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High blood glucose levels can cause diabetes, which in turn leads to various diseases, such as cardiovascular and cerebrovascular diseases, so monitoring of blood glucose levels is urgent. Here, we report persistent luminescent nanoparticles (PLNPs), Zn1.1Cu0.001In0.0009Ga1.8Ge0.1O4 (ZCIGG), to avoid interference from background fluorescence in conventional optical sensing, surface-loaded with MnO2 nanozymes for bimodal glucose detection. The two detection modes are validated with each other and are suitable for a wide range of situations. To this end, ZCIGG was prepared with afterglow emission at 500 nm and then integrated with MnO2 nanosheets through a dissolved oxygen strategy. MnO2 shows broad absorption and quenches the phosphorescence of ZCIGG. MnO2 acts as a peroxidase-like enzyme to catalyze an H2O2-tetramethylbenzidine (TMB) reaction for the colorimetric detection of glucose, in the presence of glucose oxidase (GOx); MnO2 also acts as an oxidase to catalyze the oxidation of H2O2 to produce Mn2+ and recover afterglow emission for the phosphorescent detection of glucose. Density functional theory and microscopic kinetic modelling provide a theoretical analysis of the catalytic mechanism of MnO2 nanozymes for dual-modality detection. We also developed a mobile-phone-based intelligent analysis platform using the Python algorithm for the convenient on-site colorimetric and phosphorescent dual-detection of glucose. [ABSTRACT FROM AUTHOR]

Copper in vegetables can enter the human body, and excessive copper may cause uncomfortable symptoms; thus, it is urgent to test copper ions for safety concerns. Herein, we prepared Zn2GeO4:Mn2+,In3+ (ZGO:Mn,In) persistent luminescent nanoparticles (PLNPs) and then grafted glutathione for the determination of copper ions. ZGO:Mn,In was prepared by doping In3+ in ZGO:Mn to improve the emission at 532 nm under excitation at 258 nm. The doping amount, temperature, time, and pH were carefully optimized for a stronger emission intensity than ZGO:Mn. The fractional densities and energy band gaps were calculated by density functional theory, revealing the excitation enhancement mechanism of ZGO:Mn,In. The surface of ZGO:Mn,In was modified with carboxyl groups for linking glutathione to specially identify Cu2+ ions. The identification resulted in the aggregation-induced quenching of PLNPs' emission. Thus, the sensor exhibited good selectivity for copper ions, and the composite was successfully applied to the detection of copper ions in serum and vegetable samples. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) persistent luminescence nanoparticles (PLNPs) showed great potential for bioimaging due to their integration of non-in situ excitation and deep tissue penetration. However, PLNPs are often introduced with Cr3+ ions as the NIR emission centers. Herein, we report Cr-free Bi2Ga3.985O9:1.5% Fe3+ (BGF), with Fe3+ ions as the NIR emission centers. BGF under 310 nm excitation exhibited NIR afterglow emission at 794 nm in the first biological imaging window (650–950 nm), with the afterglow duration of 3 h. BGF was grafted with hydroxyl groups and then polydopamine (PDA) for the integration of indocyanine green (ICG) through π–π stacking and hydrophobic interactions, as the PLNP–PDA–ICG composite. Bi in the composite, as a heavy atom element, exhibits computed tomography (CT) contrast capacity, while PDA is a photothermal agent, and ICG is excited to produce reactive oxide species for photodynamic therapy. The afterglow/CT dual-modality imaging-guided photothermal/photodynamic combination therapy was validated with in vitro/vivo imaging and therapeutic applications. This work provides the Cr-free PLNP composite for drug-free theranostics with a low toxicity. [ABSTRACT FROM AUTHOR]

Herein, we designed and prepared the persistent luminescence nanoparticles (PLNPs) of γ-Ga2O3:Cr,Ba rationally with Cr ions to achieve the near-infrared (NIR) emission at 700 nm and Ba ions to improve the emission intensity by inducing trap distribution. Energy transfer between γ-Ga2O3 and Cr ions occurs as the emission at 508 nm decreases and that at 700 nm increases along with the increased content of Cr ions. In combination with the trap depth, band gap of the host, and energy levels of Cr ions, an emission mechanism was proposed. Thus, NIR emission (700 nm), high brightness, large Stokes shift (446 nm), and long afterglow time (90 min) were achieved with the optimal γ-Ga2O3:0.0025Cr,0.0012Ba (γGCB) under excitation at 254 nm. The emission intensity of γGCB is temperature-dependent for non-contact ratiometric temperature sensing, and temperature linearity ranging from 300 to 420 K was achieved with an absolute sensitivity of 3.4% K−1. γGCB and γ-G2O3 are white under sunlight but exhibit red and green emissions under single excitation at 254 nm. Thus, Morse and binary codes are adapted to achieve encryption information transfer with the combination of γGCB and γ-G2O3. This work provides ideas for selecting a host, emission center, and trap for PLNPs with desirable properties and thus achieves extensive applications, as validated with ratiometric temperature sensing and encryption information transfer. [ABSTRACT FROM AUTHOR]

The introduction of co‐dopants is one of the effective ways to improve the luminescence properties of the persistent luminescence nanoparticles (PLNPs). Herein, Cr3+, Ca2+ co‐doped and Cr3+, Ca2+, Pr3+ tri‐doped β‐Ga2O3 PLNPs with enhanced persistent luminescence were developed via the hydrothermal synthesis and subsequent calcinations, which improved the persistent luminescence of the β‐Ga2O3 PLNPs. The results showed that the prepared PLNPs had a long afterglow time of more than 8 days with a signal‐to‐noise ratio (SNR) of 272 and the Quantum yield (QY) up to 74.8 %, which was renewable by LED lamps and stored information under a high‐temperature environment. The synthesized β‐Ga2O3:Cr3+, Ca2+, Pr3+ PLNPs with long afterglow time showed great potentials in optical storage. [ABSTRACT FROM AUTHOR]