Portable paper-based probe for on-site ratiometric fluorescence determination of total flavonol glycosides in plant extract using smartphone imaging.

A smartphone-assisted, paper-based ratio fluorescence probe is presented for the rapid, low-cost and on-site quantification of total flavonol glycosides in Ginkgo biloba extracts (GBE). The Al3+/Eu-MOF/paper-based probe utilizes lanthanide metal-organic framework (Ln-MOF) nanoparticles immobilized on Whatman filter paper along with Al3+ for detecting flavonols, which are the hydrolyzed products of flavonol glycosides. The color change of the paper-based fluorescence image from red to orange depends on the concentration of the target analyte in the sample solution. The smartphone equipped with a red, green, blue (RGB) color detector measured the fluorescence signal intensity on the paper substrate after adding flavonol. The analytical variables affecting the performance of the probe, including the addition sequence of the aluminum nitrate solution, its concentration, that of the Ln-MOF solution, the drying time of the paper probe, the reaction time and the sensitivity parameters of the mobile phone camera (ISO), were optimized. Under optimal conditions, the Al3+/Eu-MOF/paper-based probe has good linear response in the concentration range 7 ~ 80 µg mL- 1 and a lower detection limit of 2.07 µg mL- 1. The results obtained with the paper-based ratio fluorescence probe and smartphone combination were validated by comparing them with high-performance liquid chromatography (HPLC) measurements. This study provides a potential strategy for fabricating Al3+/Eu-MOF/paper-based probe used for total flavonol glycosides determination.

Transcriptional Regulation of Methanol Dehydrogenases in the Methanotrophic Bacterium Methylococcus capsulatus Bath by Soluble and Insoluble Lanthanides.

The effects of soluble and insoluble lanthanides on gene expression in Methylococcus capsulatus Bath were investigated. Genes for lanthanide-containing methanol dehydrogenases (XoxF-MDHs) and their calcium-containing counterparts (MxaFI-MDHs) were up- and down-regulated, respectively, by supplementation with soluble lanthanide chlorides, indicating that M. capsulatus has the "lanthanide switch" observed in other methanotrophs. Insoluble lanthanide oxides also induced the lanthanide switch and were dissolved by the spent medium of M. capsulatus, suggesting the presence of lanthanide-chelating compounds. A transcriptome ana-lysis indicated that a gene cluster for the synthesis of an enterobactin-like metal chelator contributed to the dissolution of insoluble lanthanides.

Fabrication of sodium alginate-doped carbon dot composite hydrogel and its application for La (III) adsorption and enhanced the removal of phosphorus.

Adsorption is an effective method for the removal of hazardous substances from wastewater. In this work, a low-cost and environmental-friendly composite hydrogel material of sodium alginate doped with nitrogen doped carbon dots (SA@NCDs) was fabricated by impregnation for lanthanide and enhanced phosphorus adsorption in wastewater. The effects of NCDs doping amount, dosage, pH, initial solution concentration, adsorption time and temperature on the process of La (III) adsorption by SA@NCDs were investigated. The adsorption isotherms fitted to Langmuir isotherm model (R2 = 0.9970-0.9989) and the adsorption kinetics followed pseudo-second-order kinetic model (R2 = 0.9992). The maximum adsorption capacity of the adsorbent for La (III) was 217.39 mg/g according to the Langmuir model at 298.15 K. After five cycles, the removal efficiency of La (III) adsorbed by SA@NCDs was still 85.1%. Moreover, the loaded La (III) enhanced the adsorption of phosphorus. The La (III)-SA@NCDs-5 hydrogel adsorbent greatly improved the adsorption capacity for phosphorus compared with the La (III)-free adsorbent, and the adsorption amount can reach 9.64 mg-P/g. The SA@NCDs complex hydrogels for rare earth adsorption were prepared by introducing NCDs rich in amino group into SA hydrogels. The introduction of NCDs increases the adsorption sites of hydrogels, and also overcomes the problem that NCDs itself is difficult to recover in wastewater treatment applications. The lanthanide adsorbed material has a stable structure and can be used to remove phosphorus to deal with waste using the waste. It indicates the SA@NCDs hydrogel composite adsorbent have good potential for wastewater treatment.

Sparse pseudocontact shift NMR data obtained from a non-canonical amino acid-linked lanthanide tag improves integral membrane protein structure prediction.

A single experimental method alone often fails to provide the resolution, accuracy, and coverage needed to model integral membrane proteins (IMPs). Integrating computation with experimental data is a powerful approach to supplement missing structural information with atomic detail. We combine RosettaNMR with experimentally-derived paramagnetic NMR restraints to guide membrane protein structure prediction. We demonstrate this approach using the disulfide bond formation protein B (DsbB), an α-helical IMP. Here, we attached a cyclen-based paramagnetic lanthanide tag to an engineered non-canonical amino acid (ncAA) using a copper-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry reaction. Using this tagging strategy, we collected 203 backbone HN pseudocontact shifts (PCSs) for three different labeling sites and used these as input to guide de novo membrane protein structure prediction protocols in Rosetta. We find that this sparse PCS dataset combined with 44 long-range NOEs as restraints in our calculations improves structure prediction of DsbB by enhancements in model accuracy, sampling, and scoring. The inclusion of this PCS dataset improved the Cα-RMSD transmembrane segment values of the best-scoring and best-RMSD models from 9.57 Å and 3.06 Å (no NMR data) to 5.73 Å and 2.18 Å, respectively.

Surface Engineering of Lanthanide Nanoparticles for Oncotherapy.

Surface-modified lanthanide nanoparticles have been widely developed as an emerging class of therapeutics for cancer treatment because they exhibit several unique properties. First, lanthanide nanoparticles exhibit a variety of diagnostic capabilities suitable for various image-guided therapies. Second, a large number of therapeutic molecules can be accommodated on the surface of lanthanide nanoparticles, which can simultaneously achieve combined cancer therapy. Third, multivalent targeting ligands on lanthanide nanoparticles can be easily modified to achieve high affinity and specificity for target cells. Last but not least, lanthanide nanoparticles can be engineered for spatially and temporally controlled tumor therapy, which is critical for developing precise and personalized tumor therapy. Surface-modified lanthanide-doped nanoparticles are widely used in cancer phototherapy. This is due to their unique optical properties, including large anti-Stokes shifts, long-lasting luminescence, high photostability, and the capacity for near-infrared or X-ray excitation. Upon near-infrared irradiation, these nanoparticles can emit ultraviolet to visible light, which activates photosensitizers and photothermal agents to destroy tumor cells. Surface modification with special ligands that respond to tumor microenvironment changes, such as acidic pH, hypoxia, or redox reactions, can turn lanthanide nanoparticles into a smart nanoplatform for light-guided tumor chemotherapy and gene therapy. Surface-engineered lanthanide nanoparticles can include antigens that elicit tumor-specific immune responses, as well as immune activators that boost immunity, allowing distant and metastatic tumors to be eradicated. The design of ligands and surface chemistry is crucial for improving cancer therapy without causing side effects. In this Account, we classify surface-modified lanthanide nanoparticles for tumor therapy into four main domains: phototherapy, radiotherapy, chemotherapy, and biotherapy. We begin by introducing fundamental bioapplications and then discuss recent developments in tumor phototherapy (photodynamic therapy and photothermal therapy), radiotherapy, chemotherapy, and biotherapy (gene therapy and immunotherapy). We also assess the viability of a variety of strategies for eliminating tumor cells through innovative pathways. Finally, future opportunities and challenges for the development of more efficient lanthanide nanoprobes are discussed.

Identification of a TonB-Dependent Receptor Involved in Lanthanide Switch by the Characterization of Laboratory-Adapted Methylosinus trichosporium OB3b.

Two methanol dehydrogenases (MDHs), MxaFI and XoxF, have been characterized in methylotrophic and methanotrophic bacteria. MxaFI contains a calcium ion in its active site, whereas XoxF contains a lanthanide ion. Importantly, the expression of MxaFI and XoxF is inversely regulated by lanthanide bioavailability, i.e., the "lanthanide switch." To reveal the genetic and environmental factors affecting the lanthanide switch, we focused on two Methylosinus trichosporium OB3b mutants isolated during routine cultivation. In these mutants, MxaF was constitutively expressed, but lanthanide-dependent XoxF1 was not, even in the presence of 25 µM cerium ions, which is sufficient for XoxF expression in the wild type. Genotyping showed that both mutants harbored a loss-of-function mutation in the CQW49_RS02145 gene, which encodes a TonB-dependent receptor. Gene disruption and complementation experiments demonstrated that CQW49_RS02145 was required for XoxF1 expression in the presence of 25 µM cerium ions. Phylogenetic analysis indicated that CQW49_RS02145 was homologous to the Methylorubrum extorquens AM1 lanthanide transporter gene (lutH). These findings suggest that CQW49_RS02145 is involved in lanthanide uptake across the outer membrane. Furthermore, we demonstrated that supplementation with cerium and glycerol caused severe growth arrest in the wild type. CQW49_RS02145 underwent adaptive laboratory evolution in the presence of cerium and glycerol ions, resulting in a mutation that partially mitigated the growth arrest. This finding implies that loss-of-function mutations in CQW49_RS02145 can be attributed to residual glycerol from the frozen stock. IMPORTANCE Lanthanides are widely used in many industrial applications, including catalysts, magnets, and polishing. Recently, lanthanide-dependent metabolism was characterized in methane-utilizing bacteria. Despite the global demand for lanthanides, few studies have investigated the mechanism of lanthanide uptake by these bacteria. In this study, we identify a lanthanide transporter in Methylosinus trichosporium OB3b and indicate the potential interaction between intracellular lanthanide and glycerol. Understanding the genetic and environmental factors affecting lanthanide uptake should not only help improve the use of lanthanides for the bioconversion of methane into valuable products like methanol but also be of value for developing biomining to extract lanthanides under neutral conditions.

Orthogonal excitations of lanthanide nanoparticle up/down conversion emissions via switching NIR lights for in-vivo theranostics.

With multiple emissions ranging from NIR-IIb to visible lights, near-infrared light-excited lanthanide nanoparticle (LnNP) is an ideal in-vivo theranostic platform to achieve imaging guided phototherapy. However, current reported LnNPs typically demonstrate simultaneous up and downconversion emissions with fixed single excitation light, which impairs therapeutic efficiency and generates side effect during navigation. Here we develop a lanthanide-based conversion switching nanoparticle (CSNP) with independent activation of 1550 nm NIR-IIb downconversion emission under 808 nm excitation and 345/450 nm upconversion emission under 980 nm excitation. CSNP is modified with Cy-GSH to quench NIR-IIb emission and photosensitizer hypocrellin A. In vivo delivery of CSNP is traced via 808 nm irradiation, and Cy-GSH changes structure in response to glutathione to activate NIR-IIb imaging. This indicates the tumor position and timing to switch for 980 nm irradiation to activate hypocrellin A for photodynamic therapy. Orthogonal activation of CSNP up/down conversion emissions demonstrates high tumor-to-normal tissue ratio in vivo and good therapeutic result, would have promising potential as a theranostics platform.

Nanobody GPS by PCS: An Efficient New NMR Analysis Method for G Protein Coupled Receptors and Other Large Proteins.

NMR chemical shift changes can report on the functional dynamics of biomacromolecules in solution with sizes >1 MDa. However, their interpretation requires chemical shift assignments to individual nuclei, which for large molecules often can only be obtained by tedious point mutations that may interfere with function. We present here an efficient pseudocontact shift NMR method to assign biomacromolecules using bound antibodies tagged with lanthanoid DOTA chelators. The stability of the antibody allows positioning the DOTA tag at many surface sites, providing triangulation of the macromolecule nuclei at distances >60 Å. The method provides complete assignments of valine and tyrosine 1H-15N resonances of the ß1-adrenergic receptor in various functional forms. The detected chemical shift changes reveal strong forces exerted onto the backbone of transmembrane helix 3 during signal transmission, which are absorbed by its electronic structure. The assignment method is applicable to any soluble biomacromolecule for which suitable complementary binders exist.

Pr3+ doped NaYF4 and LiYF4 nanocrystals combining visible-to-UVC upconversion and NIR-to-NIR-II downconversion luminescence emissions for biomedical applications.

Lanthanide-doped fluoride nanocrystals (NCs) are known to exhibit unique optical properties, such as upconversion and downconversion luminescence (UCL and DCL), which can be employed for various applications. In this work, we demonstrate that by doping praseodymium(III) and ytterbium(III) ions (Pr3+ and Yb3+) into a nanosized fluoride matrix (i.e. NaYF4 and LiYF4), it is possible to combine their UCL and DCL properties that can be concurrently used for biomedical applications. In particular, the emissive modes combined in a single nanoparticle co-doped with Pr3+ and Yb3+ include DCL emission (excited at 980 nm and peaked at 1320 nm), which can be used for near infrared (NIR) DCL bioimaging in the NIR-II window of biological tissue transparency (∼1000-1350 nm) and UCL emission (excited at 447 nm and peaked at 275 nm) that can be employed for germicide action (via irradiation by light in the UVC range). A possibility of the latter was demonstrated by the denaturation of double-stranded DNA (dsDNA) into single-stranded ones that was caused by the UVC UCL emission from the NCs under 447 nm irradiation; it was evidenced by the hyperchromicity observed in the irradiated dsDNA solution and also by a fluorometric analysis of DNA unwinding (FADU) assay. Concurrently, the possibility of NIR-II luminescence bioimaging through biological tissues (bovine tooth and chicken flesh) was demonstrated. The proposed concept paves a way for NIR-II imaging guided antimicrobial phototherapy using lanthanide-doped fluoride nanocrystals.

Upconversion Nanostructures Applied in Theranostic Systems.

Upconversion (UC) nanostructures, which can upconvert near-infrared (NIR) light with low energy to visible or UV light with higher energy, are investigated for theranostic applications. The surface of lanthanide (Ln)-doped UC nanostructures can be modified with different functional groups and bioconjugated with biomolecules for therapeutic systems. On the other hand, organic molecular-based UC nanostructures, by using the triplet-triplet annihilation (TTA) UC mechanism, have high UC quantum yields and do not require high excitation power. In this review, the major UC mechanisms in different nanostructures have been introduced, including the Ln-doped UC mechanism and the TTA UC mechanism. The design and fabrication of Ln-doped UC nanostructures and TTA UC-based UC nanostructures for theranostic applications have been reviewed and discussed. In addition, the current progress in the application of UC nanostructures for diagnosis and therapy has been summarized, including tumor-targeted bioimaging and chemotherapy, image-guided diagnosis and phototherapy, NIR-triggered controlled drug releasing and bioimaging. We also provide insight into the development of emerging UC nanostructures in the field of theranostics.

Intelligent modelling for the elimination of lanthanides (La3+, Ce3+, Nd3+ and Eu3+) from aqueous solution by magnetic CoFe2O4 and CoFe2O4-GO spinel ferrite nanocomposites.

In this research, a novel CoFe2O4-GO (Graphen Oxide) resulting from the combination of high applicable magnetic and organic base materials and synthesized with a simple and fast co-precipitation route was synthesized for the REEs (Rare Earth Elements) extraction. This adsorbent could remove the La3+, Ce3+, Nd3+ and Eu3+ by maximum adsorption capacity of 625, 626, 714.2, 1111.2 mg/g at optimized pH = 6, respectively. A data-driven model was obtained using Group Method of Data Handling (GMDH)-based Neural Network to estimate the adsorption capacity of these LREEs as a function of time, pH, temperature, adsorbent ζ (zeta)- potential, initial concentration of lanthanides ions, and ε which is defined by the physico-chemical properties of lanthanides. The results clearly indicated that the model estimate the experimental values with good deviation (mostly less than 10%) and it can be used for the prediction of the results from other similar researches with less than 25% deviation. The results of sensitivity analysis indicated that the adsorption capacity is more sensitive to pH of the solution, temperature, and ε. Finally, the desorption studies showed an excellent removal efficiency (97%) at least for three adsorption-desorption cycles. These results claimed that the CoFe2O4-GO is a highly efficient adsorbent for the REEs extraction.

A smartphone-integrated light-up lanthanide fluorescent probe for the visual and ratiometric detection of total phosphorus in human urine and environmental water samples.

Phosphate (Pi) plays an essential role in aquatic ecosystems as well as in physiological processes. Here, a dual-emission probe for the sensitive, specific and visual analysis of Pi is fabricated by coordinating Eu3+ with luminol and 2,6-pyridinedicarboxylic acid (DPA). Pi can significantly enhance the characteristic fluorescence of Eu3+ at 615 nm by promoting energy transfer from DPA to Eu3+ and reducing the quenching effect of water molecule, luminol with inherent emission at 423 nm further enhances the Eu3+ fluorescence. Accordingly, ratiometric detection of Pi can be achieved with the fluorescence ratio F615/F423 as a function of Pi concentration. Linearity between F615/F423 and Pi concentration in the range of 0.1-25 µM is shown, and the limit of detection (LOD, 3σ/K) for Pi is 0.027 µM. In addition, a continuous change in the fluorescence color of the probe from blue to red is observed with increasing Pi concentration under a UV lamp, and a smartphone-based visual method is used for the convenient and effective semi-quantitative determination of Pi. The dual-emission probe has been successfully applied to ratiometric and visual analysis of Pi in human urine and environmental water samples, and adequate results are obtained.

Phytoglycogen Encapsulation of Lanthanide-Based Nanoparticles as an Optical Imaging Platform with Therapeutic Potential.

Lanthanide-based upconverting nanoparticles (UCNPs) are largely sought-after for biomedical applications ranging from bioimaging to therapy. A straightforward strategy is proposed here using the naturally sourced polymer phytoglycogen to coencapsulate UCNPs with hydrophobic photosensitizers as an optical imaging platform and light-induced therapeutic agents. The resulting multifunctional sub-micrometer-sized luminescent beads are shown to be cytocompatible as carrier materials, which encourages the assessment of their potential in biomedical applications. The loading of UCNPs of various elemental compositions enables multicolor hyperspectral imaging of the UCNP-loaded beads, endowing these materials with the potential to serve as luminescent tags for multiplexed imaging or simultaneous detection of different moieties under near-infrared (NIR) excitation. Coencapsulation of UCNPs and Rose Bengal opens the door for potential application of these microcarriers for collagen crosslinking. Alternatively, coloading UCNPs with Chlorin e6 enables NIR-light triggered generation of reactive oxygen species. Overall, the developed encapsulation methodology offers a straightforward and noncytotoxic strategy yielding water-dispersible UCNPs while preserving their bright and color-tunable upconversion emission that would allow them to fulfill their potential as multifunctional platforms for biomedical applications.

Intensifying Upconverted Ultraviolet Emission towards Efficient Reactive Oxygen Species Generation.

Multiphoton upconversion that can convert near-infrared irradiation into ultraviolet emission offers many unique opportunities for photocatalysis and phototherapy. However, the high-lying excited states of lanthanide emitters are often quenched by the interior lattice defects and deleterious interactions among different lanthanides, resulting in weak ultraviolet emission. Here, we describe a novel excitation energy lock-in approach to boost ultraviolet upconversion emission in a new class of multilayer core-shell nanoparticles with a gadolinium-rich core domain. Remarkably, we observe more than 70-fold enhancements in Gd3+ emission from the designed nanoparticles compared with the conventional nanoparticles. Our mechanistic investigation reveals that the combination of energy migration over the core domain and optically inert NaYF4 interlayer can effectively confine the excitation energy and thus lead to intense multiphoton ultraviolet emission in upconversion nanostructures. We further achieve a 35.6% increase in photocatalytic reactivity and 26.5% in reactive oxygen species production yield in ZnO-coated upconversion nanocomposites under 808-nm excitation. This study provides a new insight to energy transfer mechanism in lanthanide-doped nanoparticles and offers an exciting avenue for exploring novel near-infrared photocatalysts.

Innovative construction of a novel lanthanide cerate nanostructured photocatalyst for efficient treatment of contaminated water under sunlight.

Herein, we have developed Ln2Ce2O7 (Ln = Er, Ho) ceramic nanostructures through a rapid and green sonochemical approach and scrutinized their photocatalytic efficiency toward degradation of toxic pollutants under sunlight. Salvia rosmarinus extract is utilized as a morphology-directing agent in the sono-synthesis of the nanostructured Ln2Ce2O7 (Ln = Er, Ho), for the first time. Comprehensive characterization utilizing different techniques demonstrated that introducing of rare-earth metals, erbium and holmium, affected the textural, morphological, and optical features of the nanostructured ceria. The energy gap for pure cerium dioxide nanostructure was estimated to be 3.09 eV, while the energy gap for Ho2Ce2O7 and Er2Ce2O7 nanostructure was estimated at 2.9 and 2.66 eV, respectively. The narrowing of the energy gap was observed as a result of the introduction of rare-earth metals, erbium and holmium, especially erbium, into the nanostructured ceria. Investigation of the photocatalytic decomposition of various contaminants revealed that the introduction of erbium has remarkably enhanced the photocatalytic activity of nanostructured ceria. High photocatalytic performance (98.9%) and rate constant (0.0727 min-1) was observed for the Er2Ce2O7 nanostructure in the removal of eriochrome Black T. Improving the optical features of ceria nanostructure as well as enhancing its specific area were reasons that could increase the photocatalytic efficiency. The photocatalytic decomposition reactions in the removal of toxic contaminants were well accorded with the Pseudo-first order reaction kinetics. Besides, the nanostructured Er2Ce2O7 maintained its efficiency after ten reaction cycles and did not denote any notable decline in efficiency. The use of this novel porous nanostructure can be a potentially efficient solution for water treatment.

Selective carbon-phosphorus bond cleavage: expanding the toolbox for accessing bulky divalent lanthanoid sandwich complexes.

The synthesis of two new tetra- and penta-phenycyclopentadienyldiphenylphosphine pro-ligands which readily undergo selective C-P bond cleavage has allowed for the facile synthesis of bulky divalent octa- and deca-phenylmetallocenes of europium, ytterbium and samarium.

Quaternary Selenides EuLnCuSe3: Synthesis, Structures, Properties and In Silico Studies.

In this work, we report on the synthesis, in-depth crystal structure studies as well as optical and magnetic properties of newly synthesized heterometallic quaternary selenides of the Eu+2Ln+3Cu+1Se3 composition. Crystal structures of the obtained compounds were refined by the derivative difference minimization (DDM) method from the powder X-ray diffraction data. The structures are found to belong to orthorhombic space groups Pnma (structure type Ba2MnS3 for EuLaCuSe3 and structure type Eu2CuS3 for EuLnCuSe3, where Ln = Sm, Gd, Tb, Dy, Ho and Y) and Cmcm (structure type KZrCuS3 for EuLnCuSe3, where Ln = Tm, Yb and Lu). Space groups Pnma and Cmcm were delimited based on the tolerance factor t', and vibrational spectroscopy additionally confirmed the formation of three structural types. With a decrease in the ionic radius of Ln3+ in the reported structures, the distortion of the (LnCuSe3) layers decreases, and a gradual formation of the more symmetric structure occurs in the sequence Ba2MnS3 → Eu2CuS3 → KZrCuS3. According to magnetic studies, compounds EuLnCuSe3 (Ln = Tb, Dy, Ho and Tm) each exhibit ferrimagnetic properties with transition temperatures ranging from 4.7 to 6.3 K. A negative magnetization effect is observed for compound EuHoCuSe3 at temperatures below 4.8 K. The magnetic properties of the discussed selenides and isostructural sulfides were compared. The direct optical band gaps for EuLnCuSe3, subtracted from the corresponding diffuse reflectance spectra, were found to be 1.87-2.09 eV. Deviation between experimental and calculated band gaps is ascribed to lower d states of Eu2+ in the crystal field of EuLnCuSe3, while anomalous narrowing of the band gap of EuYbCuSe3 is explained by the low-lying charge-transfer state. Ab initio calculations of the crystal structures, elastic properties and phonon spectra of the reported compounds were performed.

Plasmon-Triggered Upconversion Emissions and Hot Carrier Injection for Combinatorial Photothermal and Photodynamic Cancer Therapy.

Despite the unique ability of lanthanide-doped upconversion nanoparticles (UCNPs) to convert near-infrared (NIR) light to high-energy UV-vis radiation, low quantum efficiency has rendered their application unpractical in biomedical fields. Here, we report anatase titania-coated plasmonic gold nanorods decorated with UCNPs (Au NR@aTiO2@UCNPs) for combinational photothermal and photodynamic therapy to treat cancer. Our novel architecture employs the incorporation of an anatase titanium dioxide (aTiO2) photosensitizer as a spacer and exploits the localized surface plasmon resonance (LSPR) properties of the Au core. The LSPR-derived near-field enhancement induces a threefold boost of upconversion emissions, which are re-absorbed by neighboring aTiO2 and Au nanocomponents. Photocatalytic experiments strongly infer that LSPR-induced hot electrons are injected into the conduction band of aTiO2, generating reactive oxygen species. As phototherapeutic agents, our hybrid nanostructures show remarkable in vitro anticancer effect under NIR light [28.0% cancer cell viability against Au NR@aTiO2 (77.3%) and UCNP@aTiO2 (98.8%)] ascribed to the efficient radical formation and LSPR-induced heat generation, with cancer cell death primarily following an apoptotic pathway. In vivo animal studies further confirm the tumor suppression ability of Au NR@aTiO2@UCNPs through combinatorial photothermal and photodynamic effect. Our hybrid nanomaterials emerge as excellent multifunctional phototherapy agents, providing a valuable addition to light-triggered cancer treatments in deep tissue.

Native point defect modulated Cr3+-LaAlO3 as an in vitro excited contrast medium for in vivo near-infrared persistent deep-tissue bio-imaging.

Due to the synergistic effect of Cr3+ dopant levels and defect state, the luminescence intensity and decay time in LaAlO3 are remarkably enhanced, and the emission wavelength from deep-red (Cr3+ as the luminescent center) to NIR-II/III (defect states as the luminescent center) can be effectively tuned via an energy transfer process.

Engineering luminescent pectin-based hydrogel for highly efficient multiple sensing.

Luminescent hydrogels with sensing capabilities have attracted much interest in recent years, especially those responsive to stimuli, making such materials potential for various applications. Pectin is a high-molecular-weight carbohydrate polymer that has the ability to form hydrogel upon heating or mixing with divalent cations. However, intrinsic pectin gels are weak and lack of functionalities. In this study, lanthanide ions and silk fibroin derived carbon dots were incorporated into Pectin/PVA hydrogel (PPH) to form luminescent tough hydrogels. The luminescence of the hydrogel can be tuned by adjusting the ratio of blue emission carbon dots to Eu3+ ions (red emission) and Tb3+ ions (green emission). Such incorporation of emitters only slightly changed the mechanical properties of the tough hydrogel. Notably, the luminescent Pectin/PVA hydrogel (LPPH) showed chromic response to external stimuli, like pH and metal ions. By measuring the ratio of luminescent intensity at 473 nm and 617 nm (I473/I617), the pH response can be quantified in high sensitivity. In addition, the specific detection of Cu2+ and Fe3+ ions using the fabricated hydrogel were demonstrated, the mechanism was also proposed. The different chromic responses to Fe2+ and Fe3+ endow the luminescent tough Pectin/PVA hydrogel potential for multiple sensing applications.