ABSTRACT
Molecular phosphorescence in the second near-infrared window (NIR-II, 1000-1700 nm) holds promise for deep-tissue optical imaging with high contrast by overcoming background fluorescence interference. However, achieving bright and stable NIR-II molecular phosphorescence suitable for biological applications remains a formidable challenge. Herein, we report a new series of symmetric isocyanorhodium(I) complexes that could form oligomers and exhibit bright, long-lived (7-8 µs) phosphorescence in aqueous solution via metallophilic interaction. Ligand substituents with enhanced dispersion attraction and electron-donating properties were explored to extend excitation/emission wavelengths and enhanced stability. Further binding the oligomers with fetal bovine serum (FBS) resulted in NIR-II molecular phosphorescence with high quantum yields (up to 3.93%) and long-term stability in biological environments, enabling in vivo tracking of single-macrophage dynamics and high-contrast time-resolved imaging. These results pave the way for the development of highly-efficient NIR-II molecular phosphorescence for biomedical applications.
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We established myocardial injury models in vivo and in vitro to investigate the cardioprotective effect of gomisin D obtained from Schisandra chinensis. Gomisin D significantly inhibited isoproterenol-induced apoptosis and hypertrophy in H9C2 cells. Gomisin D decreased serum BNP, ANP, CK-MB, cTn-T levels and histopathological alterations, and inhibited myocardial hypertrophy in mice. In mechanisms research, gomisin D reversed ISO-induced accumulation of intracellular ROS and Ca2+. Gomisin D further improved mitochondrial energy metabolism disorders by regulating the TCA cycle. These results demonstrated that gomisin D had a significant effect on isoproterenol-induced myocardial injury by inhibiting oxidative stress, calcium overload and improving mitochondrial energy metabolism.
Subject(s)
Apoptosis , Isoproterenol , Oxidative Stress , Polycyclic Compounds , Schisandra , Animals , Isoproterenol/pharmacology , Mice , Molecular Structure , Schisandra/chemistry , Oxidative Stress/drug effects , Apoptosis/drug effects , Calcium/metabolism , Male , Reactive Oxygen Species/metabolism , Lignans/pharmacology , Lignans/chemistry , Cardiotonic Agents/pharmacology , Cell Line , Myocytes, Cardiac/drug effects , Cyclooctanes/pharmacology , Cyclooctanes/chemistryABSTRACT
The performance of the overhead squat may affect the golf swing mechanics associated with golf-related low back pain. This study investigates the difference in lumbar kinematics and joint loads during the golf downswing between golfers with different overhead squat abilities. Based on the performance of the overhead squat test, 21 golfers aged 18 to 30 years were divided into the highest-scoring group (HS, N = 10, 1.61 ± 0.05 cm, and 68.06 ± 13.67 kg) and lowest-scoring group (LS, N = 11, 1.68 ± 0.10 cm, and 75.00 ± 14.37 kg). For data collection, a motion analysis system, two force plates, and TrackMan were used. OpenSim 4.3 software was used to simulate the joint loads for each lumbar joint. An independent t-test was used for statistical analysis. Compared to golfers demonstrating limitations in the overhead squat test, golfers with better performance in the overhead squat test demonstrated significantly greater angular extension displacement on the sagittal plane, smaller lumbar extension angular velocity, and smaller L4-S1 joint shear force. Consequently, the overhead squat test is a useful index to reflect lumbar kinematics and joint loading patterns during the downswing and provides a good training guide reference for reducing the risk of a golf-related lower back injury.
Subject(s)
Golf , Biomechanical Phenomena , Lumbar Vertebrae , Posture , Mechanical Phenomena , MovementABSTRACT
OBJECTIVE: To investigate the safety and efficacy of novel CD19-KIRS2/Dap12-BB chimeric antigen receptor T cells (CAR-T cells) in the treatment of relapsed/refractory B-cell malignancy (R/R BCM). METHODS: Three patients with R/R BCM treated with novel CD19-KIRS2/Dap12-BB CAR-T cells from June 2020 to November 2020 were enrolled, including 1 case of B-cell acute lymphoblastic leukaemia (B-ALL) and 2 cases of non-Hodgkin's lymphoma (NHL), and the efficacy and adverse reactions were observed. RESULTS: After CAR-T cells infusion, patient with B-ALL achieved complete remission (CR) and minimal residual disease (MRD) turned negative, and 2 patients with NHL achieved partial remission (PR). Grade 2 cytokine release syndrome (CRS) occurred in B-ALL patient, grade 1 CRS occurred in 2 NHL patients, and grade II to IV hematologic adverse reactions occurred in 3 patients, all of which were controllable and reversible. The progression-free survival (PFS) of the 3 patients was 143, 199, and 91 days, and overall survival (OS) was 282, 430, and 338 days, respectively. CONCLUSION: The novel CD19-KIRS2/Dap12-BB CAR-T cells in treatment of 3 patients with R/R BCM have significant short-term efficacy and controllable adverse reactions, but the long-term efficacy needs to be further improved.
Subject(s)
Burkitt Lymphoma , Receptors, Chimeric Antigen , Humans , Immunotherapy, Adoptive , Antigens, CD19 , Neoplasm, Residual , Adaptor Proteins, Signal TransducingABSTRACT
Imaging-guided chemodynamic therapy is widely considered a promising modality for personalized and precision cancer treatment. Combining both imaging and chemodynamic functions in one system conventionally relies on the hybrid materials approach. However, the heterogeneous, ill-defined, and dissociative/disintegrative nature of the composites tends to complicate their action proceedings in biological environments and thus makes the treatment imprecise and ineffective. Herein, a strategy to employ two kinds of inorganic units with different functionsâreactive oxygen species generation and characteristic emissionâhas achieved two single-crystalline metal-organic frameworks (MOFs), demonstrating the competency of reticular chemistry in creating multifunctional materials with atomic precision. The multinary MOFs could not only catalyze the transformation from H2O2 to hydroxyl radicals by utilizing the redox-active Cu-based units but also emit characteristic tissue-penetrating near-infrared luminescence brought by the Yb4 clusters in the scaffolds. Dual functions of MOF nanoparticles are further evidenced by pronounced cell imaging signals, elevated intracellular reactive oxygen species levels, significant cell apoptosis, and reduced cell viabilities when they are taken up by the HeLa cells. In vivo NIR imaging is demonstrated after the MOF nanoparticles are further functionalized. The independent yet interconnected modules in the intact MOFs could operate concurrently at the same cellular site, achieving a high spatiotemporal consistency. Overall, our work suggests a new method to effectively accommodate both imaging and therapy functions in one well-defined material for precise treatment.
Subject(s)
Metal-Organic Frameworks , Nanoparticles , Neoplasms , Humans , Metal-Organic Frameworks/pharmacology , Metal-Organic Frameworks/chemistry , HeLa Cells , Reactive Oxygen Species , Hydrogen Peroxide , Phototherapy , Nanoparticles/chemistry , Neoplasms/diagnostic imaging , Neoplasms/drug therapy , Cell Line, TumorABSTRACT
High-resolution in vivo optical multiplexing in second near-infrared window (NIR-II, 1000-1700â nm) is vital to biomedical research. Presently, limited by bio-tissue scattering, only luminescent probes located at NIR-IIb (1500-1700â nm) window can provide high-resolution in vivo multiplexed imaging. However, the number of available luminescent probes in this narrow NIR-IIb region is limited, which hampers the available multiplexed channels of in vivo imaging. To overcome the above challenges, through theoretical simulation we expanded the conventional NIR-IIb window to NIR-II long-wavelength (NIR-II-L, 1500-1900â nm) window on the basis of photon-scattering and water-absorption. We developed a series of novel lanthanide luminescent nanoprobes with emission wavelengths from 1852â nm to 2842â nm. NIR-II-L nanoprobes enabled high-resolution in vivo dynamic multiplexed imaging on blood vessels and intestines, and provided multi-channels imaging on lymph tubes, tumors and intestines. The proposed NIR-II-L probes without mutual interference are powerful tools for high-contrast in vivo multiplexed detection, which holds promise for revealing physiological process in living body.
Subject(s)
Lanthanoid Series Elements , Nanoparticles , Neoplasms , Humans , Lanthanoid Series Elements/chemistry , Optical Imaging/methods , Spectroscopy, Near-Infrared/methods , Nanoparticles/chemistryABSTRACT
OBJECTIVE: To investigate the effect of hemoglobin (Hb) on the efficacy of chimeric antigen receptor T cell therapy (CAR-T) in patients with multiple myeloma (MM). METHODS: From June 2017 to December 2020, 76 MM patients who received CAR-T therapy in the Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, with complete clinical data and evaluable efficacy, were selected as the research objects. According to the receiver operating characteristic (ROC) curve, the best cut-off value was obtained. The patients were divided into groups on the basis of Hb 105.5 g/L as the cut-off value. The age, sex, serum calcium, ß2-microglobulin, serum creatinine, lactate dehydrogenase (LDH), and the influencing factors of CAR-T treatment efficacy in MM patients were analyzed. RESULTS: Hb was an influencing factor of efficacy. Univariate analysis showed that Hb, LDH, and albumin affected the efficacy of CAR-T therapy. Multivariate analysis showed that Hb ( OR=1.039, 95% CI: 1.002-1.078) and LDH ( OR=1.014, 95% CI: 1.000-1.027) were the influencing factors for the efficacy of CAR-T therapy. CONCLUSION: The efficacy of CAR-T therapy in MM patients with low Hb is poor, and Hb is a factor affecting the efficacy of CAR-T therapy.
Subject(s)
Hematologic Diseases , Multiple Myeloma , Receptors, Chimeric Antigen , Humans , Multiple Myeloma/drug therapy , Immunotherapy, Adoptive , Treatment OutcomeABSTRACT
Objective In recent years, many studies have reported that air pollution is a risk factor for type 2 diabetes mellitus (T2DM). The aim of this systematic review and meta-analysis is to summarize the evidence about the association between exposure to air pollution and T2DM in developing countries. Methods The databases, including PubMed, EMBASE and Web of Science, were systematically searched for studies published up to 31 March 2022. Studies about the association between air pollution and T2DM prevalence or incidence in developing countries were included. The odds ratio (OR) was used as effect estimate. We synthesized the included studies in the meta-analysis. Results We included 8 cross-sectional studies and 8 cohort studies, all conducted in developing countries. Meta-analysis of 8 studies on PM2.5 (particulate matter ≤ 2.5 µm in diameter) showed that T2DM prevalence was significantly associated with PM2.5 exposure (OR=1.12; 95% CI: 1.07, 1.17; P<0.001). The association between air pollutants and T2DM incidence was not estimated due to the limited relevant studies. Conclusions The exposure to PM2.5 would be positively associated with an increased prevalence of T2DM in developing countries. Some effective measures should be taken to reduce air pollutant exposure in people who are vulnerable to diabetes.
Subject(s)
Air Pollutants , Air Pollution , Diabetes Mellitus, Type 2 , Humans , Cross-Sectional Studies , Developing Countries , Environmental Exposure/analysis , Air Pollution/analysis , Particulate Matter , Air Pollutants/analysisABSTRACT
The oriental fruit fly Bactrocera dorsalis (Hendel) is a destructive polyphagous species that targets many economically important fruits and vegetables. The primary control of B. dorsalis relies mainly on the use of synthetic chemicals, and excessive use of these chemicals has adverse effects on both the environment and human health. Environmentally friendly management of pests involving plant essential oils is useful for controlling the populations of pests responsible for decreasing the yields and quality of crops. In the present study, we demonstrate that clove bud essential oil (CBEO) is strongly attractive to sexually mature males. Mature males responded to the CBEO differently throughout the day; the strongest response was elicited during the day and decreased at dusk. Virgin and mated mature males did not respond differently to CBEO. No obvious response behaviour to the CBEO was observed in two species of beneficial natural predator ladybirds. In addition, a cytotoxicity assessment demonstrated that CBEO is nontoxic to normal human and mouse cells. Based on our laboratory experiments, CBEO may serve as a promising, sustainable, and environmentally friendly attractant for B. dorsalis males; however, field experiments are needed to confirm this hypothesis.
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Panax notoginseng is a unique traditional medicinal plant in China, which has the effects of improving myocardial ischemia, protecting liver and preventing cardiovascular diseases (Jiang, 2020). In July 2021, gray-brown round spots were found on the leaves of P. notoginseng in the plantations of Lincang City (23º43´10ËN, 100º7´32ËE). By September, the symptoms were observed on more P. notoginseng plants, with incidence reaching 31%. Initial symptoms on leaves were small, brown spots that expanded, with black granular bulges on the lesions, often surrounded with yellow halo. As the disease progressed, multiple lesions merged, leaves became yellow, and abscission occurred. To isolate the causal pathogen, twelve symptomatic leaves were randomly obtained from twelve P. notoginseng plants. Small pieces of infected leaf tissues (about 5 mm2) were disinfected with 75% ethanol for 30 s, soaked in 2% sodium hypochlorite for 3 min, and then rinsed 3 times with sterile water and blotted dry. Sample tissues were plated on potato dextrose agar (PDA) plates incubated at 25â for 5 days with 12 h light/dark photoperiod. Hyphal-tips from the growing edge of colonies were transferred to fresh PDA to obtain pure cultures. Eight isolates were obtained with similar colony morphology, gray (top view) or black (back view) coloration, with a villous surface, and slow-growing on PDA. Conidia were hyaline, slender and obtuse to subobtuse at both ends, 10.3 to 52.62 (av. 25.2) µm × 1.4 to 4.0 (av. 2.4) µm (n=200) in size. Characteristics of the colonies and conidia were consistent with Caryophylloseptoria pseudolychnidis as described by Quaedvlieg et al. (2013) and Verkley et al. (2013). Genomic DNA of three representative isolates (LINC-4 to LINC-6) was extracted, and the rDNA-ITS region, ACT, and LSU gene regions were amplified and sequenced using the primer pairs ITS4/ITS5, 512F/783R, and LSU1Fd/LR5, respectively. Sequences have been deposited in GenBank (OK614104-OK614106 for ITS, OK614109-OK614111 for LSU, OK628350-OK628352 for ACT). BLAST search showed that all sequences were 98% to 100% homology with the corresponding sequences of C. pseudolychnidis. ITS sequences of the three isolates (LINC-4 to LINC-6) showed 99.21% identity (500/504 bp) to C. pseudolychnidis strain CBS 128630 (GenBank accession no. NR156266). LSU sequences of the three isolates showed 99.76% identity (823/825 bp) to C. pseudolychnidis strain CBS 128630 (MH876481). For ACT sequences, LINC-4 and LINC-5 showed 98.53% identity (201/204 bp) to C. pseudolychnidis strain 128614 (KF253599); LINC-6 showed 99.02% identity (202/204 bp) to C. pseudolychnidis strain 128614 (KF253599). Further, the neighbor-joining and maximum-likelihood method were used for multilocus phylogenetic analysis of the obtained sequences using MEGA-X (Kumar et al. 2018). The three isolates were clustered in the same clade with two C. pesudolychidis from database. Three isolates (LINC-4 to LINC-6) were tested for pathogenicity to confirm Koch's postulates. Annual potted P. notoginseng was inoculated with spore suspension (105 spores.mL-1). Each isolate was inoculated onto two leaves each of five P. notoginseng plants. The controls were similarly mock-inoculated with sterile water. To maintain high humidity (>90% RH), all plants were placed in transparent plastic boxes in a greenhouse at 25â with a 12 h light/dark photoperiod. Fifteen days post-inoculation, inoculated leaves showed similar symptoms to those observed in the field, and control plants remained healthy. The pathogen were reisolated from symptomatic leaf spots, and the colony characteristics were the same as those of the original isolates. Morphological characteristics, molecular data, and Koch's postulates tests confirmed C. pseudolychnidis as the cause of P. notoginseng leaf spot disease. To our knowledge, this is the first report of C. pseudolychnidis causing leaf spot on P. notoginseng in Yunnan, China. The spread of this disease might pose a serious threat to the production of P. notoginseng. The occurrence and spread of this pathogen should be further studied in order to formulate reasonable control measures.
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A hypoxic microenvironment is a common feature of skin wounds. Our previous study demonstrated that three-dimensional coculture of umbilical cord-derived mesenchymal stem cells (ucMSCs) and endothelial cells facilitates cell communication and host integration in skin tissue engineering. Here, we aimed to identify the mechanism by which ucMSCs affect endothelial cells under hypoxic conditions after skin injury. We demonstrate that hypoxia enhances the exosome-mediated paracrine function of ucMSCs, which increases endothelial cell proliferation and migration. In a mouse full-thickness skin injury model, ucMSC-derived exosomes can be taken up by endothelial cells and accelerate wound healing. Hypoxic exosomes lead to a better outcome than normoxic exosomes by promoting proliferation and inhibiting apoptosis. Mechanistically, microRNA-125b (miR-125b) transcription is induced by hypoxia in ucMSCs. After being packaged into hypoxic exosomes and transported to endothelial cells, miR-125b targets and suppresses the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1) and alleviates hypoxia-induced cell apoptosis. Inhibition of miR-125b-TP53INP1 interaction attenuates the protective effect of hypoxic exosomes. Moreover, artificial agomiR-125b can accelerate wound healing in vivo. Our findings reveal communication between ucMSCs and endothelial cells via exosomal miR-125b/TP53INP1 signaling in the hypoxic microenvironment and present hypoxic exosomes as a promising therapeutic strategy to enhance cutaneous repair.
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Luminescent materials with engineered optical properties have been developed for multiplexed labeling detection, where encoding capacity plays a pivotal role in the efficiency. However, multi-dimensional optical identities are usually not independent which essentially hinder the practical encoding numbers to access theoretical capacity. In this work, we carefully studied the sensitizer gradient doping structure in near-infrared (NIR) excitable upconversion nanoparticles (UCNPs) and managed to achieve independent emission intensity and lifetime tuning. With the orthogonally tunability, it breaks the constraint of intensity (k) and lifetime (n) correlation and expands the practical encoding number to theoretical value as (k+1)n -1 in binary encoding. This method can also be combined with previous lifetime engineering as well to realize high level multiplexing.
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A protein/lanthanide complex (BSA/Tb3+)-based sensor array in two different pH buffers has been designed for high-throughput recognition and time-resolved fluorescence (TRF) detection of metal ions in biofluids. BSA, which acted as an antenna ligand, can sensitize the fluorescence of Tb3+ (i.e., antenna effect), while the presence of metal ions would lead to the corresponding conformational change of BSA for altering the antenna effect accompanied by a substantial TRF performance of Tb3+. This principle has also been fully proved by both experimental characterizations and coarse-grained molecular dynamics (CG-MD) studies. By using Tris-HCl buffer with different pHs (at 7.4 and 8.5), 17 metal ions have been well-distinguished by using our proposed BSA/Tb3+ sensor array. Moreover, the sensor array has the potential to discriminate different concentrations of the same metal ions and a mixture of metal ions. Remarkably, the detection of metal ions in biofluids can be realized by utilizing the presented sensor array, verifying its practical applications. The platform avoids the synthesis of multiplex sensing receptors, providing a new method for the construction of convenient and feasible lanthanide complex-based TRF sensing arrays.
Subject(s)
Body Fluids/chemistry , High-Throughput Screening Assays , Metals, Heavy/analysis , Serum Albumin, Bovine/chemistry , Animals , Cattle , Fluorescence , Hydrogen-Ion Concentration , Molecular Dynamics Simulation , Spectrometry, Fluorescence , Time FactorsABSTRACT
A method is described for the determination of ascorbic acid (AA) in complex biological fluids. It based on maganese(II)-doped zinc/germanium oxide nanoparticles (Mn@ZnGe NPs) with appealing time-resolved phosphorescence (TRP). TRP can provide a background-free reporter signal in analytical methods. The absorption of AA overlaps the excitation band of Mn@ZnGe NPs at 254 nm. This reduces the intensity of fluorescence via an inner filter effect (IFE) with increasing concentration of AA. Typical experimental conditions include an emission peak at 536 nm, a delay time of 50 µs and a counting time of 2 ms. This method can detect AA in a range of 5-500 µM with a 0.13 µM limit of detection. If AA is oxidized by the enzyme AA oxidase (AAOx), dehydroascorbic acid will be formed which doesn't absorb at 254 nm. Hence, the IFE cannot occur and fluorescence is not reduced. The strategy can be used to quantify AAOx in the activity range of 1-4 U·mL-1. By using a handheld UV lamp and a smart phone with a color-scanning feature, the feasibility for visual detection and real-time/onsite quantitative scanometric monitoring of AA and AAOx is demonstrated. Graphical abstract Schematic presentation of a fluorometric method for determination of ascorbic acid (AA) and ascorbic oxidase and a scanometric visual assay. It based on the use of maganese(II)-doped zinc/germanium oxide nanoparticles (Mn@ZnGe NPs) with appealing time-resolved phosphorescence (TRP) and the inner-filter effect (IFE) between AA and Mn@ZnGe NPs.
Subject(s)
Ascorbate Oxidase/analysis , Ascorbic Acid/analysis , Fluorescent Dyes/chemistry , Metal Nanoparticles/chemistry , Animals , Ascorbic Acid/blood , Ascorbic Acid/urine , Enzyme Assays/instrumentation , Enzyme Assays/methods , Germanium/chemistry , Limit of Detection , Male , Manganese/chemistry , Rats , Smartphone , Spectrometry, Fluorescence/instrumentation , Spectrometry, Fluorescence/methods , Zinc/chemistryABSTRACT
The abundant functional groups on guanosine monophosphate (GMP) make it possible to interact with various metal ions. The subtle difference in the structure of GMP and deoxy-guanosine monophosphate (dGMP) coupled with Tb3+ can be readily exploited to form two coordination polymers, which have been unveiled as two time-resolved fluorescence (TRF) sensing reporters (Tb-GMP and Tb-dGMP) in our study. Based on this finding, herein, we have proposed a novel TRF orthogonal sensing array (Tb-GMP/dGMP) for pattern-recognition-based sensing of various metal ions. In addition, upon integration of some thiol-affinity metal ions, Tb-GMP/dGMP can be further extended to construct two metal ion-involved pattern-recognition-based sensor arrays (Tb-GMP/dGMP-Cu, Tb-GMP/dGMP-Ag) for the TRF sensing different levels of disease-relevant biothiols in biofluids, illustrating the powerful and multifunctional capabilities of the Tb-GMP/dGMP system and would inspire simpler and more widespread designs of chemical nose/tongue-based applications.
Subject(s)
Biosensing Techniques , Ions/isolation & purification , Metals/isolation & purification , Pattern Recognition, Automated/methods , Fluorescence , Ions/chemistry , Metals/chemistry , Nucleotides/chemistry , Polymers/chemistryABSTRACT
Recent years have witnessed thriving progress of flexible and portable electronics, with very high demand for cost-effective and tailor-made multifunctional devices. Here, we report on an ingenious origami hierarchical sensor array (OHSA) written with a conductive ink. Thanks to origami as a controllable hierarchical framework for loading ink material, we have demonstrated that OHSA possesses unique time-space-resolved, high-discriminative pattern recognition (TSR-HDPR) features, qualifying it as a smart sensing device for simultaneous sensing and distinguishing of complex physical and chemical stimuli, including temperature, relative humidity, light and volatile organic compounds (VOCs). Of special importance, OSHA has shown very high sensitivity in differentiating between structural isomers and chiral enantiomers of VOCs - opening a door for wide variety of unique opportunities in several length scales.
ABSTRACT
In this work, we present a novel facile strategy for green synthesis of polyethyleneimine (PEI)-capped carbon dots (PEI-CDs), in which citric acid and PEI were chosen as reactants and highly fluorescent PEI-CDs could be readily obtained via a simple one-pot refluxing under 120 °C within 2 H. Fluorescence studies indicate that the as-prepared PEI-CDs exhibit strong fluorescence emission at 446 nm with excitation at 365 nm. Upon the sequential addition of Cu2+ and H2 S, PEI-CDs result in an interesting "ON-OFF-ON" three-state emission responses, promising a bifunctional sensory platform. Moreover, the Cu2+ /H2 S-facilated reversible fluorescence changes of PEI-CDs have demonstrated the design of an INHIBIT logic system based on Boolean logic.
Subject(s)
Carbon/chemistry , Copper/analysis , Fluorescent Dyes/chemistry , Hydrogen Sulfide/analysis , Logic , Polyethyleneimine/chemistry , Quantum Dots/chemistry , Biological Assay/methods , Optical Imaging , Spectrometry, FluorescenceABSTRACT
Tb3+-doped carbon dots (Tb3+@CDs) were prepared in a facile hydrothermal method by using ammonium citrate as carbon source and Tb3+ as dopant. A 15-bp GT-rich single-strand DNA (ssDNA) was introduced to sensitize Tb3+ via the antenna effect for generating two fluorescence signals (CDs and Tb3+), forming a conjugate of Tb3+@CDs/ssDNA. The ratiometric fluorescence of Tb3+@CDs/ssDNA could be reversibly regulated by Ag+ and Cys, in which the fluorescence peak at 546â¯nm of Tb3+ could be switched to "On" or "Off" as the signal indicator while the fluorescence peak at 444â¯nm of CDs remained constant as the build-in reference. The proposed Ag+/Cys-mediated reversible fluorescence changes in Tb3+@CDs/ssDNA was also proven for the design of a self-calibrating ratiometric fluorescence logic system. By integrated with the specific reaction between H2O2 and Cys, Tb3+@CDs/ssDNA was applied for ratiometric fluorescence detection of H2O2. More importantly, the sensing strategy could be further successfully extended to the monitoring of H2O2-produced oxidase-related reactions, such as GOx-biocatalyzed oxidation of glucose (the limit of detection: 0.06⯵M) and was well applied in rat serum compared to commercial kits. This work unveiled a novel ratiometric fluorescent design, which is cost-effective, simple to prepare and easy-to-use without chemical modification or fluorescence labeling.
Subject(s)
Biosensing Techniques/methods , Carbon/chemistry , DNA, Single-Stranded/chemistry , Nanoparticles/chemistry , Oxidoreductases/metabolism , Terbium/chemistry , Animals , Base Sequence , Biocatalysis , Blood Glucose/analysis , Calibration , Cysteine/chemistry , Cystine/chemistry , DNA, Single-Stranded/genetics , Hydrogen Peroxide/chemistry , Male , Models, Molecular , Molecular Conformation , RatsABSTRACT
Screening functional DNA that can fruitfully interact with metal ions is a long-standing hot topic in the fields of biotechnology, medicine, and DNA-based sensors. In this paper, we focus on the chemistry of europium(III) (Eu) coupled with single-stranded DNA (ssDNA), and we innovatively unveil that cytosine- and thymine-rich ssDNA oligomers (e.g., C16 and T16) can be effective antenna ligands to sensitize the luminescence of Eu. Luminescence lifetime spectroscopy, circular dichroic (CD) spectroscopy, and isothermal titration calorimetry (ITC) have been used to systematically characterize the interaction involved between Eu and ssDNA. In light of the resultant sequence-dependent performances, the long luminescence lifetime Eu/ssDNA-based label-free and versatile probes are further devised as a pattern distinction system for time-resolved luminescent (TRL) sensing applications. The interactions of metal ions and ssDNA can distinctively shift the antenna effect of ssDNA toward Eu as accessible pattern signals. As a result, as few as two Eu/ssDNA label-free TRL probes can discriminate 17 metal ions via principal component analysis (PCA). In addition, thiols can readily capture metal ions to switch the luminescence of Eu/ssDNA probes initially altered by metal ions. Hence, four Eu/ssDNA-metal ion ensembles are demonstrated to be a powerful label-free TRL sensor array for pattern differentiation of eight thiols and even chiral recognition of cysteine enantiomers with different concentrations. Moreover, the sensitive TRL detection of thiols in biofluids can be successfully realized by using our method, promising its potential practical usage. This is the first report of a ssDNA-sensitized Eu-based TRL platform for label-free yet multifunctional background-free sensing and would open a door for sprouting of more novel lanthanide ion/DNA-relevant strategies toward widespread applications.