Super-long Persistent Luminescence Research Articles

A narrowband ultraviolet-B-emitting LiCaPO4:Gd3+ phosphor with super-long persistent luminescence for over 100 h

Intense NB-UVB emission at 312 nm and super-long persistent luminescence for >100 h have been realized in a LiCaPO4:Gd3+ phosphor after ceasing X-ray excitation, accompanied by a remarkable white-to-brown photochromism phenomenon.

Dynamics of Charges in Superlong Blacklight-Emitting CaB2O4:Ce3+ Persistent Phosphor

The optical and persistent luminescence properties of CaB2O4:Ce3+ phosphor are presented. The optical emission for excitation in the 250–340 nm wavelength region is dominated by two bands at 365 and 460 nm. Lifetime measurements suggested that the 365 nm emission band is due to interconfigurational Ce3+ 5d → 4f transitions. Upon excitation with a 254 nm UV lamp, a superlong persistent luminescence in the UVA1 region (340–400 nm, blacklight) was observed, lasting for at least 15 h, and with excellent reproducibility, which is perfectly suitable for phototherapy application. The initial-rise method was applied on the thermoluminescence glow curves to determine the trap distribution and trap depth. The results suggest that one distinct trap, with an activation energy of ∼0.52 eV, was solely responsible for the persistent luminescence in the CaB2O4:Ce3+ phosphor. The other traps had a quasi-continuous distribution, with activation energies between 0.56 and 1.15 eV. The proposed persistent luminescence and the...

Detection of Cell Viability via Fluorescence Labeling of Silicate Phosphor with a Low-Temperature Superlong Persistent Luminescence

Cell viability detection is usually accompanied by large errors and toxicity. For the accuracy and safety of detection, it is urgent to develop a practical approach to realize the real-time monitoring of cell viability. Here, a low-temperature persistent phosphor was employed to facilitate the detection of cell viability. Stable low-temperature persistent luminescence originating from Ba4Si6O16:Eu2+, Pr3+ (BSEP) was developed, which could be quantified to describe the viability of baby Syrian hamster kidney (BHK-21) cells. The defect state structure guarantees the excellent persistent luminescence at 193 K of more than 200 h of the as-prepared BSEP phosphor, which ensures the long-term biological application. The structural thermal stability and water tolerance of BSEP suggest the feasibility of the practical application. Our results provide the underlying insights of the low-temperature persistent phosphors for real-time biological detection.

A strategy for developing thermal-quenching-resistant emission and super-long persistent luminescence in BaGa2O4:Bi3+

A novel BaGa2O4:0.02Bi3+ phosphor with excellent thermal-quenching-resistant emission and super-long persistent luminescence has been synthesized and systematically investigated.

Positive effect of codoping Yb3+ on the super-long persistent luminescence of Cr3+-doped zinc aluminum germanate

A series of novel near-infrared (NIR) long persistent phosphors of Zn1.2Al1.6Ge0.2O4: Cr3+, Yb3+ was synthesized by a solid state method. The crystal structure of Zn1.2Al1.6Ge0.2O4 was identified. Yb3+ ions were effective codopants for improving the NIR persistent luminescence intensity even after 100 h of decay. The persistent luminescence decay curves and the thermo-luminescence spectra were analyzed. Results indicated that the increase in efficient electron trap concentration induced by doping Yb3+ ions was a major factor in the improvement of the NIR persistent luminescence. Moreover, short-wave infrared (SWIR = 900–1700 nm) emission of Yb3+ was be excited by UV and visible light through charge transfer transition of O2-–Yb3+ and energy transfer from Cr3+ to Yb3+, respectively.

Formation of Deep Electron Traps by Yb3+ Codoping Leads to Super-Long Persistent Luminescence in Ce3+-Doped Yttrium Aluminum Gallium Garnet Phosphors.

The Y3Al2Ga3O12:Ce3+-Cr3+ compound is one of the brightest persistent phosphors, but its persistent luminescence duration is not so long because of the relatively shallow Cr3+ electron trap. To compare the vacuum referred binding energy of the electron trapping state by Cr3+ and lanthanide ions, we selected Yb3+ as a deeper electron trapping center. The Y3Al2Ga3O12:Ce3+-Yb3+ phosphors show Ce3+:5d → 4f green persistent luminescence after blue light excitation. The formation of Yb2+ was confirmed by the increased intensity of absorption due to Yb2+:4f-5d at 585 nm during the charging process. This result indicates that the Yb3+ ions act as electron traps by capturing an electron. From the thermoluminescence glow curves, it was found that the Yb3+ trap makes a much deeper electron trap with a 1.01 eV depth than the Cr3+ electron trap with a 0.81 eV depth. This deeper Yb3+ trap provides a much slower detrapping rate of filled electron traps than the Cr3+-codoped persistent phosphor. In addition, by preparing transparent ceramics and optimizing Ce3+ and Yb3+ concentrations, the Y3Al2Ga3O12:Ce3+(0.2%)-Yb3+(0.1%) as-made transparent ceramic phosphor showed super-long persistent luminescence for over 138.8 h after blue light charging.

Erythrocyte membrane bioinspired near-infrared persistent luminescence nanocarriers for in vivo long-circulating bioimaging and drug delivery

Combination of biological entities with functional nanostructure would produce the excellent systemic drug-delivery vehicles that possess the ability to cross the biological barriers. Herein, from a biomimetic point of view, erythrocyte membrane bioinspired optical nanocarrier is fabricated by integrating Red blood cell (RBC) membrane vesicle with near-infrared persistent luminescence nanophosphors (PLNPs). The triple-doped zinc gallogermanate nanostructures with super-long near-infrared persistent luminescence (ZGGO) are used as optical emission center, mesoporous silica coated on the PLNPs (ZGGO@mSiO2) is employed for drug delivery, and the RBC membrane vesicle is introduced for biomimetic functionalization to ensure the developed nanocarriers bypass macrophage uptake and systemic clearance. Owing to the coating of natural erythrocyte membrane along with membrane lipids and associated membrane proteins, the proposed bioinspired nanocarriers have exhibited cell-mimicking property. Retaining the applicability of PLNPs core that favored in vitro excitation, the developed RBC-ZGGO@mSiO2 biomimetic nanocarriers have demonstrated intense fluorescence, super-long persistent luminescence, monodispersed nanosize, red light renewability, and excellent biocompatibility. In vivo mice bioimaging and biodistribution study demonstrate the erythrocyte membrane bioinspired nanoprobe loaded with doxorubicin as ideal nanocarriers for long-circulating bioimaging, in situ real-time monitoring and drug delivery. We believe the PLNPs-based biomimetic nanocarriers offer a promising nano-platform for diagnostics and therapeutics application.

Gadolinium Complexes Functionalized Persistent Luminescent Nanoparticles as a Multimodal Probe for Near-Infrared Luminescence and Magnetic Resonance Imaging in Vivo

The development of multimodal nanoprobes that combined properties of near-infrared (NIR) fluorescence and magnetic resonance imaging (MRI) within a single probe is very important for medical diagnosis. The NIR-emitting persistent luminescent nanoparticles (PLNPs) are ideal for optical imaging owing to no need for in situ excitation, the absence of background noise, and deep tissue penetration. However, no PLNP based multimodal nanoprobes have been reported so far. Here, we report a novel multimodal nanoprobe based on the gadolinium complexes functionalized PLNPs (Gd(III)-PLNPs) for in vivo MRI and NIR luminescence imaging. The Gd(III)-PLNPs not only exhibit a relatively higher longitudinal relaxivity over the commercial Gd(III)-diethylenetriamine pentaacetic acid complexes but also keep the superlong persistent luminescence. The prepared Gd(III)-PLNPs multimodal nanoprobe offers great potential for MRI/optical imaging in vivo.