The design of bright NIR‐II luminescent nanomaterials that enable efficient labelling of proteins without disturbing their physiological properties in vivo is challenging. We developed an efficient ...strategy to synthesize bright NIR‐II gold nanoclusters (Au NCs) protected by biocompatible cyclodextrin (CD). Leveraging the ultrasmall size of Au NCs (<2 nm) and strong macrocycle‐based host–guest chemistry, the as‐synthesized CD‐Au NCs can readily label proteins/antibodies. Moreover, the labelled proteins/antibodies enable highly efficient in vivo tracking during blood circulation, without disturbing their biodistribution and tumor targeting ability, thus leading to a sensitive tumor‐targeted imaging. CD‐Au NCs are stable in the harsh biological environment and show good biocompatibility and high renal clearance efficiency. Therefore, the NIR‐II biolabels developed in this study provide a promising platform to monitor the physiological behavior of biomolecules in living organisms.
Bright NIR‐II Au nanoclusters (NCs) were rationally synthesized by using biocompatible cyclodextrin (CD) as the ligands. The renal‐clearable CD‐Au NCs can readily label proteins/antibodies via strong macrocycle‐based host–guest chemistry and enable highly efficient in vivo tracking during blood circulation, without disturbing their biodistribution and tumor targeting ability, thus leading to a sensitive tumor‐targeted NIR‐II visualization.
Within decades of development, carbon nanomaterials such as carbon black, fullerene, carbon nanotube, carbon nanofiber, graphene and their combined nanofillers have been tremendously applied in ...polymer material industries, generating a series of fascinating multifunctional composites in the fields from portable electronic devices, sports, entertainments to automobile, aerospace and military. Among the various material properties of the composites, electrical conductivity and mechanical performance are the two most important parameters for evaluating the effectiveness of nanofillers in the polymer matrices. In this review, we focus on the electrical and mechanical properties of diverse dimensional carbon nanofillers (e.g., zero-, one-, two-, three-dimensional nanofillers or their combinations)-reinforced polymer composites to seek the most efficient and effective approach to obtain high-performance polymeric nanocomposites.
Impurity doping is an effective approach to tuning the optoelectronic performance of host materials by imparting extrinsic electronic channels. Herein, a family of lanthanide (Ln
) ions was ...successfully incorporated into a Bi:Cs
AgInCl
lead-free double-perovskite (DP) semiconductor, expanding the spectral range from visible (Vis) to near-infrared (NIR) and improving the photoluminescence quantum yield (PLQY). After multidoping with Nd, Yb, Er and Tm, Bi/Ln:Cs
AgInCl
yielded an ultrabroadband continuous emission spectrum with a full width at half-maximum of ~365 nm originating from intrinsic self-trapped exciton recombination and abundant 4f-4f transitions of the Ln
dopants. Steady-state and transient-state spectra were used to ascertain the energy transfer and emissive processes. To avoid adverse energy interactions between the various Ln
ions in a single DP host, a heterogeneous architecture was designed to spatially confine different Ln
dopants via a "DP-in-glass composite" (DiG) structure. This bottom-up strategy endowed the prepared Ln
-doped DIG with a high PLQY of 40% (nearly three times as high as that of the multidoped DP) and superior long-term stability. Finally, a compact Vis-NIR ultrabroadband (400~2000 nm) light source was easily fabricated by coupling the DiG with a commercial UV LED chip, and this light source has promising applications in nondestructive spectroscopic analyses and multifunctional lighting.
Lanthanide‐doped upconversion nanoparticles (UCNPs) have shown great promise in bioapplications. Exploring new host materials to realize efficient upconversion luminescence (UCL) output is a goal of ...general concern. Herein, we develop a unique strategy for the synthesis of novel LiLuF4:Ln3+ core/shell UCNPs with typically high absolute upconversion quantum yields of 5.0 % and 7.6 % for Er3+ and Tm3+, respectively. Based on our customized UCL biodetection system, we demonstrate for the first time the application of LiLuF4:Ln3+ core/shell UCNPs as sensitive UCL bioprobes for the detection of an important disease marker β subunit of human chorionic gonadotropin (β‐hCG) with a detection limit of 3.8 ng mL−1, which is comparable to the β‐hCG level in the serum of normal humans. Furthermore, we use these UCNPs in proof‐of‐concept computed tomography imaging and UCL imaging of cancer cells, thus revealing the great potential of LiLuF4:Ln3+ UCNPs as efficient nano‐bioprobes in disease diagnosis.
A small but sensitive biosensor: Successive injection of shell precursors enabled the synthesis of novel and highly emissive LiLuF4:Ln3+ core/shell upconversion nanoparticles that were effective as sensitive upconversion luminescent probes for the detection of β‐hCG (an important disease marker). The nanoprobes were also used successfully in proof‐of‐concept computed tomography and upconversion luminescence dual‐mode bioimaging.
A strategy is proposed to fabricate dual‐mode luminescent NaGdF4 nanocrystals that are composed of NaGdF4:Yb3+,Tm3+ core and NaGdF4:Eu3+ shell. Intense downconversion via the sensitization of Gd3+ ...and upconversion luminescence of Eu3+ that is one order of magnitude higher than the triply‐doped core only counterparts have been achieved by employing the distinct core/shell nanostructures and double sensitizations of Yb3+ and Tm3+.
Applications of persistent luminescence phosphors as night or dark‐light vision materials in many technological fields have fueled up a growing demand for rational control over the emission profiles ...of the phosphors. This, however, remains a daunting challenge. Now a unique strategy is reported to fine‐tune the persistent luminescence by using all‐inorganic CsPbX3 (X=Cl, Br, and I) perovskite quantum dots (PeQDs) as efficient light‐conversion materials. Full‐spectrum persistent luminescence with wavelengths covering the entire visible spectral region is achieved through tailoring of the PeQD band gap, in parallel with narrow bandwidth of PeQDs and highly synchronized afterglow decay owing to the single energy storage source. These findings break through the limitations of traditional afterglow phosphors, thereby opening up opportunities for persistent luminescence materials for applications such as a white‐emitting persistent light source and dark‐light multicolor displays.
A unique and versatile strategy is proposed to fine‐tune the persistent luminescence over the entire visible spectral region with narrow bandwidth and highly synchronized afterglow decay. It uses a CaAl2O4:Eu2+,Nd3+ (CAO) afterglow phosphor as the single energy storage source and all‐inorganic CsPbX3 (X=Cl, Br, and I) perovskite quantum dots (PeQDs) as efficient light conversion materials.
All‐inorganic cesium lead halide perovskite nanocrystals (NCs) with different dimensionalities have recently fascinated the research community due to their extraordinary optoelectronic performance ...such as tunable bandgaps over the entire visible spectral region. However, compared to well‐developed 3D CsPbX3 perovskites (X = Cl, Br, and I), the bandgap tuning in 0D Cs4PbX6 perovskite NCs remains an arduous task. Herein, a simple but valid strategy is proposed to tailor the insulator bandgap (≈3.96 eV) of Cs4PbBr6 NCs to the blue spectral region by changing the local coordination environment of isolated PbBr64− octahedra in the Cs4PbBr6 crystal through Sn cation doping. Benefitting from the unique Pb2+‐poor and Br−‐rich reaction environment, the Sn cation is successfully introduced into the Cs4PbBr6 NCs, forming coexisting point defects comprising substitutional SnPb and interstitial Bri, thereby endowing these theoretically nonluminescent Cs4PbBr6 NCs with an ultranarrow blue emission at ≈437 nm (full width at half maximum, ≈12 nm). By combining the experimental results with first‐principles calculations, an unusual electronic dual‐bandgap structure, comprising the newly emerged semiconducting bandgap of ≈2.87 eV and original insulator bandgap of ≈3.96 eV, is found to be the underlying fundamental reason for the ultranarrow blue emission.
A simple but valid strategy of Sn cation doping is proposed to tailor the insulator bandgap (≈3.96 eV) of 0D Cs4PbBr6 perovskite nanocrystals (NCs) in the blue spectral region, thereby endowing these theoretically nonluminescent 0D Cs4PbBr6 perovskite NCs with an ultranarrow blue emission at ≈437 nm (full width at half maximum, 12 nm).
All-inorganic CsPbX
(X = Cl, Br, and I) perovskite quantum dots (PeQDs) have shown great promise in optoelectronics and photovoltaics owing to their outstanding linear optical properties; however, ...nonlinear upconversion is limited by the small cross-section of multiphoton absorption, necessitating high power density excitation. Herein, we report a convenient and versatile strategy to fine tuning the upconversion luminescence in CsPbX
PeQDs through sensitization by lanthanide-doped nanoparticles. Full-color emission with wavelengths beyond the availability of lanthanides is achieved through tailoring of the PeQDs bandgap, in parallel with the inherent high conversion efficiency of energy transfer upconversion under low power density excitation. Importantly, the luminescent lifetimes of the excitons can be enormously lengthened from the intrinsic nanosecond scale to milliseconds depending on the lifetimes of lanthanide ions. These findings provide a general approach to stimulate photon upconversion in PeQDs, thereby opening up a new avenue for exploring novel and versatile applications of PeQDs.
Near-infrared (NIR) II luminescence between 1000 and 1700 nm has attracted reviving interest for biosensing due to its unique advantages such as deep-tissue penetration and high spatial resolution. ...Traditional NIR-II probes such as organic fluorophores usually suffer from poor photostability and potential long-term toxicity. Herein, we report the controlled synthesis of monodisperse NaCeF4:Er/Yb nanocrystals (NCs) that exhibit intense NIR-II emission upon excitation at 980 nm. Ce3+ in the host lattice was found to enhance the luminescence of Er3+ at 1530 nm with a maximum NIR-II quantum yield of 32.8%, which is the highest among Er3+-activated nanoprobes. Particularly, by utilizing the intense NIR-II emission of NaCeF4:Er/Yb NCs, we demonstrated their application as sensitive homogeneous bioprobes to detect uric acid with the limit of detection down to 25.6 nM. Furthermore, the probe was detectable in tissues at depths of up to 10 mm, which enabled in vivo imaging of mouse organs and hindlimbs with high resolution, thus revealing the great potential of these NaCeF4:Er/Yb nanoprobes in deep-tissue diagnosis.
Lanthanide‐doped upconversion nanoparticles (UCNPs) have shown great promise in versatile bioapplications. For the first time, organosilica‐shelled β‐NaLuF4:Gd/Yb/Er nanoprobes with a rattle ...structure have been designed for dual‐modal imaging and photodynamic therapy (PDT). Benefiting from the unique rattle structure and aromatic framework, these nanoprobes are endowed with a high loading capacity and the disaggregation effect of photosensitizers. After loading of β‐carboxyphthalocyanine zinc or rose Bengal into the nanoprobes, we achieved higher energy transfer efficiency from UCNPs to photosensitizers as compared to those with conventional core–shell structure or with pure‐silica shell, which facilitates a large production of singlet oxygen and thus an enhanced PDT efficacy. We demonstrated the use of these nanoprobes in proof‐of‐concept X‐ray computed tomography (CT) and UC imaging, thus revealing the great potential of this multifunctional material as an excellent nanoplatform for cancer theranostics.
Rattle‐structured nano‐bioprobes featuring a β‐NaLuF4:Gd/Yb/Er core and a benzene‐bridged organosilica shell exhibit a high loading capacity and the disaggregation effect of photosensitizers, providing enhanced photodynamic therapy. Together with the functions of upconversion/X‐ray computed tomography (UC/CT) dual‐modal imaging and tumor‐targeting, these nanoprobes are highly promising for cancer theranostics.
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