Deep Red Emission Research Articles

Early Diagnosis of Tumorigenesis via Ratiometric Carbon Dots with Deep-Red Emissive Fluorescence Based on NAD+ Dependence

The early diagnosis of tumorigenesis is crucial for clinical treatment, but the resolution and sensitivity of conventional short-wavelength biomarkers are not ideal because of the complicated interference in living tissue. Herein, a nicotinamide adenine dinucleotide (NAD+)-responsive probe with deep-red emissive ratiometric fluorescence was synthetized as a promising target for energy metabolism patterns during tumorigenesis. Interestingly, the solvents H3PO4 and 2,2′-dithiodibenzoic acid enhanced the red emission (640 and 680 nm) of o-phenylenediamine-based carbon dots (CDs), leading to the formation of a nanoscale graphite-like skeleton covered with -P=O, -CONH-, -COOH and -NH2 on their surfaces. Meanwhile, this method exhibited high sensitivity to the discriminating target NAD+, with a detection limit of 63 μM due to the inner filter effect and fluorescence resonance energy transfer process between NAD+ and CDs, which is superior to the reported capillary electrophoresis and liquid chromatographic detection methods (the reported detection limit was about 0.2 mM) in complex biological samples and even cancer cells. Encouragingly, NAD+ significantly promoted nucleus-targeting fluorescence and cell migration compared to GSH and pH stimulation, which were gradually eliminated in human hepatocellular carcinoma (HepG2) cells after 2-deoxy-d-Glucose inhibited the glycolytic phenotype. The proposed method holds great potential for the temporal and spatial resolution of NAD+-dependent tumor diagnosis in complex living systems.

Strong emission and plant-growth effects of inversion symmetry lowered Mn4+ on Ca2+, Ga3+ and P5+ substituted SrAl12O19: Mn4+

The high-temperature solid-phase method was used to synthesize the co-solid phosphor (Sr, Ca) (Al, P)12O19: Mn4+, Mg2+, Ga3+. Previous studies have already observed that the doping of Ca2+ for Sr2+ site and Ga3+ for Al3+ site enhances the luminescence intensity of SrAl12O19: Mn4+. Here, we observed that the unique doping of P5+ for Al3+ significantly enhances the luminescence intensity. However, it is never known why these cations can enhance the luminescence. We analyzed Mn K-edge pre-edge peak of XANES and EXAFS and conducted Rietveld analyses of XRD. Then, we reached a comprehensive trend that in all cases, the substitution of cation having significantly larger covalency elongates nearby Mn4+/Al3+–O2- bond and shrink Mn4+/Al3+–O2- bond in opposite side in (Mn4+, Al3+)O6 octahedron, significantly lowering inversion symmetry and lowering parity forbidden transition of 1 s → 3d (pre-edge peak) and 3d → 3d (deep red emission) common as a transition of even parity → even parity. Such a deep red phosphor receiving multiple doping had high external quantum efficiency, 53 %, which much increased the yield of lettuce (+40 %) and mini-tomato (+49 %), which is world-top increase for the important growth of tomato series, compared with the growth (+20 %) under the conventional greenhouse-type sunlight converter.

Highly and Deep Red-Luminescent Bisphenylamine-Appended Benzocarcogendiazole Fluorophores.

Benzocarcogendiazole units have been frequently utilized for optoelectronics such as organic solar cells because of their robustness, rigidity, and band-gap tunability based on their strong electron-withdrawing properties. Focusing on the luminescent characteristics, these molecules have been utilized to demonstrate highly sensitive chromisms because of the potential of charge transfer. Here, we demonstrate deep red-emissions in bis(4-tert-butylphenyl)amine-appended benzocarcogendiazole-based donor-acceptor-donor (D-A-D) fluorophores, namely 1 and 2. Because benzocarcogendiazole and bis(4-tert-butylphenyl)amine serve as strong electron acceptor and donor, respectively, strong intramolecular charge transfer (ICT) enables long wavelength of photoluminescence (PL) even in the small molecular weight. Although photoluminescence (PL) in long wavelength tends to exhibit quite low absolute PL quantum efficiency (ΦPL), the values of solutions 1 and 2 are quite high (up to 50 %). According to X-ray crystallographic characterizations and DFT calculations, these high ΦPL values are attributable to the segregated π-planes of benzocarcogendiazole units, which is induced by the bulky substituents of bis(4-tert-butylphenyl)amines.

A New Organic Laser Material Design Toward Ultra-Low Amplified Spontaneous Red Emission and Ultra-Bright Electroluminescence.

Significant efforts are dedicated to developing new classes of organic semiconductor materials to achieve electrically pumped lasing. However, further advancements are necessary to understand the relationship between the structure and property for the creation of innovative laser materials with high stability, low triplet yield, ultra-low lasing threshold, and low-efficiency roll-off at ultra-bright electroluminescence. Here, a new design principle is validated for organic semiconductor laser materials, demonstrating simultaneous enhancement in the key figures of merit of low amplified spontaneous emission thresholds (Eth), efficient electroluminescence, and low triplet yields. By applying the Einstein stimulated emission rate equation and Strickler-Berg approximation, Two red-emitting laser dimers of Cibalackrot with different linkers are constructed, leading to giant enhancement (≈250%) in oscillator strengths, and stimulated emission cross-sections. When blended in poly(9,9-dioctylfluorene-alt-benzothiadiazole), the new dimers achieve an ultra-low Eth (4.5±0.3µJcm-2) in the deep red region (λASE=655nm), among the lowest reported for deep-red emitters. Organic light-emitting diodes (OLEDs) utilizing the dimer blend exhibit low-efficiency roll-off under DC mode. Under pulse operation, the OLEDs achieve high current densities (90Am-2) and ultrahigh brightness (≈710000cdm-2). These findings highlight the dimerization design as an excellent platform to advance organic semiconductor laser materials.

Phosphorescent cyclometalated Ir(III) complexes with fluoranthene unit and their near-infrared (NIR) OLEDs showing NIR% higher than 99 %

With the aim to design and synthesize cyclometalated Ir(III) complexes with near-infrared (NIR) emission, a series of ppy-type ligands with fluoranthene unit have been synthesized bearing different aromatic nitrogen heterocycles of isoquinoline, quinoline, pyridine and benzo [d]thiazole. With these organic ligands, four [Ir (ppy)2 (acac)] complexes are prepared named as IrFTIQ, IrFTQL, IrFTPY and IrFTBZ. In solution, IrFTIQ can emit NIR phosphorescence at 738 nm, while IrFTQL (ca. 692 nm), IrFTPY (ca. 670 nm) and IrFTBZ (ca. 690 nm) are typical deep-red emitters. It should be noted that all these fluoranthene-based cyclometalated Ir(III) complexes show good electrochemical stability indicated by their reversible redox procedures. When doped in the emission layer of OLEDs, IrFTIQ and IrFTBZ can furnish NIR electroluminescence (EL) at 748 nm and 700 nm, respectively, while the devices with IrFTPY as emitter can furnish deep-red EL. Critically, the optimized OLED doped with IrFTIQ can achieve maximum external quantum efficiency (EQE) as high as 5.01 % and a radiance up to 6284 mW Sr−1 m−2. Critically, the NIR OLEDs based on IrFTIQ can furnish EL with NIR component (NIR%) of a total spectrum > 99 %. All these encouraging results definitely demonstrate the effectiveness of our molecular design strategy for the new-type Ir(III) NIR phosphorescent complexes and the great potential of the fluoranthene group in developing high-performance Ir-based NIR phosphors for OLEDs.

High EQE of 43.76% in solution-processed OLEDs operating at a wavelength of 626 nm

Simultaneously achieving high-efficiency, deep-red emission, and solution-processed organic light-emitting diodes (OLEDs) remains a huge challenge. In this work, a thermally activated delayed fluorescent (TADF) material of CzPXZ that exhibits aggregation-induced emission property and a deep-red phosphorescent emitter of Ir(dmppy)(piq)2(od) are developed to build effective energy transfer pathways by dissolving them in a non-polar organic solvent. The electroluminescent emission peaks of CzPXZ:Ir(III)-based OLEDs are located at deep-red 626 nm, demonstrating efficient energy transfer from CzPXZ to the Ir(III) complex. Furthermore, an optimized DPEPO hole-blocking layer is utilized in such Ir(III)-doped OLEDs to enhance the radiative recombination. Therefore, a high external quantum efficiency of 43.76% is achieved for CzPXZ:Ir(III)-based OLEDs. This work sheds light on the great potential of energy transfer from AIE-TADF to red phosphorescent emitters for high-efficiency, solution-processed, deep-red OLEDs.

Achieving deep red to near-infrared emission in dinuclear platinum (II) complexes with the donor-π-acceptor-type cyclometalated ligand

A novel deep red-emitting dinuclear platinum (II) complex, (TPA2niq)2Pt2(C8OXT)2, featuring a donor-π-acceptor (D-π-A) type ligand, was synthesized and characterized. Here, TPA2niq represents the 4-(tert-butyl)-N-(4-(tert-butyl)phenyl)-N-(4-(6-(isoquinolin-1-yl)naphthalen-2-yl)phenyl)aniline unit, while C8OXT was the abbreviation for the bridging ligand 5-(4-octyloxyphenyl)-1,3,4-oxadiazole-2-thiol. Its photophysical, electrochemical, and electroluminescent characteristics were primarily studied. It was found that (TPA2niq)2Pt2(C8OXT)2 exhibited a saturated deep red emission with a peak at 686 nm in dichloromethane. Furthermore, the (TPA2niq)2Pt2(C8OXT)2-doped polymer electroluminescent devices (PLEDs), fabricated through a solution process, exhibited outstanding electroluminescence (EL) properties, with an emission peak at 684 nm, a maximum external quantum efficiency (EQE) of 3.78%, and a maximum radiant emittance of 4478 mW/Sr/m2. By incorporating the D-π-A type ligand into the dinuclear platinum (II) complex, the PLEDs achieved efficient deep red emission.

High‐Efficiency Deep Red Fluorescent Material with Aggregation Induced Emission and the Application in Organic Light‐Emitting Diodes

AbstractThe development of highly efficient deep red materials with emission wavelength beyond 650 nm remains a big challenge due to the constraints imposed by the energy gap rule. In this work, a donor‐acceptor‐donor type emitter, 4,7‐bis (10‐(4‐(tert‐butyl) phenyl)‐10H‐phenothiazin‐3‐yl) benzo[c][1,2,5] thiadiazole (TBPPTZ) is designed and synthesized. Resulting from the slight twist angle between the donor and acceptor units, TBPPTZ exhibits nearly planar conformation and an extended conjugated structure. TBPPTZ shows a deep red emission peak at 687 nm and aggregation induced emission property with a high photoluminescence quantum yield of 45 % in neat thin film. The optimized organic light‐emitting diode (OLEDs) utilizing TBPPTZ as the non‐doped emissive layer obtains a high external quantum efficiency (EQE) up to 2.51 % with an electroluminescence (EL) peak at 676 nm, aligning with the Commission Internationale de L'Eclairage (CIE) coordinates (0.68, 0.31), which shows a small EQE roll‐off of only 5.6 % at 100 cd m−2. Additionally, the doped OLED achieves an EQE up to 5.09 %, with an EL peak at 656 nm and CIE coordinates of (0.65, 0.34). The findings of this research not only contribute to achieve highly efficient deep red OLEDs but also offer a novel and effective deep red molecular strategy to realize high‐quality OLEDs.

Enhanced luminescence performance in double perovskite CaSrLaSbO6: Mn4+ red emission phosphors for indoor plant growth via cation doping

Novel CaSrLaSbO6: Mn4+ red-emitting phosphors with double perovskite structure were successfully synthesized by the high-temperature solid-phase method. CaSrLaSbO6:Mn4+ phosphor showed a broad excitation band with different excitation peaks from 250 nm to 600 nm owing to the Mn4+-O2- charge transfer and 4A2g → (4T1g, 2T2g, and 4T2g) transitions of Mn4+ ions and exhibited intense deep-red emission at 678 nm attributed to the 2Eg → 4A2g transition of Mn4+ ions. To further enhance the performance of the phosphor, a cation doping method was adopted in this paper to synthesize CaSrLa1-xLnxSbO6: Mn4+ (Ln = Gd, Y) phosphors. The luminescence intensity of the samples was enhanced after doping with different cations, and the related mechanism was discussed. In addition, the microstructure and crystal field environment were systematically investigated. The luminescence intensity of the CaSrLa0.85Y0.15SbO6: Mn4+ phosphor was about 1.82 times higher than that of CaSrLaSbO6: Mn4+phosphor. The emission spectrum of the sample matched well with the absorption band of plant pigments. Furthermore, the plant growth LEDs and light-conversion film were prepared by using the optimized CaSrLa0.85Y0.15SbO6: Mn4+. The results indicate that the designed phosphors have great potential applications in agricultural cultivation.

Carbon dots as a distinctive platform fabricated through a sustainable approach for versatile applications

Red-emitting carbon dots (R-CDs) have garnered significant interest owing to its exceptional fluorescence (FL) characteristics. In this study, we present a one-pot solvothermal synthesis for producing biomass-derived R-CDs, utilizing Birch leaves as the primary raw material. The R-CDs display high solubility in ethanol and demonstrate deep-red emission at 625 nm with narrowband characteristics. After conducting a selectivity assessment with different metal ions, it is observed that R-CDs demonstrate exceptional sensitivity and specificity specifically to Fe3+. This demonstrates a linear relationship up to a concentration of 500 μM, with a detection limit of 0.302 μM (S/N=3). In this research, we created photoluminescent and transparent composites made from polyvinyl alcohol (PVA) with embedded fluorescent R-CDs, using the solution casting method for fabrication. The synthesized R-CDs exhibit robust and consistent FL in solution, whereas, the R-CDs@PVA nanocomposites (NCs) films are transparent and exceptionally flexible. The optimized 0.08 wt% R-CDs demonstrated the most effective ultra violet (UV) blockage across the UV-A (76.84 %), UV-B (74.86 %), and UV-C (78.46 %) region. However, PVA alone absorbed < 25 % of the light in all UV regions. The study explored the shape memory and FL characteristics of the R-CDs@PVA NCs changed under varying conditions such as water, temperature and pH. In alkaline conditions, the FL intensity of the R-CDs@PVA NCs increased due to the deprotonation of the R-CDs surface. In addition, R-CDs dispersed within PVA exhibit superior ink-free patterned substrates, proving to be advantageous for non-destructive template relief printing. Furthermore, R-CDs serve as effective anti-oxidants, combating 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and mitigating the oxidative stress (OS) in red blood cells (RBCs) induced by sodium nitrite (NaNO2). They aid in the restoration of essential stress indicators, encompassing lipid peroxidation (LPO), protein carbonyl content (PCC), total thiol (TT), superoxide dismutase (SOD), and catalase (CAT). Furthermore, R-CDs restored the damaged liver, kidney, heart, and pancreas by regulating biochemical parameters. Furthermore, incorporated R-CDs into red light-emitting diodes (R-LEDs) and white light-emitting diodes (W-LEDs), thereby enhancing plant growth efficiency. The results of this study highlight the possible of R-CDs as non-toxic, UV blocking agents suitable for developing edible coatings and packaging. These properties suggest their applicability in the food industry, anti-counterfeiting (AC) measures, and biomedical applications.

Excited-State Dynamics of a Bright Fluorescent Dye with Precise Control of Emission Color Using Acid-Base Equilibrium, Intramolecular Charge Transfer, and Host-Guest Chemistry.

A fluorescent dye, a dithiophene-conjugated benzothiazole derivative (DTBz), was prepared to have high fluorescence emission quantum yields (ΦF) across various organic solvents. Its emission color modulation, from bright blue to deep red, was achieved through intramolecular charge transfer (ICT), acid-base equilibrium, and host-guest chemistry. Although it exhibits a weak solvatochromic effect, DTBz exhibited a bright fluorescence emission around 480 nm upon excitation at 390 nm in most solvents. In polar solvents, such as MeOH (methanol), EtOH (ethanol), DMF (N,N-dimethylforamide), and DMSO (dimethyl sulfoxide), an additional ICT emission band emerged around 640 nm, notably intense in DMSO, resulting in a bright greenish-white emission (ΦF = 0.67). The addition of 1,8-diazabicyclo[5,4.0]undec-7-ene (DBU) altered emission characteristics, reducing emission from the local excited (LE) state and enhancing ICT state emission. The degree of emission spectral change saturation with DBU addition varied with the solvent nature. Polar solvents with high dielectric constants, like DMSO and DMF, saw a complete disappearance of LE state emission with 5 equiv of DBU, resulting in a deep red emission (ΦFs of 0.53 and 0.48, respectively). Femtosecond transient absorption spectroscopy and time-resolved photoluminescence measurements elucidated the excited-state dynamics, revealing a long-lived excited state (τ-H = 10.3 ns) at a lower energy emission (640 nm), identified as DTBz-*, supported by transient absorption spectra analysis. Further analysis, including time-resolved fluorescence decay measurements and time-dependent density-functional theory (TD-DFT) calculations, underscored the role of deprotonation of DTBz's hydroxyl group in promoting the ICT process. The CIE coordination plot demonstrated wide linear emission color changes upon successive DBU additions in all solvents, while emission color precision was achieved through host-guest chemistry. Emission changes induced by DBU were reverted to the original state upon beta-cyclodextrin (β-CD) addition, with the 1H NMR study revealing the competition between acid-base equilibrium and host-guest complex formation as the cause of emission color change.

Using Principal Component Analysis for Temperature Readings from YF3:Pr3+ Luminescence

The method of measuring temperature using luminescence by analyzing the emission spectra of Pr3+-doped YF3 using principal component analysis is presented. The Pr3+-doped YF3 is synthesized using a solid-state technique, and its single-phase orthorhombic crystal structure is confirmed using X-ray diffraction. The emission spectra measured within the 93–473 K temperature range displays characteristic Pr3+ f-f electronic transitions. The red emission from the 3P0,1→3H6,3F2 electronic transition mostly dominates the spectra. However, at low temperatures, the intensity of the green emissions from the 3P0,1→3H5, deep-red 3P0,1→3F4, and the deep-red emissions from the 3P0,1→3F4 transitions are considerably lower compared to the intensity of the red emissions. Temperature variations directly impact the photoluminescent spectra, causing a notable increase in the green and deep-red emissions from the 3P1 excited state. We utilized the entire spectrum as an input for principal component analysis, considering each temperature as an independent group of data. The first principal component explained 99.3% of the variance in emission spectra caused by temperature and we further used it as a reliable temperature indicator for luminescence thermometry. The approach has a maximum absolute sensitivity of around 0.012 K−1. The average accuracy and precision values are 0.7 K and 0.5 K, respectively.

Promising deep-red emitting Cr3+-doped SrAl12O19 phosphors for plant growth LEDs.

Recently, deep-red-emitting phosphors that can be excited by ultraviolet (UV) and near-ultraviolet (NUV) light have been extensively investigated for plant growth LED applications. However, due to the harmful effects of these high-energy rays on plants, violet- or blue-excited deep-red-emitting phosphors are considered a more appropriate solution. In this work, SrAl12O19:Cr3+ phosphors were synthesized using a simple solid-state reaction, revealing a strikingly sharp deep-red emission band centered at 694 nm and effective excitation by violet light. The optimal SrAl12O19:1.0%Cr3+ phosphor, annealed at 1500°C, exhibits an extended lifetime of 0.549 ms, an energy activation level of 0.239 eV, a good quantum efficiency (QE) of 36.2%, and superior color purity at 100%. Further, an LED prototype with a precise absorption spectrum for far-red phytochrome (Pfr) has been demonstrated. These results indicate that the synthesized SrAl12O19:1.0%Cr3+ phosphors could be used as a promising deep-red-emitting phosphor for plant growth LED.

Water-Soluble Alumina-Coated Indium Phosphide Core-Shell Quantum Dots with Efficient Deep-Red Emission Beyond 700nm.

Solution-processed colloidal III-V semiconductor-based quantum dots (QDs) represent promising and environmentally-friendly alternatives to Cd-based QDs in the realms of optoelectronics and biological applications. While InP-based core-shell QDs have demonstrated efficientlight-emitting diode (LED) performance in the visible region, achieving deep-red emission (above 700nm) with a narrow linewidth has proven challenging. Herein, the study presents a novel strategy for synthesizing InP/ZnSe/ZnS core-shell-shell QDs tailored for emission in the first biological transparency window. The resulting QDs exhibit an emission wavelength up to 725nm with a narrow peak full width at half maximum (FWHM) down to 107 meV (45nm). To enhance the biocompatibility and chemical stability of the QDs, their surface is further capped with a layer of amorphous alumina resulting in an InP/ZnSe/ZnS/Al2O3 heterostructure. This surface passivation not only ensures environmental- and photostability but also enhances the photoluminescence quantum yield (PLQY). The alumina capping enables the aqueous phase transfer via surface ligand exchange using mercaptopropionic acid (MPA) while maintaining the initial quantum yield. The resulting QDs demonstrate a significant potential for advancing next-generation optoelectronic technologies and bio-applications.

Three-Charge (0, -1, -2) Ligand-Based Binuclear and Mononuclear Deep-Red Phosphorescent Iridium Complexes Bearing Benzo[d]oxazole-2-Thiol Ligand.

A new class of three-charge (0, -1, -2) ligand-based binuclear and mononuclear iridium complexes bearing benzo[d]oxazole-2-thiol ligand have been synthesized. Notably, the binuclear complexes (IrIr1 and IrIr2) can be generated at low temperatures by reacting the iridium complex precursors (2a and 2b) with equal amounts of the benzo[d]oxazole-2-thiol ligands, while the corresponding mononuclear complexes (Ir1 and Ir2) are formed at high temperatures. X-ray diffraction analysis shows that the benzo[d]oxazole-2-thiol ligand plays an unusual and interesting bridging role in binuclear complexes and induces rich intermolecular and intramolecular interactions, while in mononuclear complexes, it forms an interesting four-membered ring coordination. More importantly, all complexes experienced efficient deep-red emission in the 628-674 nm range, and the mononuclear complexes have higher luminescent efficiency and longer excited state lifetime than the binuclear complexes. As a result, organic light-emitting diode devices incorporating two mononuclear complexes (Ir1 and Ir2) as guest material of the light-emitting layer can obtain good maximum external quantum efficiency (3.5% and 5.5%) in the deep-red region (629 and 632 nm) with CIE coordinates (0.61, 0.33) and (0.62, 0.34), along with a low turn-on voltage (2.8 V).

Binary Host-induced Exciplex Enabled High Color-Rendering Index of 94 for Carbon Quantum Dot-Based White Light-Emitting Diodes.

White light-emitting diodes (WLEDs) with high color-rendering index (CRI, >90) are important for backlight displays and solid-state lighting applications. Although the well-developed colloidal quantum dots (QDs) based on heavy metals such as cadmium and lead are promising candidates for WLEDs, the low CRI still remains a significant limitation. In addition, the severe toxicity of heavy metals greatly limits their widespread use. Herein, the study demonstrates low-cost and environmentally friendly carbon quantum dots (CQDs)-based WLEDs that exhibit a high CRI of 94.33, surpassing that of conventional cadmium/lead-containing QD-based WLEDs. This achievement is attained through the employment of a binary host-induced exciplex strategy. The high hole/electron mobility and suitable energy levels of the donor and acceptor give rise to a broadband orange-yellow emission stemming from the exciplex. As the host, the binary exciplex is capable of contributing blue and orange-yellow emission components while efficiently mitigating the aggregation-induced quenching of CQDs. Meanwhile, CQDs effectively address the deep-red emission gap, enabling the realization of CQDs-based WLEDs with high CRI. These WLEDs also exhibit a remarkably low turn-on voltage of 2.8V, a maximum luminance exceeding 2000cd m- 2, a correlated color temperature of 4976 K, and Commission Internationale de l'Eclairage coordinates of (0.34, 0.32).

Exploring innovative applications of Sr2MgSi2O7:Fe3+ luminescent system in surface-triggered fingerprint divergence and cheiloscopy screening

In this study, we employ a cost-effective combustion method to synthesize (1–11 mol %) Fe3+ doped Sr2MgSi2O7 nanophosphors (SMSO NPs) and conduct a comprehensive investigation into their structural and luminescent properties. The impact of iron concentration on the structural and optical characteristics is thoroughly analysed, revealing a tetragonal crystal structure with space group P-421m through Rietveld refinement and X-ray Diffraction (XRD) patterns. Scanning electron microscopy showcases the random dispersion of agglomerated particles with non-uniform dimensionality. Energy Dispersive X-ray analysis (EDS) assesses the nominal composition of Sr, Mg, Si, Fe, and O, while X-ray Photon Spectroscopy (XPS) confirms the direct incorporation of Fe3+ ions into the SMSO lattice. Photoluminescence (PL) emission spectra exhibit a deep red emission band at 718 nm. The residual luminescence intensity of SMSO:7Fe3+ at 200 °C is 91 %. Under 365 nm UV light, the optimized SMSO:7Fe3+ NPs displays easily identifiable levels I-III fingerprints (FPs) features with good resolution and contrast. The resilient luminescence and nano-regime of the phosphor reveal well-defined type I–V groove patterns in latent lip prints (LLPs) on various non-porous surfaces, unaffected by background interference or colour distraction. This study highlights SMSO:7Fe3+ NPs as a promising option for individualizing and detecting latent fingerprints (LFPs) and lip prints (LPs).

Hydroporphyrin-BODIPY arrays

Arrays composed of BODIPY and hydroporphyrin (chlorin or bacteriochlorin) components feature multiple strong absorption bands across visible and near-IR regions, efficient energy transfer from BODIPY to hydroporphyrin moiety, and strong deep-red or near-IR emission. These properties make such arrays attractive candidates for a variety of applications, particularly in solar energy conversion and biomedicine. In this review, the molecular design, synthesis, and photophysical properties of BODIPY-hydroporphyrin arrays are described. Their applications as fluorescent probes for in vivo imaging are also discussed.

Promoting NIR‐Driven Luminescence Activity of Calcium zinc galliumate via Energy Transfer from Mn4+ to Ho3+ for Second Biological Window

AbstractNIR luminescent materials are widely available for biological applications, and the NIR emitting of Ho3+ ions has received widespread attention in the second biological window. In this work, Ca14Zn6Ga10O35 : Mn4+,Ho3+ luminescent materials were synthesized using a high temperature solid state method. Optical properties and energy transfer mechanisms have studied in detail. Upon UV‐vis light excitation, the Mn single doped Ca14Zn6Ga10O35 phosphors exhibit deep red and NIR emission centered at 712 and 1151 nm assigned to Mn4+ and Mn5+, respectively. Another stronger NIR emitting peaked at 1195 nm occurs when the Ho3+ ion is co‐doped into Ca14Zn6Ga10O35 : Mn4+. The energy transfer from Mn4+ to Ho3+ ion is performed through a resonant type by a dipole‐dipole interaction mechanism. In addition, the thermal stability of Ca14Zn6Ga10O35 : Mn4+,Ho3+ phosphor has been investigated, and the NIR emission of Ho3+ ion maintains more than half the strength at 423 K. The findings indicate that the as‐prepared Ca14Zn6Ga10O35 : Mn4+,Ho3+ luminescent materials hold promise for potential applications in the second biological window.

Cationic cyclometalated platinum (II) complexes of metformin with self-assembly and AIE behavior as nuclear and mitochondrial targeted anticancer theragnostic agents

Self-assembly and AIE (Aggregation-induced emission) of cyclometalated platinum (II) complexes have attracted lots of attention. The high hydrophilia and low permeability of metformin (Met) has greatly hindered its further clinical application, herein, our work rationally designed and synthesized a pair of theragnostic cyclometalated platinum (II) - metformin complexes. Pt1 and Pt2 can improve bioactivity of Met significantly, and AIE deep-red emission can be mediated by tuning chemical structure of auxiliary ligand in compounds. Moreover, self-assembly of two Pt (II) complexes was revealed, as well as mitochondria and nuclear targeting ability of Pt2 were newly obtained during an AIE process. Meanwhile, Pt2 exhibits 186- and 53-fold enhanced antiproliferative activity compared with Met and Met-free complex analogue, their anticancer mechanisms were also investigated. Herein, our work provides a novel strategy for designing multi-functional platinum-based anticancer theragnostic agents.