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Chemical modifications in RNAs play crucial roles in diversifying their structures and regulating numerous biochemical processes. Since the 1990s, several hydrophobic prenyl-modifications have been discovered in various RNAs. Prenyl groups serve as precursors for terpenes and many other biological molecules. The processes of prenylation in different macromolecules have been extensively studied. We introduce here a novel chemical biology toolkit that not only labels i6A, a prenyl-modified RNA residue, by leveraging the unique reactivity of the prenyl group, but also provides a general strategy to incorporate fluorescence functionalities into RNAs for molecular tracking purposes. Our findings revealed that iodine-mediated cyclization reactions of the prenyl group occur rapidly, transforming i6A from a hydrogen-bond acceptor to a donor. Based on this reactivity, we developed an Iodine-Mediated Cyclization and Reverse Transcription (IMCRT) tRNA-seq method, which can profile all nine endogenous tRNAs containing i6A residues in Saccharomyces cerevisiae with single-base resolution. Furthermore, under stress conditions, we observed a decline in i6A levels in budding yeast, accompanied by significant decrease of mutation rate at A37 position. Thus, the IMCRT tRNA-seq method not only permits semi-quantification of i6A levels in tRNAs but also holds potential for transcriptome-wide detection and analysis of various RNA species containing i6A modifications.
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Isopenteniladenosina , Processamento Pós-Transcricional do RNA , RNA de Transferência , Iodo , Neopreno , RNA de Transferência/metabolismo , Saccharomyces cerevisiae , Análise de Sequência de RNARESUMO
The development of appropriate molecular tools to monitor different mercury speciation, especially CH3Hg+, in living organisms is attractive because its persistent accumulation and toxicity are very harmful to human health. Herein, we develop a novel activity-based ratiometric SERS nanoprobe to selectively monitor Hg2+ and CH3Hg+ in aqueous media and in vivo. In this nanoprobe, a new bifunctional Raman probe bis-s-s'-[(s)-(4-(ethylcarbamoyl)phenyl)boronic acid] (b-(s)-EPBA) was synthesized and immobilized on the surface of gold nanoparticles via a Au-S bond, in which the phenylboronic acid group was employed as the recognition unit for Hg2+ and CH3Hg+ based on the Hg-promoted transmetalation reaction. In the presence of Hg2+ and CH3Hg+, a new surface-enhanced Raman scattering (SERS) peak aroused from of C-Hg appeared at 1080 cm-1, and the SERS intensity at 1002 cm-1 belonged to the B-O symmetric stretching decreased simultaneously. The quantitative tracking of Hg2+ and CH3Hg+ was realized based on the SERS intensity ratio (I1080/I1303) with rapid response (â¼4 min) and high sensitivity, with detection limits of 10.05 and 25.13 nM, respectively. Moreover, the SERS sensor was used for the quantitative detection of Hg2+ and CH3Hg+ in four actual water samples with a high accuracy and excellent recovery. More importantly, cell imaging experiments showed that AuNPs@b-(s)-EPBA could quantitatively detect intracellular CH3Hg+ and had a good concentration dependence in ratiometric SERS imaging. Meanwhile, we demonstrated that AuNPs@b-(s)-EPBA could detect and image CH3Hg+ in zebrafish. We anticipate that AuNPs@b-(s)-EPBA could potentially be used to study the physiological functions related to CH3Hg+ in the future.
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Ferroptosis is an iron-dependent programmed cell death that is characterized by the dysregulation of lipid reactive oxygen species (ROS) production, causing abnormal changes in hypochlorous acid (HClO) levels in lysosomes. Super-resolution imaging can observe the fine structure of the lysosome at the nanometer level; therefore, it can be used to detect lysosome HClO levels during ferroptosis at the suborganelle level. Herein, we utilize a ratiometric fluorescent probe, SRF-HClO, for super-resolution imaging of lysosome HClO. Structured-illumination microscopy (SIM) improves the accuracy of lysosome targeting and enables the probe SRF-HClO to be successfully applied to rapidly monitor the up-regulated lysosome HClO at the nanoscale during inflammation and ferroptosis. Importantly, the probe SRF-HClO can also detect HClO changes in inflammatory and ferroptosis mice and evaluate the inhibitory effect of ferroptosis on mice tumors.
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Ferroptose , Corantes Fluorescentes , Ácido Hipocloroso , Lisossomos , Ferroptose/efeitos dos fármacos , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Ácido Hipocloroso/metabolismo , Lisossomos/química , Lisossomos/metabolismo , Animais , Camundongos , Humanos , Imagem Óptica , Células RAW 264.7RESUMO
Mitochondria are important organelles that provide energy for cellular physiological activities. Changes in their structures may indicate the occurrence of diseases, and the super-resolution imaging of mitochondria is of great significance. However, developing fluorescent probes for mitochondrial super-resolution visualization still remains challenging due to insufficient fluorescence brightness and poor stability. Herein, we rationally synthesized an ultrabright xanthene fluorescence probe Me-hNR for mitochondria-specific super-resolution imaging using structured illumination microscopy (SIM). The rigid structure of Me-hNR provided its ultrahigh fluorescence quantum yield of up to 0.92 and ultrahigh brightness of up to 16,000. Occupying the para-position of the O atom in the xanthene skeleton by utilizing the smallest methyl group ensured its excellent stability. The study of the photophysical process indicated that Me-hNR mainly emitted fluorescence via radiative decay, and nonradiative decay and inter-system crossing were rare due to the slow nonradiative decay rate and large energy gap (ΔEst = 0.55 eV). Owing to these excellent merits, Me-hNR can specifically light up mitochondria at ultralow concentrations down to 5 nM. The unprecedented spatial resolution for mitochondria with an fwhm of 174 nm was also achieved. Therefore, this ultrabright xanthene fluorescence probe has great potential in visualizing the structural changes of mitochondria and revealing the pathogenesis of related diseases using SIM.
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Corantes Fluorescentes , Xantenos , Corantes Fluorescentes/química , Mitocôndrias , Organelas , Microscopia de Fluorescência/métodosRESUMO
Analyzing trace-level volatile organic compounds (VOCs) remains challenging due to initial sampling and preconcentration limitations. Inspired by the highly reproducible and constantly renewable electrode surface of dropping mercury electrode (DME), a contactless enrichment process was first reported by using an acoustic levitation device to trap and concentrate VOCs from gas samples onto suspended droplets, which were then directly transferred into gas chromatography-mass spectrometry (GC-MS) for real-time analysis. Compared with traditional methods injection methods, this method achieves a 46-fold increase in nicotine peak area. The detection sensitivity was enhanced significantly, attributed to the high specific surface area of the droplets and the accelerating extraction vibration. Notably, the number of identified VOCs from burning cigarettes significantly increased from 17 to 212, including 22 aromatic compounds with distinct aromas. The remarkable versatility of this method was demonstrated by effectively monitoring the dynamic changes of 16 VOCs in environmental tobacco smoke (ETS) following cigarette burning, revealing the persistence of these compounds, even after 40 min. Moreover, directly analyzing human-exhaled aerosol found that nicotine rapidly decreased while its metabolite cotinine increased, showcasing the potential for tracking human metabolism and behavior in vivo. Furthermore, multivariate data analysis of VOC profiles from six cigarette brands allowed for their visual differentiation. With versatility, sensitivity, and the ability to distinguish trace-level VOCs in realtime, this method offers promising avenues for environmental monitoring, metabolic studies, and various analytical applications.
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In this work, we develop a dual recycling amplification aptasensor for sensitive and rapid detection of lead ions (Pb2+) using fluorescence and surface-enhanced Raman scattering (FL-SERS). The aptasensor allows targeted cleavage of substrates through specifically binding with the Pb2+-dependent aptamer (M-PS2.M). Ultrasensitive detection of trace Pb2+ has been achieved using an enzyme-free nonlinear hybridization chain reaction (HCR) and the FL-SERS technique. The lower limit of detection (LOD = 3σ/k) is 0.115 pM in FL mode and 1.261 fM in SERS mode. The aptasensor is characterized by high reliability and specificity, among other things, to distinguish Pb2+ from other metal ions. In addition, the aptasensor can detect Pb2+ in actual water with good recovery. Compared with the single-mode aptasensor, the dual-mode aptasensor is characterized by high reliability, an extensive detection range, and high specificity.
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Nanozymes, as an emerging class of enzyme mimics, have attracted much attention due to their adjustable catalytic activity, low cost, easy modification, and good stability. Researchers have made great efforts in developing and applying high-performance nanozymes. Recently, transition-metal-based nanozymes have been designed and widely developed because they possess unique photoelectric properties and high enzyme-like catalytic activities. To highlight these achievements and help researchers to understand the research status of transition-metal-based nanozymes, the development of transition-metal-based nanozymes from material characteristics to biological applications is summarized. Herein, we focus on introducing six categories of transition-metal-based nanozymes and highlight their progress in biomarker sensing and catalytic therapy for tumors. We hope that this review can guide the further development of transition-metal-based nanozymes and promote their practical applications in cancer diagnosis and treatment.
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The investigation into viable but non-culturable (VBNC) bacteria through the implementation of resuscitation promoting factors (Rpfs) has broadened the potential sources for isolating strains capable of degrading polychlorinated biphenyls (PCBs). Nonetheless, there has been limited research on the efficacy of resuscitated strains and the potential improvement of their performance through co-cultivation. In this work, the PCB degradation potential of resuscitated strains, specifically Pseudomonas sp. HR1 and Achromobacter sp. HR2, as well as their co-cultures, was investigated. Of particular importance was the comparative analysis between the optimal co-culture and individual strains regarding their ability to degrade PCB homologs and mineralize intermediate metabolites. The results suggested that the resuscitated strains HR1 and HR2 demonstrated robust growth and effective degradation of Aroclor 1242. The co-culture CO13, with an optimal HR1 to HR2 ratio of 1:3, exhibited a remarkable improvement in PCB degradation and intermediate metabolite mineralization compared to individual strains. Analysis of functional genes and degradation metabolites revealed that both the individual strains and co-culture CO13 degraded PCBs via the HOPDA-benzoate pathway, then mineralized through protocatechuate meta- and ortho-cleavage pathways, as well as the catechol ortho-cleavage pathway. This study represents the first documentation of the improved PCB degradation through the co-cultivation of resuscitated strains, which highlights the great promise of these resuscitated strains and their co-cultures as effective bio-inoculants for enhanced bioremediation.
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Herein, a magnetic borate-functionalized MXene composite with multiple boronic affinity sites was fabricated by embedding Fe3 O4 nanoparticles with 4-formylphenylboronic acid functionalized Ti3 C2 Tx nanosheets and served as sorbent for the simultaneous extraction of catecholamines (CAs) in urine samples. The morphology and structure of the magnetic materials were investigated using scanning microscopy, vibrating sample magnetometer, X-ray photoelectron spectrometer, and X-ray diffraction. The introduction of polyethyleneimine can amplify the bonded boronic acid groups, thereby effectively improving the adsorption capacities for CAs based on the multiple interactions of boronic affinity, hydrogen bonding, and metal coordination. The adsorption performance was investigated using the kinetics and isotherms models, and the main parameters that influence the extraction efficiency were optimized. Under the most favorable magnetic solid-phase extraction condition, a sensitive method for the analysis of CAs in urine samples was developed by combining magnetic solid-phase extraction conditions with high-performance liquid chromatography detection. The findings illustrated that the proposed approach possessed a wide linearity range of 0.05-250 ng/mL with an acceptable correlation coefficient (R2 ≥ 0.9984) and detection limits of 0.010-0.015 ng/mL for the target CAs. The research not only provides a notable composite with multiple boronic affinity sites but also offers an effective and feasible measure for the detection of CAs in biological samples.
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Catecolaminas , Nanopartículas de Magnetita , Nitritos , Elementos de Transição , Polietilenoimina/química , Adsorção , Ácidos Borônicos/química , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida , Nanopartículas de Magnetita/química , Fenômenos MagnéticosRESUMO
BACKGROUND: The Cisternostomy is a novel surgical concept in the treatment of Traumatic Brain Injury (TBI), which can effectively drain the bloody cerebrospinal fluid from the skull base cistern, reduce the intracranial pressure, and improve the return of bone flap, but its preventive role in post-traumatic hydrocephalus (PTH) is unknow. The purpose of this paper is to investigate whether Cisternostomy prevents the occurrence of PTH in patients with moderate and severe TBI. METHODS: A retrospective analysis of clinical data of 86 patients with moderate and severe TBI from May 2019 to October 2021 was carried out in the Brain Trauma Center of Tianjin Huanhu Hospital. Univariate analysis was performed to examine the gender, age, preoperative Glasgow Coma Scale (GCS) score, preoperative Rotterdam CT score, decompressive craniectomy rate, intracranial infection rate, the incidence of subdural fluid, and incidence of hydrocephalus in patients between the Cisternostomy group and the non-Cisternostomy surgery group. we also analyzed the clinical outcome indicators like GCS at discharge,6 month GOS-E and GOS-E ≥ 5 in two groups.Additionaly, the preoperative GCS score, decompressive craniectomy rate, age, and gender of patients with PTH and non hydrocephalus were compared. Further multifactorial logistic binary regression was performed to explore the risk factors for PTH. Finally, we conducted ROC curve analysis on the statistically significant results from the univariate regression analysis to predict the ability of each risk factor to cause PTH. RESULTS: The Cisternostomy group had a lower bone flap removal rate(48.39% and 72.73%, p = 0.024)., higer GCS at discharge(11.13 ± 2.42 and 8.93 ± 3.31,p = 0.000) and better 6 month GOS-E(4.55 ± 1.26 and 3.95 ± 1.18, p = 0.029)than the non-Cisternostomy group However, there was no statistical difference in the incidence of hydrocephalus between the two groups (25.81% and 30.91%, p = 0.617). Moreover, between the hydrocephalus group and no hydrocephalus group,there were no significant differences in the incidence of gender, age, intracranial infection, and subdural fluid. While there were statistical differences in peroperative GCS score, Rotterdam CT score, decompressive craniectomy rate, intracranial infection rate, and the incidence of subdural fluid in the two groups, there was no statistical difference in the percentage of cerebral cisterns open drainage between the hydrocephalus group and no hydrocephalus group (32.00% and 37.70%, p = 0.617). Multifactorial logistic binary regression analysis results revealed that the independent risk factors for PTH were intracranial infection (OR = 18.460, 95% CI: 1.864-182.847 p = 0.013) and subdural effusion (OR = 10.557, 95% CI: 2.425-35.275 p = 0.001). Further, The ROC curve analysis showed that peroperative GCS score, Rotterdam CT score and subdural effusion had good ACU(0.785,0.730,and 0.749), with high sensitivity and specificity to predict the occurrence of PTH. CONCLUSIONS: Cisternostomy may decrease morbidities associated with removal of the bone flap and improve the clinical outcome, despite it cannot reduce the disability rate in TBI patients.Intracranial infection and subdural fluid were found to be the independent risk factors for PTH in patients with TBI,and the peroperative GCS score, Rotterdam CT score and subdural effusion had higher sensitivity and specificity to predict the occurrence of PTH. And more importantly, no correlation was observed between open drainage of the cerebral cisterns and the occurrence of PTH, indicating that Cisternostomy may not be beneficial in preventing the occurrence of PTH in patients with moderate and severe TBI.
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Lesões Encefálicas Traumáticas , Hidrocefalia , Humanos , Masculino , Feminino , Lesões Encefálicas Traumáticas/cirurgia , Lesões Encefálicas Traumáticas/complicações , Pessoa de Meia-Idade , Adulto , Hidrocefalia/cirurgia , Hidrocefalia/etiologia , Hidrocefalia/prevenção & controle , Estudos Retrospectivos , Craniectomia Descompressiva/métodos , Idoso , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/epidemiologia , Adulto Jovem , Escala de Coma de GlasgowRESUMO
Extreme weather poses huge challenges for animals that must adapt to wide variations in environmental temperature and, in many cases, it can lead to the local extirpation of populations or even the extinction of an entire species. Previous studies have found that one element of amphibian adaptation to environmental stress involves changes in mitochondrial gene expression at low temperatures. However, to date, comparative studies of gene expression in organisms living at extreme temperatures have focused mainly on nuclear genes. This study sequenced the complete mitochondrial genomes of five Asian hylid frog species: Dryophytes japonicus, D. immaculata, Hyla annectans, H. chinensis and H. zhaopingensis. It compared the phylogenetic relationships within the Hylidae family and explored the association between mitochondrial gene expression and evolutionary adaptations to cold stress. The present results showed that in D. immaculata, transcript levels of 12 out of 13 mitochondria genes were significantly reduced under cold exposure (p < 0.05); hence, we put forward the conjecture that D. immaculata adapts by entering a hibernation state at low temperature. In H. annectans, the transcripts of 10 genes (ND1, ND2, ND3, ND4, ND4L, ND5, ND6, COX1, COX2 and ATP8) were significantly reduced in response to cold exposure, and five mitochondrial genes in H. chinensis (ND1, ND2, ND3, ND4L and ATP6) also showed significantly reduced expression and transcript levels under cold conditions. By contrast, transcript levels of ND2 and ATP6 in H. zhaopingensis were significantly increased at low temperatures, possibly related to the narrow distribution of this species primarily at low latitudes. Indeed, H. zhaopingensis has little ability to adapt to low temperature (4 °C), or maybe to enter into hibernation, and it shows metabolic disorder in the cold. The present study demonstrates that the regulatory trend of mitochondrial gene expression in amphibians is correlated with their ability to adapt to variable climates in extreme environments. These results can predict which species are more likely to undergo extirpation or extinction with climate change and, thereby, provide new ideas for the study of species extinction in highly variable winter climates.
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Anuros , Genoma Mitocondrial , Filogenia , Animais , Anuros/genética , Anuros/fisiologia , Resposta ao Choque Frio/genética , Temperatura Baixa , Adaptação Fisiológica/genética , Regulação da Expressão GênicaRESUMO
Resuscitation promoting factors (Rpfs), known for their anti-dormancy cytokine properties, have been extensively investigated in the medical field. Although the Rpf from Micrococcus luteus has been successfully utilized to resuscitate and stimulate microbial populations for the degradation of polychlorinated biphenyls (PCBs), the presence of indigenous Rpf homologs in PCB-contaminated soils has not been established. In this study, the distribution characteristics of rpf-like genes and indigenous strain capable of producing Rpf in PCB-contaminated soils were explored. The results revealed the widespread presence of Rpf-like domains and their associated genes, particularly in close association with heavy metals and PCBs. The rpf-like genes were predominantly found in Proteobacteria and displayed a positive correlation with genes involved in PCB degradation and viable but non-culturable (VBNC) formation. Notably, the recombinant Rpf-Ac protein derived from the indigenous strain Achromobacter sp. HR2 exhibited muralytic activity and demonstrated significant efficacy in resuscitating the growth of VBNC cells, while also stimulating the growth of normal cells. These findings shed light on the prevalent presence of Rpf homologs in PCB-contaminated soils and their potential to resuscitate functional populations in the VBNC state, thereby enhancing in situ bioremediation.
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Bifenilos Policlorados , Biodegradação Ambiental , SoloRESUMO
Sulfur-driven autotrophic denitrification (S0dAD) was employed to remove residual nitrogen from the biological effluent of landfill leachate after partial nitrification and denitrification pretreatment. The performance of S0dAD were assessed with various NOx--N (NO2--N and NO3--N) loadings over a 185-day operational period. The results demonstrated that a notable NOx--N removal efficiency of 97.8 ± 2.0% was achieved under nitrogen removal rates of 0.12 ± 0.02 kg N/(m3· d), leading to total nitrogen concentrations of 8.6 ± 3.8 mg/L in the effluent. Batch experiments revealed competitive utilization of nitrogenous electron acceptors, with NO2--N demonstrating 2-4 times higher denitrification rates than NO3--N under coexistence conditions. Genus-level microbial community identified that Thiobacillus and Sulfurovum was highly enriched with as key denitrifying bacteria in the S0dAD system. These findings provide insights for advanced nitrogen removal coupling S0dAD with partial nitrification and denitrification process for landfill leachate treatment.
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Desnitrificação , Nitrificação , Nitrogênio , Enxofre , Poluentes Químicos da Água , Nitrogênio/metabolismo , Enxofre/metabolismo , Poluentes Químicos da Água/metabolismo , Processos AutotróficosRESUMO
Cathodic electrochemiluminesence (ECL) microscopy based on luminol analog L012 was originally established to implement the imaging of a single nanotube and nucleolin on a single tumor cell. This microscopy utilizes multiwalled carbon nanotubes (MWCNTs) as advanced coreactant accelerators to efficiently convert dissolved oxygen (O2) and H2O2 into reactive oxygen species (ROS) due to excellent electrocatalytic properties. The produced ROS could oxide L012 into an excited state of L012 leading to a bright cathodic ECL illumination, thereby promoting ECL imaging of MWCNTs at a low triggering potential. After being modified with AS1411 aptamers, MWCNTs@AS1411 probes were incubated with tumor cells for specific ECL imaging of nucleolin on the plasma membrane, which permits cathodic ECL microscopy for label-free bioassays without ECL tags. The L012-based cathodic ECL microscopy with a moderate operating potential and label-free characteristics provides a universal approach in single nanomaterial and single-cell imaging and analyses.
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Técnicas Biossensoriais , Nanotubos de Carbono , Análise de Célula Única , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Peróxido de Hidrogênio , Medições Luminescentes/métodos , Luminol , Microscopia , Espécies Reativas de Oxigênio , Análise de Célula Única/métodos , NucleolinaRESUMO
Herein, a chemiluminescence (CL) biosensor based on CRISPR-Cas12a and cation exchange reaction was constructed to detect the biomarker microRNA-21 (miRNA-21). The rolling circle amplification (RCA) reaction was introduced to convert each target RNA strand into a long single-stranded DNA with repeated sequences, which acted as triggers to initiate the transcleavage activity of CRISPR-Cas12a. The activated Cas12a could cleave the biotinylated linker DNA of CuS nanoparticles (NPs) to inhibit the binding of CuS NPs to streptavidin immobilized on the surface of the microplate, which strongly reduced the generation of Cu2+ from a cation exchange between CuS NPs and AgNO3, and thus efficiently suppressed the CL of Cu2+-luminol-H2O2 system, giving a "signal off" biosensor. With the multiple amplification, the detection limit of the developed sensor for miRNA-21 reached 16 aM. In addition, this biosensor is not only suitable for a professional chemiluminescence instrument but also for a smartphone used as a detection tool for the purpose of portable and low-cost assay. This method could be used to specifically detect quite a low level of miRNA-21 in human serum samples and various cancer cells, indicating its potential in ultrasensitive molecular diagnostics.
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Técnicas Biossensoriais , MicroRNAs , Humanos , Sistemas CRISPR-Cas/genética , Luminescência , Peróxido de Hidrogênio/química , DNA/genética , MicroRNAs/genética , MicroRNAs/química , Técnicas Biossensoriais/métodosRESUMO
Escherichia coli (E. coli) was used for cancer therapy due to the tumor-targeting, catalytic, and surface-reducing properties. Effective diagnosis combined with treatment of cancer based on E. coli, however, was rarely demonstrated. In this study, E. coli was used to surface reduce HAuCl4 and as a carrier to modify riboflavin (Rf) and luminol (E-Au@Rf@Lum). After targeted delivery to tumor, the E-Au@Rf@Lum probe could actively emit 425 nm blue-violet chemiluminescence (CL) to achieve cell imaging for cancer diagnosis. Furthermore, this light could in situ trigger the photosensitizer (Rf) through CL resonance energy transfer, which produces reactive oxygen species (ROS) for accurate photodynamic therapy. In return, the excessive ROS enhanced the blue-violet light which was further absorbed by Rf, and ROS production was cyclically amplified. Abundant ROS broke down the dense extracellular matrix network and penetrated deep into tumors. Besides, E. coli with excellent catalytic property could decompose H2O2 to O2 to relieve tumor hypoxia for a long time and enhance the photosensitized process of Rf. By self-illumination, effective penetration, and tumor hypoxia relief, this work opens a self-amplified therapy modality to tumor.
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Escherichia coli , Neoplasias , Humanos , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Amplificadores EletrônicosRESUMO
The contamination of surface and ground water by per- and polyfluoroalkyl substances (PFASs) has become a growing concern, and the structural diversity of PFASs is the major challenge for their ubiquitous applications. Strategies for monitoring coexistent anionic, cationic, and zwitterionic PFASs even at trace levels in aquatic environments are urgently demanded for effective pollution control. Herein, novel amide group and perfluoroalkyl chain-functionalized covalent organic frameworks (COFs) named COF-NH-CO-F9 are successfully synthesized and used for highly efficient extraction of broad-spectrum PFASs, attributing to their unique structure and the multifunctional groups. Under the optimal conditions, a simple and high-sensitivity method is established to quantify 14 PFASs including anionic, cationic, and zwitterionic species by coupling solid-phase microextraction (SPME) with ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-MS/MS) for the first time. The established method displays high enrichment factors (EFs) of 66-160, ultrahigh sensitivity with low limits of detection (LODs) of 0.0035-0.18 ng L-1, a wide linearity of 0.1-2000 ng L-1 with correlation coefficient (R2) ≥0.9925, and satisfactory precision with relative standard deviations (RSDs) ≤11.2%. The excellent performance is validated in real water samples with recoveries of 77.1-108% and RSDs ≤11.4%. This work highlights the potential of rational design of COFs with the desired structure and functionality for the broad-spectrum enrichment and ultrasensitive determination of PFASs in real applications.
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The construction of a sensitive strategy for in situ visualizing and dynamic tracing intracellular microRNA is of great importance. Via the toehold-mediated strand displacement process, the catalytic hairpin assembly (CHA) could offer several hundreds-fold signal amplifications. However, the CHA may produce certain background interferences since microRNA may exist in normal cells. In this work, we constructed an endogenously and sequentially activated signal amplification strategy to provide the amplified dual-color fluorescence imaging of microRNA in living cancer cells, which was comprised of two successive reaction processes: the activation of the preprotective catalytic probe by the endogenous glutathione (GSH) and the subsequent catalytic hairpin assembly on the surface of the upconversion nanoprobe triggered by the specific microRNA. Since the concentration of GSH in cancer cells was much higher than that in normal cells and the extracellular environment, the activation of the designed nanoprobe could be controlled at the desirable site. With the merits of the endogenous initiation and selective activation, the designed nanoprobe could achieve the bioimaging of microRNA in living cancer cells with high precision and reliability. Furthermore, via the introduction of a photosensitizer molecule into the DNA strand, the designed nanoplatform could achieve the precise photodynamic therapy (PDT) for cancer cells and malignant tumors under the irradiation of the NIR laser. This work provided a new avenue to achieve the accurate imaging of intracellular microRNA and guided precise PDT, which would offer powerful hints to the early diagnosis and therapy of malignant tumors.
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Técnicas Biossensoriais , MicroRNAs , Neoplasias , Fotoquimioterapia , MicroRNAs/genética , Reprodutibilidade dos Testes , Fármacos Fotossensibilizantes/farmacologia , DNA , Técnicas Biossensoriais/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológicoRESUMO
Since the discovery of graphene, research on the family of 2D materials has been a thriving field. Metal phosphorous chalcogenides (MPX3 ) have attracted renewed attention due to their distinctive physical and chemical properties. The advantages of MPX3 , such as tunable layered structures, unique electronic properties, thermodynamically appropriate band alignments and abundant catalytic active sites on the surface, make MPX3 material great potential in electrocatalysis. In this review, the applications of MPX3 electrocatalysts in recent years, including hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction, are summarized. Structural regulation, chemical doping and multi-material composite that are often effective and practical research methods to further optimize the catalytic properties of these materials, are introduced. Finally, the challenges and opportunities for electrocatalytic applications of MPX3 materials are discussed. This report aims to advance future efforts to develop MPX3 and related materials for electrocatalysis.
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Exploiting effective non-noble metal electrocatalysts for oxygen reduction reaction (ORR) is crucial for fuel cells and metal-air batteries. Herein, we designed and fabricated Co nanoparticles confined in Mo/N co-doped polyhedral carbon frameworks (Co-NP/MNCF) derived from polyoxometalate-encapsuled metal-organic framework, which showed comparable ORR performance with commercial Pt/C and a larger diffusion-limited current density. Moreover, the Co-NP/MNCF also exhibited excellent ORR stability and methanol tolerance. These appealing performances can be attributed to the porosity regulation and heteroatom doping of metal-organic framework derived polyhedral carbon frameworks, which could be beneficial for the exposure of more active sites, the optimization of electronic structure and the mass transfer of electrolyte/electron/ion.