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•A two-photon probe TPFP for lysosome-targetable HClO detection is developed.•The TPFP exhibits fast response time, high selectivity and low detection limit.•The TPFP can be used for ...two-photon intracellular HClO detection.
The design of robust tools for hypochlorous acid (HClO) detection at subcellular level is highly desired for the better understanding of its biological function in cellular signaling pathways. Herein, we report the development of a two-photon fluorescent probe (TPFP) for lysosome-targetable HClO detection through the integration of a lysosome-targetable group (aminoethyl)morpholine, two-photon fluorophore 1,8-naphthalimide and HClO capturing phenyl-thiourea together. In the presence of HClO, the thiourea moiety is oxidized to urea and thereby restores the fluorescence of 1,8-naphthalimide(at 538nm) due to the inhibition of photo-induced electron transfer (PET) effect. As is demonstrated in the spectroscopic characterizations, the probe TPFP exhibits excellent probing performance toward HClO, including short response time (<30s), outstanding selectivity, high photostability and low detection limit (∼5.7nM). In addition, it is confirmed that TPFP displays promising cell-membrane permeability and high specificity toward HClO in lysosomes through the one-photon and two-photon intracellular fluorescent microscopic imaging experiments. As a consequence, this lysosome-targetable two-photon fluorescent probe provides a promising platform for HClO detection at subcellular level and would inspire the design of plummy tools for other analytes detection.
An AIE-based fluorescent nanoprobe (MTPE-M) has been developed and used for ratiometric detection of hypochlorite with high selectivity and sensitivity. More importantly, its application in live ...cells and zebrafish for ratiometric imaging of endogenous ClO(-) has also been achieved.
Switchable organic fluorescent materials are attracting much interest in many fields including flexible display, information storage, anti‐counterfeit, and bioimaging, due to their prominent ...properties and relatively low cost. Herein, a class of novel photoswitchable fluorescent polymeric nanoparticles (PFPNs) toolbox that shows switchable full‐colored emission including white light is described. This nanoparticles toolbox consists of a series of reversibly photoswitchable and non‐PFPNs with red, green, and blue fluorescence, and is built up from three primary fluorescent dyes and a photochromic diarylethene molecule, through a facile one‐pot miniemulsion method. The as‐prepared PFPNs display the merits of high fluorescence resonance energy transfer efficiency and fluorescence quantum yield, rapid responsiveness, prominent photoreversibility, and brilliant long‐term fluorescence stability (≈6 weeks). They enable switchable emission between white light and any visible color on‐demand in both solution and film states. Their potential in complex fluorescent encryption and photoswitchable white light‐emitting diode is described and its great potential in anti‐counterfeiting technology, data encryption, and the next generation of optoelectronic materials is foreseen.
A full‐colored photoswitchable fluorescent polymeric nanoparticle (PFPN) toolbox is built up via the preparation of a series of reversibly photoswitchable and non‐PFPNs based on three primary fluorescent dyes and a photochromic diarylethene molecule. By varying the mixture ratio of the nanoparticles, the mixed PFPNs‐based nanoparticle solution or film displays photoswitchable fluorescence from white‐light to full‐colored fluorescence.
This paper presents the development of a photoelectrochemical sensor for hypochlorous acid (HOCl) detection, employing a phenothiazine-based organic photosensitizer (Dye-PZ). The designed probe, ...Dye-PZ, follows a D-π-A structure with phenothiazine as the electron-donating group and a cyano-substituted pyridine unit as the electron-accepting group. A specific reaction of the phenothiazine sulfur atom with HOCl enables selective recognition. The covalent immobilization of Dye-PZ onto a titanium dioxide nanorod-coated fluorine-doped tin oxide electrode (FTO/TiO
) using bromo-silane coupling agent (BrPTMS) resulted in the fabrication of the photoanode FTO/TiO
/BrPTMS/Dye-PZ. The photoanode exhibited a significant photoresponse under visible-light irradiation, with a subsequent reduction in photocurrent upon reaction with HOCl. The oxidation of the phenothiazine sulfur atom to a sulfoxide diminished the internal charge transfer (ICT) effect. Leveraging this principle, the successful photoelectrochemical sensing of HOCl was achieved. The sensor showed high stability, excellent reproducibility, and selective sensitivity for HOCl detection. Our study provides a novel approach for the development of efficient photoelectrochemical sensors based on organic photosensitizers, with promising applications in water quality monitoring and biosensing.
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•A polymer nanoparticle-based ratiometric fluorescent probe (PN) for selectively detecting Hg2+ has been developed.•The probe shows good water dispersibility, excellent long-term ...photostability and low cytotoxicity.•The detection limit of probe is 75nM.•The probe can be used to image Hg2+ in living cells.
Mercury pollutant brings huge threat to human health and the environment because of its bioaccumulation and permanent damage. Thus, highly selective and ratiometric detection and imaging of Hg2+ in organisms is quite important. Herein, we report on a polymer nanoparticle-based ratiometric fluorescent probe (NP3) for highly selective recognition of Hg2+ in totally aqueous solution and imaging in living cells. This probe comprises the reference fluorescent dye (4-ethoxy-9-allyl-1,8-naphthalimide: EANI), which resides in the core of nanoparticle, and the Hg2+-recognition group (fluorescein derivative: AEMH-FITC) on the surface of nanoparticle. It displays distinct dual emissions at 432nm and 528nm under a single-wavelength excitation. The fluorescence of the FITC moieties can be effectively quenched by Hg2+ due to photoinduced electron transfer (PET) mechanism, while that of the EANI remains constant, resulting in a ratiometric fluorescent detection of Hg2+. The as-prepared NP3 not only shows favorable water dispersibility, excellent long-term photostability, but also exhibits highly selective ratiometric detection of Hg2+ over other interfering ions (such as Cu2+, Na+, Mg2+, Zn2+, Co2+, Mn2+, K+, Ca2+, Fe3+, Cd2+, Ag+, Fe2+), and quite low detection limit (∼75nM). Furthermore, intracellular fluorescence imaging experiments demonstrate that NP3 has good permeability of cell-membrane, and is able to facilitate visualization of Hg2+ changes in living cells.
Red carbon dots (RCD) are reported as label-free two-photon fluorescent nanoprobes for detecting and imaging of FA. This nanoprobe features excellent selectivity, good cell-membrane permeability and ...biocompatibility, as well as the large two-photon absorption cross-section. In addition, RCD have been applied for monitoring FA in live cells and zebrafishes with OPM and TPM.
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Direct, in situ selective detection of intracellular formaldehyde (FA) is of great significance for understanding its function in FA-related diseases. Herein, red carbon dots (RCD) are reported as label-free two-photon fluorescent nanoprobes for detecting and imaging of FA. Upon addition of FA, the -NH2 groups of RCD could quickly and specially react with aldehydes to form Schiff base and then the strong fluorescence of RCD with blue-shift emission is recovery due to the destruction of the hydrogen bond interaction between RCD and water. In addition, the nanoprobes exhibit outstanding photostability, rapid response (<1 min), high sensitivity (∼9.9 μmol/L) and excellent selectivity toward FA over other aldehyde group compounds. Notably, owing to the good cell-membrane permeability and biocompatibility, as well as the large two-photon absorption cross-section, the as-prepared RCD can be used as label-free nanoprobes for selectively detecting and imaging FA in living cells and zebrafishes through one-photon and two-photon excitation. Moreover, RCD could stain the tissue of zebrafishes at depths interval of up to 240 μm under two-photon excitation. This research implied that RCD are promising tools for directly and in situ imaging FA in vivo, thus providing critical insights into FA-related pathophysiological processes.
Rodents, as the most diverse and widest distributed mammals, are a natural reservoir of many zoonotic viruses. However, little is known about the viral diversity harbored by rodents in China. Here we ...performed viral metagenomic analyses of 314 wild rodents covering 7 species, sampled in North-western China. We also conducted a systematic virological characterization of a new Wenzhou virus (WENV) isolate, QARn1, from a brown rat (Rattus norvegicus). Full genomic and phylogenetic analyses showed that QARn1 is a previously unidentified strain of Wenzhou mammarenavirus and forms a new branch within the Asian clade. Experimental infection of Sprague-Dawley rats with QARn1 did not present overt pathology, but specific humoral immune responses developed and mild hemorrhage and immunocyte infiltration of the lungs and thymus were observed. These observations have expanded the geographic distribution of WENV to Central Asia, and further confirm that brown rats are natural hosts of Wenzhou virus.
•Viral metagenomic analysis was performed on rodents collected in Xinjiang, China.•A new strain of Wenzhou virus, QARn1, was identified in a wild brown rat.•The geographic distribution of Wenzhou virus has been expanded to Central Asia region.•Experimentally infection of QARn1 showed brown rats are natural host of this virus.
Abstract Combinatorial use of iron oxide nanoparticles (IONPs) and an alternating magnetic field (AMF) can induce local hyperthermia in tumors in a controlled and uniform manner. Heating B16 primary ...tumors at 43 °C for 30 min activated dendritic cells (DCs) and subsequently CD8+ T cells in the draining lymph node (dLN) and conferred resistance against rechallenge with B16 (but not unrelated Lewis Lung carcinoma) given 7 days post hyperthermia on both the primary tumor side and the contralateral side in a CD8+ T cell-dependent manner. Mice with heated primary tumors also resisted rechallenge given 30 days post hyperthermia. Mice with larger heated primary tumors had greater resistance to secondary tumors. No rechallenge resistance occurred when tumors were heated at 45 °C. Our results demonstrate the promising potential of local hyperthermia treatment applied to identified tumors in inducing anti-tumor immune responses that reduce the risk of recurrence and metastasis. From the Clinical Editor Local heating of tumors via iron oxide NPs and an alternating magnetic field led to activation of anti-cancer CD8 T cells, which resulted in resistance against re-challenge and greater resistance to secondary tumors. Similar local heating-based strategies may become an important weapon in enhancing tumor elimination via a naturally existing but attenuated immune response.
Previous studies found minimal evidence and raised controversy about the link between hemoglobin and 28-day mortality in sepsis patients. As a result, the purpose of this study was to examine the ...association between hemoglobin and 28-day death in sepsis patients by analyzing the Medical Intensive Care IV (MIMIC-IV) database from 2008 to 2019 at an advanced medical center in Boston, Massachusetts.
We extracted 34,916 sepsis patients from the MIMIC-IV retrospective cohort database, using hemoglobin as the exposure variable and 28-day death as the outcome variable, and after adjusting for confounders (demographic indicators, Charlson co-morbidity index, SOFA score, vital signs, medication use status (glucocorticoids, vasoactive drugs, antibiotics, and immunoglobulins, etc.)), we investigated the independent effects of hemoglobin and 28-day risk of death by binary logistic regression as well as two-piecewise linear model, respectively.
Hemoglobin levels and 28-day mortality were shown to be non-linearly related.The inflection points were 104 g/L and 128 g/L, respectively. When HGB levels were between 41 and 104 g/L, there was a 10% decrease in the risk of 28-day mortality (OR: 0.90; 95% CI: 0.87 to 0.94, p-value = 0.0001). However, in the range of 104-128 g/L, we did not observe a significant association between hemoglobin and 28-day mortality (OR: 1.17; 95% CI: 1.00 to 1.35, P value = 0.0586). When HGB was in the range of 128-207 g/L, there was a 7% increase in the risk of 28-day mortality for every 1 unit increase in HGB (OR: 1.07; 95% CI: 1.01 to 1.15, P value = 0.0424).
In patients with sepsis, baseline hemoglobin was related to a U-shaped risk of 28-day death. When HGB was in the range of 12.8-20.7 g/dL, there was a 7% increase in the risk of 28-day mortality for every 1 unit increase in HGB.
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•A fluorescent BCNs was developed for screening of TYR activity and its inhibitors.•The BCNs exhibit high brightness, excellent photostability and biocompatibility.•The BCNs-based ...detection platform shows ultrahigh sensitivity and selectivity.
It is of great value to develop a simple, rapid, label-free and sensitive strategy for tyrosinase activity detection and corresponding inhibitor screening in both biomedical diagnosis and cosmetic industry. However, many recently reported fluorescent assays may suffer from instability to light irradiation, poor water solubility, and complex modification. Herein, a novel fluorescent biosensor strategy has been developed capable of sensitive, label-free and rapid screening of tyrosinase activity as well as corresponding inhibitors based on fluorescent block copolymer nanoparticles (BCNs). The reported BCNs were prepared by coprecipitation assay using the mixture of amphiphilic block copolymer and fluorescent conjugated polymer, which show many advantages including high brightness, excellent photostability and biocompatibility, enabling the biosensor with high sensitivity and good reproducibility in a single-step operation. The reported assay exhibited high sensitivity and selectivity with a detection limit of 1.5 ng/mL for tyrosinase (TRY) activity detection and hold potential in its inhibitor screening. The satisfying recoveries offered great potential for complicated sample analysis. Hence, this reported assay may provide a novel platform for biosensor development.
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