhibiting radioluminescence (RL) intensities 1.52 times (Cu-1) and 2.52 times (Cu-2) greater than those of Bi4Ge3O12 (BGO), respectively. Compared to Cu-1, the enhanced RL performance of Cu-2 can be ascribed to its elevated quantum yield of 51.54%, significantly surpassing that of Cu-1 at 37.75%. This excellent luminescent performance is derived from the introduction of PH-Br, providing a more diverse array of intermolecular interactions that effectively constrain molecular vibration and rotation, further suppressing the nonradiative transition process. Furthermore, Cu-2 powder can be prepared into scintillator film with excellent X-ray imaging capabilities. This work establishes a pathway for the rapid, eco-friendly, and cost-effective synthesis of high-performance cuprous complex scintillators.

Efficient Near‐Infrared Organic Light‐Emitting Diodes with Emission Peak Above 900 nm Enabled by Enhanced Photoluminescence Quantum Yields and Out‐Coupling Efficiencies

AbstractNear‐infrared organic light‐emitting diodes (NIR OLEDs) with emission peak above 900 nm are attractive for many emerging applications, spanning from bioimaging to light detection and ranging. However, the device performance of NIR OLEDs is generally limited by the low quantum efficiency of emitters because of the fast nonradiative transition process imposed by energy‐gap law and aggregation quenching. So far, only a few Pt(II) complexes delivering external quantum efficiency (EQE) over 1% are reported, while there is no comparable electroluminescence in heavy‐metal‐free fluorescent organic emitters. Here, NIR OLEDs centered at 934 nm by blending an acceptor–donor–acceptor type molecule Y11 into a polymer host poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐alt‐(4,4′‐(N‐(4‐sec‐butylphenyl)diphenylamine) (TFB) are reported. The OLEDs show a remarkably high EQE of 1.72%. Moreover, owing to a low turn‐on voltage (≈0.9 V), the resultant NIR OLEDs have an electricity‐to‐light power efficiency surpassing 20 mW W−1. The improved device performance can be attributed to enhanced photoluminescence quantum yields (PLQYs) of the blends owing to suppressed aggregation quenching, and favorable light extraction from the emissive layer. Such values are the highest among fluorescent OLEDs with electroluminescence above 900 nm.

Cyano modified triphenylmethyl radical skeletons: higher stability and efficiency.

We introduced cyano groups to replace chlorine atoms in the tris(2,4,6-trichlorophenyl)methyl (TTM) radical skeleton, resulting in two cyano-modified TTM skeletons. The incorporation of cyano groups effectively suppresses nonradiative transition processes and lowers the frontier molecular orbital energy levels compared to those of the TTM radical. Consequently, enhanced photoluminescence quantum efficiency (PLQE) and a shift towards longer-wavelength emission in solution were achieved. Furthermore, the cyano-modified TTM skeletons exhibited improved stabilities. The development of these two skeletons adds diversity to stable organic luminescent radical skeletons.

Ag6 Cu8 (C=CAr)14 (DPPB)2 : A Rigid Ligand Co-Protected Bimetallic Silver(I)-Copper(I) Cluster with Room-Temperature Luminescence.

Metal clusters have become increasingly important in various applications, with ligands playing a crucial role in their construction. In this study, we synthesized a bimetallic cluster, Ag6 Cu8 (C=CAr)14 (DPPB)2 (Ag6 Cu8 ), using a rigid acetylene ligand, 3,5-bis(trifluoromethyl)phenylacetylide. Through single-crystal structure characterization, we discovered that the butterfly-shaped Ag2 Cu2 motifs were subject to distortion due to steric hindrance imposed by the rigid ligand. These motifs assembled together through shared vertices and edges. Mass spectrometry analysis revealed that the primary fragments detected during electrospray ionization (ESI) testing corresponded to the Ag2 Cu2 motifs. Furthermore, we conducted a comprehensive investigation of the cluster's solution properties employing 31 P NMR, UV-vis absorption, and photoluminescent measurements. In contrast to previously reported Ag/Cu bimetallic clusters protected by flexible ligands, Ag6 Cu8 protected by rigid ligands exhibited intriguing room temperature fluorescence properties alongside excellent thermal stability. DFT calculations on Ag6 Cu8 and Ag6 Cu8 with the rigid aromatic ring removed revealed that the presence of the rigid aromatic ring can lower the electronic energy levels of the cluster, and reduce the energy gap from 4.05 eV to 3.45 eV. Moreover, the rigid ligand further suppressed the non-radiative transition process, leading to room temperature fluorescence emission.

Based on FRET to construct color-tunable ultralong lifetime room temperature phosphorescent carbon dots in aqueous solution

Room temperature phosphorescent (RTP) Carbon Dots have been capturing increasing attention in recent years, while building a general method to adjust the emission color of RTP carbon dots is still a big challenge. Herein we report a simple method that combine the carbon nanodots and dyes (R6G and DCF) in SiO2 nanosphere to get a series of multicolor RTP nanodots (CD@SiO2@dye) with long lifetime in aqueous solution. Leverage on chitosan quaternary ammonium as matrix and diethylenetriamine as N-doping resource to form a cross-linked skeleton as a luminescent center (namely CD), and a rigid network is formed by silica encapsulation (CD@SiO2) to restrict the non-radiative transition process to generate the phosphorescence. The CD-based composites, with 1.10 s green (503 nm) phosphorescence emission, serve as activator to stimulate the corresponding luminescence of organic dyes. Then, based on Förster resonance energy transfer (FRET) process from CDs (as donor) to organic dyes (as acceptor) under UV excitation, the CD@SiO2@R6G emit ultra-long lifetime (1.13 s) orange-yellow (570 nm) afterglow, and CD@SiO2@DCF emit ultra-long lifetime (1.20 s) yellow-green afterglow (530 nm). Furthermore, it also achieves RTP colors control when the ratio of CDs and the dyes changes, the ratio of green emission and dye’s emission activated by CDs will gradually change as well. These kinds of materials keep the inherent advantages of low toxicity and luminous stability, and achieve adjustable RTP color in aqueous solution. Our research provides a strategy to synthesize water-soluble long-life RTP CDs with adjustable color and lifetime.

Turn on the luminescence channel by the suppression of conical intersection process for the sulfur-containing hydrogen-bonded molecules

The sulfur-containing hydrogen bonds exhibit notable potential in gene and protein engineering. As an important research direction of sulfur-containing hydrogen bonding dynamics, the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton has garnered significant interest. Recently, Chou et al. synthesized a series of sulfur-containing H-bonded molecules, inclusive of 3-thiolflavone (3 TF), its trifluoromethyl derivative (3FTF), and its diethylamino derivative (3NTF), thereby inaugurating a new chapter in the ESIPT reaction of the thiol proton. Nevertheless, many open issues cannot be answered solely by experimental means and call for a detailed theoretical investigation, especially the relationship between the molecular excited-state properties and different luminescence properties of the three molecules. Herein, we validate that the molecules undergo the ESIPT reaction of the thiol proton and identify the time scale through the time-dependent density functional theory (TDDFT) calculation. Moreover, employing the spin-flip TDDFT approach, the analysis of the non-radiative transition process reveals that difference in Gibbs free energy of activation (ΔG⧧) for the transition from Frank-Condon point to minimum energy conical intersection (MECI) point primarily accounts for the different luminescence properties of the three molecules. Besides, we also reveal the reason for the abnormal blue-shifted fluorescence of the 3NTF in the aggregated state by the ONIOM (TDDFT: UFF) strategy. These findings are favorable to understanding the luminescence mechanism of sulfur-containing H-bonded molecules and provide a reference for the synthesis and design of the luminescent materials based on the molecules with thiol proton transfer properties.

The improved scintillation performances and X-ray imaging of Lu2O3:Pr3+ nanoparticles induced by Sm3+ doping

Lu2(1-x)Pr2xO3 nanoscintillators (x = 0.0005, 0.001, 0.0015, 0.003, 0.005) with excellent red emission and a response time of 185.7 μs were synthesized by a coprecipitation method. It is found that both photoluminescence and radioluminescence intensities show an initial rising and then decreasing trend with increasing Pr3+ concentration and the strongest intensity can be obtained at x = 0.001. By determining the average distance between Pr and O, the radiative transition processes from 3P0 and 1D2 to 3H4 and nonradiative transition process from 3P0 to 1D2 can be confirmed. Meanwhile, the afterglow level of Lu2O3:Pr3+ nanoscintillators with an average size of 112.3 nm was found to be 2190 ppm. Based on the spectral data and density functional theory calculations, the afterglow can be related to PrLu· traps due to the presence of Pr4+ in Lu2O3:Pr. When Sm3+ ions were doped into Lu2O3:Pr3+, it is found that it leads to the decreased creation of Pr4+, the reduced afterglow level and the improved radioluminescence. By means of Lu2O3:Pr3+, Sm3+ nanoparticles being dispersed into polymethyl methacrylate (PMMA) polymer, PMMA-Lu2O3:Pr3+, Sm3+ composite films with fast response time and radiation resistance were prepared by a rotating coating method. The static X-ray imaging with a spatial resolution of 5.5 lp/mm using the composite film as an imaging screen was realized at extremely low safe dose of 4.6 μGy. Meanwhile, for the broken electric wire used as an object, the clear X-ray image can be observed. Our results suggest that Lu2O3:Pr3+, Sm3+ nanoscintillators have potential applications in medical imaging and nondestructive testing.

Remote Effect from Boron Cluster: Tunable Photophysical Properties of o-Carborane-Based Luminogens.

We proposed a new molecular design strategy that the o-carboranyl group is attached as "an innocent unit" to the remote side of luminogens to tune photophysical properties. To verify this strategy, two o-carborane-based compounds with asymmetric molecular geometry were designed and synthesized. Photophysical properties of o-carborane-based luminogens were investigated on the basis of UV-Vis spectra, photoluminescence spectra, crystal structure analysis and theoretical calculations. The results indicate that the o-carboranyl group has a slight effect on the energy gap between the ground state (S0 ) and the first excited state (S1 ) in the solution state but a significant effect on the energy gap between S0 and S1 in the solid state. Besides, the radiative and non-radiative transition processes are modulated by the o-carboranyl unit. This leads to emission quenching in the solution state but an enhanced luminous efficiency in the aggregate state with a typical aggregation-induced emission (AIE) property.

Modulating Non‐Radiative Deactivation via Acceptor Reconstruction to Expand High‐Efficient Red Thermally Activated Delayed Fluorescent Emitters

AbstractThe development of high‐efficient red thermally activated delayed fluorescent (TADF) materials is crucial to expanding their applications. Here, the acceptor reconstruction strategies of acceptor bonding and acceptor fusing in donor–acceptor‐type materials to modulate their nonradiative deactivation process and emission color for expanding high‐efficient red TADF emitters are presented. They are applied to design novel red TADF emitters TXO‐b‐TPA and TXO‐f‐TPA based on non‐red thioxanthone oxide (TXO) acceptor. Compared to TXO‐based emitter TXO‐TPA, these acceptor reconstruction strategies enable red‐shifted (48–88 nm) and efficient red TADF emission (600–640 nm). Their radiative and nonradiative transition processes can be modulated by the different molecular orbital and excited state distributions based on their acceptor structural differences, which results in a dramatic enhancement of their organic light‐emitting diode (OLED) device efficiencies from 1.21/3.63% (TXO‐f‐TPA) to 20.9% (TXO‐b‐TPA). These results confirm that the acceptor reconstruction strategies provide a viable solution for overcoming the limitations of previous red TADF emitters. Moreover, the retrieval of reported TADF materials can further demonstrate that these acceptor reconstruction strategies can be transferrable to more non‐red TADF materials to expand high‐efficient red‐shift and/or red TADF materials.

Effective Design Strategy for Aggregation-Induced Emission and Thermally Activated Delayed Fluorescence Emitters Achieving 18% External Quantum Efficiency Pure-Blue OLEDs with Extremely Low Roll-Off.

High-color purity organic emitters with a simultaneous combination of aggregation-induced emission (AIE) and thermally activated delayed fluorescence (TADF) characteristics are in great demand due to their excellent comprehensive performances toward efficient organic light-emitting diodes (OLEDs). In this work, two D-π-A-structure emitters, ICz-DPS and ICz-BP, exhibiting AIE and TADF properties were developed, and both the emitters have narrow singlet (S1)-triplet (T1) splitting (ΔEST) and excellent photoluminescence (PL) quantum yields (ΦPL), derived from the distorted configurations and weak intra/intermolecular interactions, suppressing exciton annihilation and concentration quenching. Their doped OLEDs based on ICz-BP provide an excellent electroluminescence external quantum efficiency (ηext) and current efficiency (ηC) of 17.7% and 44.8 cd A-1, respectively, with an ηext roll-off of 2.9%. Their nondoped OLEDs based on ICz-DPS afford high efficiencies of 11.7% and 30.1 cd A-1, with pure-blue emission with Commission Internationale de l'Éclairage (CIE) coordinates of (0.15, 0.08) and a low roll-off of 6.0%. This work also shows a strategy for designing AIE-TADF molecules by rational use of steric hindrance and weak inter/intramolecular interactions to realize high ΦPL values, fast reverse intersystem crossing process, and reduced nonradiative transition process properties, which may open the way toward highly efficient and small-efficiency roll-off devices.

Water‐Induced Blue‐Green Variable Nonconventional Ultralong Room Temperature Phosphorescence from Cross‐Linked Copolymers via Click Chemistry

AbstractUltralong room temperature phosphorescence is employed in information encryption, chemical sensing, lighting, and imaging on account of its long lifetime and high signal‐to‐noise ratio. As the triplet excitons can be easily quenched and interfered by nonradiative transition process, it is difficult to obtain long‐lived phosphorescence through conventional methods. Herein, a general design strategy to form cross‐linked networks by click chemistry is presented for efficiently promoting the phosphorescence performance. Using the hydrogen bonding interactions formed between CO···HN units and covalently cross‐linked network by the BO bond, the rigidity of the entire system is greatly enhanced, so the radiative transition process is well strengthened. Interestingly, under the influence of water molecule, the afterglow colors of the system change from blue (488 nm) to green (510 nm). Because of the presence of cross‐linked network, the emission is not directly quenched when the system is intervened by water. Having long phosphorescence lifetime (841.06 ms) and high quantum yield (10.48%), the obtained system is utilized for anti‐counterfeiting demonstration. This strategy paves a new way for the design of amorphous ultralong room temperature phosphorescence materials by efficient and user‐friendly click chemistry.

Broadband, Enhanced, and Antithermally Quenched Near-Infrared Phosphors via a Cosubstitution Approach

Wearable biosensing and food safety inspection devices with high thermal stability, high brightness, and broad near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) could accelerate the next-generation NIR light applications. In this work, NIR La3-xGdxGa5GeO14:Cr3+ (x = 0 to 1.5) phosphors were successfully fabricated by a high-temperature solid-state method. Here, by doping Gd3+ ions into the La3+ sites in the La3Ga5GeO14 matrix, a 7.9-fold increase in the photoluminescence (PL) intensity of the Cr3+ ions, as well as a remarkably broadened full width at half-maximum (FWHM) of the corresponding PL spectra, is achieved. The enhancements in the PL, PLE intensity, and FWHM are attributed to the suppression of the nonradiative transition process of Cr3+ when Gd3+ ions are doped into the host, which can be demonstrated by the decay curves. Moreover, the La1.5Gd1.5Ga5GeO14:Cr3+ phosphor displays an abnormally negative thermal phenomenon that the integral PL intensity reaches 131% of the initial intensity when the ambient temperature increases to 160 °C. Finally, the broadband NIR pc-LED was fabricated based on the as-explored La1.5Gd1.5Ga5GeO14:Cr3+ phosphors combined with a 460 nm chip, and the potential applications for the broadband NIR pc-LEDs were discussed in detail.

Rare Earth-Doped Microfiber Bragg Grating Refractive Index Sensor With Self-Photothermal Manipulation

We demonstrate a microfiber Bragg grating as the reflective refractometer with the function of self-photoheating. The rare earth-doped fiber provides not only the photosensitivity to the UV modulation but also the effective pump laser absorption and photoheating conversion. The rare earth-doped microfiber Bragg grating, which is cladding-removed by the hydrofluoric acid, can detect the tiny refractive index change with a resolution of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> RIU scale. The self-photoheating could be realized by 980 nm pump absorption and non-radiative transition process of the ytterbium and erbium ions, which are well-preserved by the core structure after etching. Monitored by the reflective grating signal, the photoheating can manipulate 30 °C increase of the device in the air, 8 °C in the ethanol, and 4 °C in the water. The second time-scale heating/cooling response allows the sensor to act as ad optical switch for engineering temperature. The work may open a new route for accelerative biosensing and pollutant determination and treatment.

Twisted Intramolecular Charge Transfer—Aggregation-Induced Emission Fluorogen with Polymer Encapsulation-Enhanced Near-Infrared Emission for Bioimaging

Fluorescence probes with strong near-infrared (NIR) emission and water solubility are considered useful visualization tools for localization marking as well as investigating cell migration and tran...