Photothermal therapy (PTT) is one of the most promising approaches to combat multidrug‐resistant bacteria with less potential to induce resistance and systemic toxicity. However, uncontrollable ...distribution of photothermal agents leads to lethal temperatures for normal cells, and failure to offer timely and effective antibacterial stewardship. A pH switchable nanoplatform for persistent luminescence imaging‐guided precise PTT to selectively destroy only pathological cells while protecting nearby normal cells in bacterial infected microenvironment is shown. The PLNP@PANI‐GCS is fabricated by grafting polyaniline (PANI) and glycol chitosan (GCS) onto the surface of persistent luminescence nanoparticles (PLNPs). It takes advantage of the long persistent luminescence of PLNPs to realize autofluorescence‐free imaging, the pH‐dependent light–heat conversion property of PANI to get a stronger photothermal effect at pH 6.5 than pH 7.4, and the pH environment responsive surface charge transition of GCS. Consequently, PLNP@PANI‐GCS enables effective response to bacterial‐infected acid region and electrostatic bonding to bacteria in vivo, ensuring the spatial accuracy of near‐infrared light irradiation and specific heating directly to bacteria. In vivo imaging‐guided PTT to bacterial infection abscess shows effective treatment. PLNP@PANI‐GCS has great potential in treating multidrug‐resistant bacterial infection with low possibility of developing microbial drug resistance and little harm to normal cells.
A pH switchable nanoplatform is developed for in vivo persistent luminescent imaging and precise photothermal therapy of bacterial infections. This nanoplatform exhibits specific photothermal therapy to acidic bacterial‐infected regions but no damage to normal tissues.
Design of stable adsorbents for selective gold recovery with large capacity and fast adsorption kinetics is of great challenge, but significant for the economy and the environment. Herein, we show ...the design and preparation of an irreversible amide‐linked covalent organic framework (COF) JNU‐1 via a building block exchange strategy for efficient recovery of gold. JNU‐1 was synthesized through the exchange of 4,4′‐biphenyldicarboxaldehyde (BA) in mother COF TzBA consisting of 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline (Tz) and BA with terephthaloyl chloride. The irreversible amide linked JNU‐1 gave good stability, unprecedented fast kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery. X‐ray photoelectron spectroscopy along with thermodynamic study and quantum mechanics calculation reveals that the excellent performance of JNU‐1 for gold recovery results from the formation of hydrogen bonds C(N)−H⋅⋅⋅Cl and coordinate interaction of O and Au. The rational design of irreversible bonds as both inherent linkage and functional groups in COFs is a promising way to prepare stable COFs for diverse applications.
Going for gold: A building‐block exchange strategy gave an irreversible amide‐linked covalent organic framework (COF). The irreversible‐amide linked COF gave good stability, unprecedented fast adsorption kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery.
Persistent luminescent nanoparticles (PLNPs) with intrinsic stimuli‐responsive properties are desirable because of no autofluorescence background and natural responsive luminescence. However, the ...stimuli‐responsive features of pure PLNPs have been unexplored. Here we show a facile one‐pot hydrothermal synthesis of green‐emitting Zn2GeO4:Mn2+,Pr3+ nanoparticles (ZGMP) with regular shape, uniform size and good afterglow luminescent performance. We also report the pH stimuli‐responsive luminescent behavior of ZGMP and its possible mechanism. Taking the intriguing feature of pH responsive persistent luminescence, we explore ZGMP as autofluorescence‐free probes to achieve stimuli‐activated signal switch for biosensing by integrating enzyme catalysis reaction mediated pH modulation. The pH‐responsive persistent luminescence also makes ZGMP promising for high‐level information encryption.
Uniformly torpedo‐shaped green‐emitting Zn2GeO4: Mn2+, Pr3+ nanoparticles with good persistent luminescence performance were synthesized by a simple hydrothermal method. The pH‐responsive persistent luminescence of ZGMP was found and explored for autofluorescence‐free biosensing and high‐level information encryption.
Conspectus Persistent luminescence nanoparticles (PLNPs) are unique optical materials emitting long-lasting luminescence after ceasing excitation. Such a unique optical feature allows luminescence ...detection without constant external illumination to avoid the interferences of autofluorescence and scattering light from biological fluids and tissues. Besides, near-infrared (NIR) PLNPs have advantages of deep penetration and the reactivation of the persistent luminescence (PL) by red or NIR light. These features make the application of NIR-emitting PLNPs in long-term bioimaging no longer limited by the lifetime of PL. To take full advantage of PLNPs for biological applications, the versatile strategies for bridging PLNPs and biological system become increasingly significant for the design of PLNPs-based nanoprobes. In this Account, we summarize our systematic achievements in the biological applications of PLNPs from biosensing/bioimaging to theranostics with emphasizing the engineering strategies for fabricating specific PLNPs-based nanoprobes. We take surface engineering and manipulating energy transfer as the major principles to design various PLNPs-based nanoprobes based on the nature of interactions between nanoprobes and targets. We have developed target-induced formation or interruption of fluorescence resonance energy transfer systems for autofluorescence-free biosensing and imaging of cancer biomarkers. We have decorated single or dual targeting ligands on PLNPs for tumor-targeted imaging, and integrated other modal imaging agents into PLNPs for multimodal imaging. We have also employed specific functionalization for various biomedical applications including chemotherapy, photodynamic therapy, photothermal therapy, stem cells tracking and PL imaging-guided gene therapy. Besides, we have modified PLNPs with multiple functional units to achieve challenging metastatic tumor theranostics. The proposed design principle and comprehensive strategies show great potential in guiding the design of PLNPs nanoprobes and promoting further development of PLNPs in the fields of biological science and medicine. We conclude this Account by outlining the future directions to further promote the practical application of PLNPs. The novel protocols for the synthesis of small-size, monodisperse, and water-soluble PLNPs with high NIR PL intensity and superlong afterglow are the vibrant directions for the biomedical applications of PLNPs. In-depth theories and evidence on luminescence mechanism of PLNPs are highly desired for further improvement of their luminescence performance. Furthermore, other irradiations without tissue penetrating depth limit, such as X-ray, are encouraged for use in energy storage and re-excitation of PLNPs, enabling imaging in deep tissue in vivo and integrating other X-ray sensitized theranostic techniques such as computed tomography imaging and radiotherapy. Last but not least, PLNPs-based nanoprobes and the brand new hybrids of PLNPs with other nanomaterials show a bright prospect for accurate diagnosis and efficient treatment of diseases besides tumors.
3D printing is gaining prospects thanks to the ease of manufacturing energy storage devices with programmable geometry at the macro‐ and microscales. Herein, a direct ink writing 3D printing approach ...for preparing all‐printed flexible micro‐supercapacitors is demonstrated using rationally designed poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)/MXene composite gels as inks without the tedious processes and toxic organic additives. Among the printable inks, the homogeneously distributed MXene nanosheets can boost the printability of PEDOT:PSS solution and also regulate the interconnected electronic structures of the PEDOT:PSS undergoing a micellar to linear structure transition. The resulting 3D printed micro‐supercapacitors and integrated devices can deliver exceptionally large areal capacitances, remarkable rate performance, and high cycling stability with thickness‐independent capacitances even under exceptional deformations and low temperatures. This study thus provides a simple yet environmental‐friendly approach for preparing the conducting‐polymer‐based inks for 3D printing of customized, multiscale, and integrated energy devices.
A direct‐ink‐write 3D printing approach for preparing all‐printed flexible micro‐supercapacitors is presented by using rationally designed poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate/MXene composite gels as the printing ink. The 3D printed micro‐supercapacitors and their integrated devices can deliver exceptionally large areal capacitances, remarkable rate performance, and high cycling stability with thickness‐independent capacitances even under exceptional deformations and low temperatures.
The unique features of high porosity, shape selectivity, and multiple active sites make metal–organic frameworks (MOFs) promising as novel stationary phases for high‐performance liquid chromatography ...(HPLC). However, the wide particle size distribution and irregular shape of conventional MOFs lead to lower column efficiency of such MOF‐packed columns. Herein, the fabrication of monodisperse MOF@SiO2 core–shell microspheres as the stationary phase for HPLC to overcome the above‐mentioned problems is reported. Zeolitic imidazolate framework 8 (ZIF‐8) was used as an example of MOFs due to its permanent porosity, uniform pore size, and exceptional chemical stability. Unique carboxyl‐modified silica spheres were used as the support to grow the ZIF‐8 shell. The fabricated monodisperse ZIF‐8@SiO2 packed columns (5 cm long × 4.6 mm i.d.) show high column efficiency (23 000 plates m−1 for bisphenol A) for the HPLC separation of endocrine‐disrupting chemicals (bisphenol A, β‐estradiol, and p‐(tert‐octyl)phenol) and pesticides (thiamethoxam, hexaflumuron, chlorantraniliprole, and pymetrozine) within 7 min with good relative standard deviations for 11 replicate separations of the analytes (0.01–0.39, 0.65–1.7, 0.70–1.3, and 0.17–0.91 % for retention time, peak area, peak height, and half peak width, respectively). The ZIF‐8@SiO2 microspheres combine the advantages of the good column packing properties of the uniform monodisperse silica microspheres and the separation ability of the ZIF‐8 crystals.
Core strength: Monodisperse ZIF‐8@SiO2 (ZIF‐8=zeolitic imidazolate framework 8) core–shell microspheres have been fabricated through controllable growth of a ZIF‐8 shell on spherical carboxylate‐terminated SiO2 cores (see figure). The metal–organic framework material is suitable as a stationary phase for fast and highly efficient HPLC separation.
Covalent organic frameworks (COFs) are a novel class of porous materials, and offer great potential for various applications. However, the applications of COFs in chiral separation and chiral ...catalysis are largely underexplored due to the very limited chiral COFs available and their challenging synthesis. Here we show a bottom-up strategy to construct chiral COFs and an in situ growth approach to fabricate chiral COF-bound capillary columns for chiral gas chromatography. We incorporate the chiral centres into one of the organic ligands for the synthesis of the chiral COFs. We subsequently in situ prepare the COF-bound capillary columns. The prepared chiral COFs and their bound capillary columns give high resolution for the separation of enantiomers with excellent repeatability and reproducibility. The proposed strategy provides a promising platform for the synthesis of chiral COFs and their chiral separation application.
We herein report a monomer-mediated in situ growth strategy for the controllable construction of porous nanospheres with a magnetic core and a tunable COF shell. The composite exhibits high stability ...and excellent performance for the removal of a typical class of endocrine-disrupting chemicals, bisphenol chemicals, in aqueous solution.
The unusual properties such as high surface area, good thermal stability, uniform structured nanoscale cavities and the availability of in-pore functionality and outer-surface modification make ...metal-organic frameworks (MOFs) attractive for diverse analytical applications. However, integration of MOFs with magnets for magnetic solid-phase extraction for analytical application has not been attempted so far. Here we show a facile magnetization of MOF MIL-101(Cr) for rapid magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. MIL-101 is attractive as a sorbent for solid-phase extraction of pollutants in aqueous solution due to its high surface area, large pores, accessible coordinative unsaturated sites, and excellent chemical and solvent stability.
In situ
magnetization of MIL-101 microcrystals as well as magnetic solid-phase extraction of PAHs was achieved simultaneously by simply mixing MIL-101 and silica-coated Fe
3
O
4
microparticles in a sample solution under sonication. Such MOF-based magnetic solid-phase extraction in combination with high-performance liquid chromatography gave the detection limits of 2.8-27.2 ng L
−1
and quantitation limits of 6.3-87.7 ng L
−1
for the PAHs. The relative standard deviations for intra- and inter-day analyses were in the range of 3.1-8.7% and 6.1-8.5%, respectively. The results showed that hydrophobic and π-π interactions between the PAHs and the framework terephthalic acid molecules, and the π-complexation between PAHs and the Lewis acid sites in the pores of MIL-101 play a significant role in the adsorption of PAHs.
Metal-organic framework MIL-101(Cr) microcrystals were magnetized and explored for rapid magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.
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