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1.
Anal Chem ; 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32233376

RESUMO

Single-cell analysis facilitates perception into the most essential processes in life's mysteries. While it is highly challenging to quantify them at the single-cell level, where precise single-cell sampling is the pre-requisite. Herein, a real-time single-cell quantitative platform was established for high-throughput droplet-free single-cell sampling into time-resolved (TRA) ICP-MS and real-time quantification of intracellular target elements. The concentrated cells (2×106 cells mL-1) were spontaneously and orderly aligned in a spiral micro-channel with 104 periodic dimensional confined micro-pillars. The quantification is conducted simultaneously by internal standard inducing from another branch channel in the chip. The flow rate independent feature of single-cell focusing into an aligned stream within a wide range of fluidic velocity (100-800 µL min-1) facilitates high-throughput oil-free single-cell introduction into TRA-ICP-MS. The system was used for real-time exploration of intracellular antagonism of Cu2+ against Cd2+. Obvious antagonistic effect was observed for MCF-7 cell by culturing for 3, 6, 9, 12 h with 100 µg L-1 Cd2+ & 100 µg L-1 Cu2+, and a rivalry rate of 12.8% was achieved at 12 h. At identical experimental conditions, however, limited antagonistic effect was encountered for bEnd3 cell within the same incubation time period, with a rivalry rate of 4.81%. On the contrary, antagonistic effect was not observed for HepG2 cell by culturing for 6 h, while obvious antagonistic effect was found by further culturing to 12 h, with a rivalry rate of 10.43%. For all the three cell lines, significant heterogeneity was observed among individual cells.

2.
Nanoscale ; 12(12): 6852-6860, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32186547

RESUMO

Regulating the fluorescence of carbon dots (CDs) is important but highly challenging. Here, carbon dots with tunable dual emissions were facilely fabricated via modulating the polymerization and carbonization processes of o-phenylenediamine (OPD) with lysine (Lys) as the co-precursor and modulator, respectively. The self-polymerization/carbonization of the OPD molecules contributed to the blue/green emission of the OPD-derived CDs. The introduction of Lys in the CD fabrication process efficiently suppressed the carbonization of the OPD polymer chains and enhanced the self-polymerization of the OPD molecules. Meanwhile, the formed OPD-Lys co-polymer chains endowed the final CD product with a new green emission center. The dual-emissive CDs were distinctly sensitive to polarity fluctuations, providing a ratiometric fluorescence response towards solution polarity. Due to their specific distribution in the endoplasmic reticulum (ER), the as-prepared dual-emissive CDs successfully distinguished the polarity variations in ER under stress, which offers a new approach for the early diagnosis of cell injury.

3.
Anal Chim Acta ; 1108: 54-60, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32222244

RESUMO

It is still a high challenge to develop a simple, sensitive and portable approach for bioassay in strong scattering medium. Herein, a photoacoustic (PA) device is developed for the detection of alkaline phosphatase (ALP) in serum with silver nanoparticles (AgNPs) as signal probe, without any requirements for expensive equipment, professional operation and pre-processing of real samples. ALP as an important disease marker could catalyze the breakdown of sodium L-ascorbyl-2-phosphate (AAP) into ascorbic acid (AA), thereby reducing Ag+ to AgNPs. AgNPs could generate strong PA signal under the irradiation of modulated 638-nm laser due to their localized plasmon resonance, and detected by the self-made portable PA device. Under the optimized experimental conditions, the present PA device exhibits excellent photostability and reproducibility with the relative standard deviation (RSD) of 2.2% at the concentration of 25 U L-1 ALP. Linear calibration graph is obtained within 5-70 U L-1 for ALP, along with a detection limit of 1.1 U L-1. This portable PA device is applied to detect ALP in serum samples, providing satisfactory spiking recoveries and competitive analytical performances with the current techniques. The PA-based analytical strategy obviously opens up a new avenue to the detection of disease-correlated biomarker in practice.

4.
Sci Rep ; 10(1): 4526, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32161294

RESUMO

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide. While both genetic and environmental factors have been linked to the incidence and mortality associated with CRC, an ethnic aspect of its etiology has also emerged. Since previous large-scale cancer genomics studies are mostly based on samples of European ancestry, the patterns of clinical events and associated mechanisms in other minority ethnic patients suffering from CRC are largely unexplored. We collected 104 paired and adjacent normal tissue and CRC tumor samples from Taiwanese patients and employed an integrated approach - paired expression profiles of mRNAs and microRNAs (miRNAs) combined with transcriptome-wide network analyses - to catalog the molecular signatures of this regional cohort. On the basis of this dataset, which is the largest ever reported for this type of systems analysis, we made the following key discoveries: (1) In comparison to the The Cancer Genome Atlas (TCGA) data, the Taiwanese CRC tumors show similar perturbations in expressed genes but a distinct enrichment in metastasis-associated pathways. (2) Recurrent as well as novel CRC-associated gene fusions were identified based on the sequencing data. (3) Cancer subtype classification using existing tools reveals a comparable distribution of tumor subtypes between Taiwanese cohort and TCGA datasets; however, this similarity in molecular attributes did not translate into the predicted subtype-related clinical outcomes (i.e., death event). (4) To further elucidate the molecular basis of CRC prognosis, we developed a new stratification strategy based on miRNA-mRNA-associated subtyping (MMAS) and consequently showed that repressed WNT signaling activity is associated with poor prognosis in Taiwanese CRC. In summary, our findings of distinct, hitherto unreported biosignatures underscore the heterogeneity of CRC tumorigenesis, support our hypothesis of an ethnic basis of disease, and provide prospects for translational medicine.

5.
Anal Chem ; 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32141734

RESUMO

The enzyme-linked immunosorbent assay (ELISA) is widely used in clinical diagnostics. However, conventional ELISA is labor-intensive and lengthy. Herein, the sensitive detection of biomarkers with only one-step incubation of 20 min is demonstrated, based on antibody-fused, boronic-acid-decorated carbon nitride nanosheets. The decoration of carbon nitride nanosheets with boronic acid facilitates antibody binding at physiological conditions along with a concomitant fluorescence enhancement. The presence of target antigen results in a decrement of the fluorescence and ensures one-step immunofluorescent detection. The immune recognition of the antibody/target antigen in combination with glucose blocking ensures a highly selective assay of the biomarkers. The protocol is validated by the assay of nonglycoprotein, glycoprotein, and small-molecular-toxin targets. The multiplex target detection capability is demonstrated by the simultaneous assay of the triple cardiac biomarker cTnI, Mb, and CK-MB in human serum.

6.
Crit Rev Anal Chem ; : 1-20, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32182101

RESUMO

In an effort to achieve high sensitivity analysis methods for ultra-trace levels of heavy metals, numerous new nanomaterials are explored for the application in preconcentration processes and sensing systems. Nanomaterial-based methods have proven to be effective for selective analysis and speciation of heavy metals in combination with spectrometric techniques. This review outlined the different types of nanomaterials applied in the field of heavy metal analysis, and concentrated on the latest developments in various new materials. In particular, the functionalization of traditional materials and the exploitation of bio-functional materials could increase the specificity to target metals. The hybridization of multiple materials could improve material properties, to build novel sensor system or achieve detection-removal integration. Finally, we discussed the future perspectives of nanomaterials in the heavy metal preconcentration and sensor design, as well as their respective advantages and challenges. Despite impressive progress and widespread attention, the development of new nanomaterials and nanotechnology is still hampered by numerous challenges, particularly in the specificity to the target and the anti-interference performance in complex matrices.

7.
Chem Commun (Camb) ; 56(20): 3050-3053, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32048645

RESUMO

We constructed a carbon-based polymer dot (CPD) sensor to detect breast cancer based on the differences of peripheral blood cells, providing a new minimally invasive method for cancer diagnosis. This simple and extensible system exhibits clinically relevant accuracy in terms of cancer identification, making it an attractive strategy for diagnosis and prognosis.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Carbono/química , Corantes Fluorescentes/química , Leucócitos Mononucleares/patologia , Polímeros/química , Pontos Quânticos/química , Feminino , Fluorescência , Humanos , Imunidade Celular/imunologia , Leucócitos Mononucleares/imunologia , Imagem Óptica
8.
Anal Chim Acta ; 1104: 78-86, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32106960

RESUMO

Novel flower-type and three-dimensional porous nanoparticles are prepared for the isolation of low density lipoprotein (LDL). The amino-terminated dendritic mesoporous silica nanoparticles (A-DMSNs) show highly accessible central-radial pore (0.655 cm3 g-1) and surface area (362.263 m2 g-1), which play an important role in the superior adsorption capacity of 816.7 µg mg-1. The A-DMSNs is anchored with chondroitin sulfate (CS), shortly termed as ADC, for ensuring the selectivity of the adsorption. The adsorbed LDL is thereafter readily recovered at pH 9.0 by using 4 mmol L-1 Britton-Robinson buffer as stripping reagent, providing a recovery of 79.1%. ADC nanoparticles are further applied as sorbent for the selective isolation of LDL from simulated serum of hypercholesterolemia patient. High-purity LDL is achieved as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) assays.

9.
ACS Appl Mater Interfaces ; 12(8): 9000-9007, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32013385

RESUMO

A novel hybrid drug nanocarrier is developed with CuCo2S4 nanoparticles as the core to be encapsulated by poly(ionic liquid) (PIL), that is, poly(tetrabutylphosphonium styrenesulfonate) (P[P4,4,4,4][SS]), as the shell. Doxorubicin (DOX) is loaded onto the PIL shell via electrostatic attraction involving amine in DOX and styrenesulfonate in PIL. pH- and thermal-responsive characteristics of P[P4,4,4,4][SS] endow the multifunctional hybrid nanocarrier system DOX-CuCo2S4@PIL with sensitive dual-stimuli-triggered drug release behaviors. The CuCo2S4 core converts near-infrared (NIR) irradiation into thermal energy to trigger the shrinkage of the PIL shell, which subsequently promotes drug release, and the pH-responsive release of DOX involves pH-sensitive electrostatic interaction of the PIL shell with DOX. A favorable controlled release of 90.5% is achieved under pH/thermo dual stimuli. In vitro experiments with MCF-7 cells well demonstrated that the drug release is controlled by the acidic intracellular environment with NIR irradiation. The CuCo2S4 core also serves as a photoacoustic (PA) imaging contrast agent, as demonstrated by in vivo treatment of the MCF-7-carrying mice.

10.
Mikrochim Acta ; 187(3): 162, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32048050

RESUMO

Nitrogen-doped flower-like carbon superstructures (NPC-F) are prepared via carbonizing self-assembled polyimide nanosheets. SEM, TEM, XPS, and N2 sorption methods are adopted to characterize the flower-like structure. NPC-F exhibits adsorption selectivity for hemoglobin (Hb) because the specific pyridinic N groups of NPC-F could coordinate with the sixth vacancy of ferrous ion in hemoglobin. The adsorption behavior fits well with Langmuir model with a maximum adsorption capacity of 360.0 mg g-1 and the adsorbed Hb could be lightly stripped from the NPC-F nanospheres surface by 0.5 wt% CTAB solution. Circular dichroism spectra indicate no obvious conformation changing of Hb during purification process by NPC-F nanospheres. Five cycles of a continuous adsorption/desorption experiment demonstrate the reusability of NPC-F as adsorbent for Hb. The prepared NPC-F superstructures are then employed for the isolation of Hb from human whole blood sample, obtaining high-purity Hb as demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis assays. Graphical abstractNitrogen-doped flower-like carbon superstructure (NPC-F) is used to isolate target protein. NPC-F exhibits highly selective capture capacity towards hemoglobin because the specific pyridinic N groups of NPC-F could coordinate with the sixth vacant coordinating position of Fe2+ in hemoglobin.

11.
Mol Carcinog ; 59(3): 311-322, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31943339

RESUMO

Gastric cancer (GC) is one of the most common malignancies of the digestive system worldwide. Multiple long noncoding RNAs (lncRNAs) participate in the regulation of GC development and metastasis. In this study, we aimed to elucidate the expression and function of lncRNA IGFL2-AS1 in GC. We found that IGFL2-AS1 was highly expressed in GC tissues and cell lines. Knockdown of IGFL2-AS1 suppressed GC cell proliferation, migration, and invasion in vitro. Furthermore, we identified that IGFL2-AS1 exerted its function as a molecular sponge of miR-802. MiR-802 was demonstrated to be a tumor suppressor, and overexpression of miR-802 suppressed GC cell growth, migration, and invasion. Mechanistically, we revealed that the cAMP-regulated phosphoprotein 19 (ARPP19) was a direct target of miR-802 and could reverse the inhibitory function of miR-802. Moreover, our results confirmed that knockdown of IGFL2-AS1 inhibited GC tumor development in an in vivo GC tumor xenograft model. In summary, our data suggest that the IGFL2-AS1/miR-802/ARPP19 axis plays a critical role in the progression and metastasis of GC. Therapies targeting the IGFL2-AS1/miR-802/ARPP19 axis can potentially improve GC treatment.

12.
Talanta ; 210: 120620, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987167

RESUMO

Boronate affinity is widely used for the isolation of glycoproteins at alkaline conditions. For further proteomic studies, however, it is of highly importance to perform protein adsorption in neutral medium. For this purpose, we report a novel composite material, i.e., 4-carboxyphenylboronic acid (CPBA) functionalized nickel-substituted polyoxometalate [Ni6(en)3(Tris)(H2O)2(PW9O34)]•nH2O (Ni6PW9)-sodium alginate (SA) hybrid. The abundant oxygen atoms in the hybrid (shortly termed as CPBA-Ni6PW9/SA) significantly reduce the pKa value of CPBA moiety, which well facilitates the selective adsorption of glycoproteins at neutral environment (at pH 7.0). The moiety of sodium alginate (SA) in the hybrid further improves the isolation/enrichment capacity for glycoproteins through hydrophilic interaction. The adsorption efficiency of Immunoglobulin G (IgG, 1.0 mL, 100 µg mL-1) by 1.0 mg CPBA-Ni6PW9/SA hybrid reaches up to 91%, and 1.0 mL of Tris-HCl buffer (100 mmol L-1) provides an elution efficiency of 82%. The adsorption behavior of IgG fits Langmuir adsorption model, offering a maximum adsorption capacity of 495 mg g-1. The CPBA-Ni6PW9/SA hybrid is practically applied for the enrichment of glycoproteins from human serum. SDS-PAGE assay result indicates that approximately 92% serum albumin is eliminated and high-purity IgG is obtained. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis clearly demonstrated that after enriching with CPBA-Ni6PW9/SA, 81 glycoproteins are identified and 79.4% recognition selectivity is achieved.

13.
Anal Chem ; 92(5): 3769-3774, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-31931569

RESUMO

Alkaline phosphatase (ALP) plays critical roles in signal transmission and cell growth/apoptosis. Its abnormal level in serum/cell is tightly related to diseases, thus, serum and cellular ALP detection is of great significance for disease diagnosis. Herein, a novel approach for ALP assay based on a satellite-nanostructure is developed by conjugating lanthanide upconversion nanoparticles (UCNPs) with silver nanoclusters (AgNCs) through DNA bridging. UCNPs serve as the cores to conjugate with DNA fragments, followed by assembly of AgNCs as the satellites on UCNPs surface through the AgNCs-cytosine affinity, to produce the satellite-nanostructure of UCNPs@DNA-AgNCs. The presence of ALP converts phosphate groups into hydroxyl groups at DNA helix, weakening the coordination of DNA with UCNPs. As a result, the satellite AgNC labeling on DNA fragments strips off the UCNP surface. Silver is quantified by measuring isotope 107Ag with ICP-MS, which further derives the content of ALP by correlation to the number of AgNCs. A linear calibration range is obtained in 0.005-120 U/L with a detection limit of 1.8 mU/L. The distinct advantage of this strategy, on one hand, is the substrate-free feature that eliminates the intermediate process of substrate reaction, where the substrate activity decrease and its instability may significantly deteriorate the sensitivity. On the other hand, ALP triggers the production of a large number of AgNCs resulting in substantial amplification on ICP-MS signal to give a favorable sensitivity. This is the first attempt for ALP detection by inductively coupled plasma mass spectrometry.

14.
Chem Commun (Camb) ; 56(11): 1717-1720, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31942593

RESUMO

A novel sensor array based on a (+)AuNP/AuNC nanocomposite was constructed for the selective discrimination of 10 types of Gram-negative bacteria (including 3 types of antibiotic-resistant strains) at a low concentration level of OD600 = 0.015. By recognizing the triple optical patterns of Gram-negative bacteria with the assistance of LDA, the sensor array is able to group the bacteria with respect to their species to each other.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Bactérias Gram-Negativas/isolamento & purificação , Nanopartículas Metálicas/química , Análise por Conglomerados , Análise Discriminante , Ouro/química , Bactérias Gram-Negativas/classificação , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Nanocompostos/química , Espalhamento de Radiação , Espectrometria de Fluorescência , Urina/microbiologia , Vancomicina/química
15.
Chin Med J (Engl) ; 133(2): 212-220, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31929369

RESUMO

BACKGROUND: Recent evidence has shown that prophylactic antibiotic treatment in patients with acute pancreatitis is not associated with a significant decrease in mortality or morbidity. The use and efficacy of prophylactic antibiotic treatment in acute pancreatitis remain controversial. This meta-analysis was conducted to assess whether antibiotic prophylaxis is beneficial in patients with acute pancreatitis. METHODS: We searched randomized controlled trials (RCTs) of prophylactic use of antibiotics using Medline (PubMed), Embase, the Cochrane Library, and Web of Science. The data were analyzed using Review Manager 5.3 software. We performed pooled analyses for infected pancreatic necrosis, mortality, surgical intervention, and non-pancreatic infection. Odds ratios (ORs) from each trial were pooled using a random or fixed effects model, depending on the heterogeneity of the included studies. Sub-group analysis or sensitivity analysis was conducted to explore potential sources of heterogeneity, when necessary. RESULTS: Totally, 11 RCTs involving 747 participants were included, with an intervention group (prophylactic use of antibiotics, n = 376) and control group (n = 371). No significant differences were found regarding antibiotic prophylaxis with respect to incidence of infected pancreatic necrosis (OR, 0.74; 95% confidence interval [CI], 0.50-1.09; P = 0.13), surgical intervention (OR, 0.92; 95% CI, 0.62-1.38; P = 0.70), and morality (OR, 0.71; 95% CI, 0.44-1.15; P = 0.16). However, antibiotic prophylaxis was associated with a statistically significant reduction in the incidence of non-pancreatic infection (OR, 0.59; 95% CI, 0.42-0.84; P = 0.004). CONCLUSIONS: Prophylactic antibiotics can reduce the incidence of non-pancreatic infection in patients with AP.

16.
Talanta ; 209: 120527, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892079

RESUMO

Photoacoustic (PA) effect has been widely applied in many fields, e.g., physics, chemistry and biomedicine. Herein, a miniaturized PA device is developed by integrating laser source, photo chopper, PA cell, microphone, and laptop for point-of-care testing in bioassay. With glucose assay as model, a piece of paper strip preloading chitosan, starch-potassium iodide (KI) and glucose oxidase (GOD) as lab-on-paper is employed for loading sample prior to PA detection. In the presence of glucose, the product generated on the paper strip would give rise to a strong PA signal in the PA cell under the irradiation of frequency-modulated laser at 520 nm via laptop readout. With a sample volume of 20 µL, a detection limit of 0.03 mM is obtained for glucose assay, along with a linear range of 0.08-1 mM. The accuracy and practicability of the present PA device is well demonstrated by detecting glucose in whole blood. Differing from the conventional PA instrument, the present PA device is really small in bulk with competitive sensitivity and excellent stability, offering a promising tool for point-of-care testing in bioassay.

17.
J Mater Chem B ; 8(7): 1396-1404, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31971208

RESUMO

In this study, CuS@PDA nanoparticles were synthesized and used to create a novel tumor-targeting nanocomposite platform composed of copper sulfide@polydopamine-folic acid/doxorubicin (CuS@PDA-FA/DOX) for performing both photothermal and chemotherapeutic cancer treatment. The nanocomposite platform has ultrahigh loading levels (4.2 ± 0.2 mg mg-1) and a greater photothermal conversion efficiency (η = 42.7%) than CuS/PDA alone. The uptake of CuS@PDA-FA/DOX nanocomposites is much higher in MCF-7 cells than in A549 cells because MCF-7 cells have much higher folic acid receptors than A549. Under near infrared (NIR) irradiation, the CuS@PDA-FA/DOX system using a synergistic combination of photothermal therapy and chemotherapy yields a better therapeutic effect than either photothermal therapy or chemotherapy alone. The treatment is very effective with the cell viability is only 5.6 ± 1.4%.

18.
Adv Mater ; 32(9): e1907233, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31957100

RESUMO

Super-resolution microscopy, as a powerful tool of seeing abundant spatial details, typically can only distinguish a few distinct targets at a time due to the spectral crosstalk between fluorophores. Spaser (i.e., surface plasmon laser) nanoprobes, which confine lasing emission into nanoscale, offer an opportunity to eliminate such obstacle. Here, realized is narrow band stimulated emission depletion (STED) nanoscopy on spaser nanoparticles by collecting the coherent spasing signals. Demonstrated are the physics concept and feasibility of erasing spaser emission by using a depletion beam to suppress the population inversion, which lays the foundation of spaser-based STED super-resolution. Thanks to the small size (47 nm) and narrow spectral linewidth (3.8 nm) of the spaser nanoparticles, a 74 nm spatial resolution in STED imaging within an acquisition bandwidth of 10 nm is finally obtained. These spaser nanoparticles, if multiplexing with different wavelengths, in principle, allow for spectral-multiplexed imaging, sensing, cytometry, and light operation of a large number of targets all at once.

19.
Anal Chem ; 92(1): 1395-1401, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31830782

RESUMO

Longitudinal surface plasmon resonance (LSPR)-based optical signals possess unique advantages in biomolecular sensing and detection which can be attributed to their ultrahigh sensitivity and signal-to-noise ratio. However, the lack of effective strategies for morphological control of gold nanorods (GNRs) complicates the precise tuning of their LSPR property. Herein, a "peptide-encoded" strategy was first developed to precisely control the morphologies of GNRs via overgrowth of GNR seeds in the presence of thiol-containing peptides. Significantly, the "peptide-encoded" GNRs exhibit a tunable LSPR peak ranging from 685 to 877 nm by altering the amount of peptide. A few obvious colorimetric changes were accompanied from pink to purple and even to blue. Other parameters, e.g., pH, temperature, and Ag+ concentration, could also be utilized to regulate the morphologies of the "peptide-encoded" GNRs. The ultrasensitive detection of tumor-related protease activities based on LSPR peak shifts was further successfully performed without the need for labeling or instrumental aid, achieving a limit of detection of 60 fM. It is much lower than traditional absorption-based analysis (1 nM) and enzyme-linked immunosorbent assay (ELISA) method (1 pM), indicating the great potential of this peptide-encoded strategy in the application of ultrasensitive biomarker assay and clinical diagnosis.

20.
J Hazard Mater ; 382: 121056, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31470305

RESUMO

We report a new 7-nitrobenzo-2-oxa-1, 3-diazolyl (NBD)-based chemosensor containing a piperazine derivative, NBDP, for detection of mercury ions in almost 100% aqueous medium. The chemosensor shows sensing exclusively toward Hg2+ with a switch-on fluorescence response at 543 nm, which could be attributed to the blocking of PET (photo-induced electron transfer) process upon complexation with mercury ions. The molar ratio of Hg(Ⅱ) to NBDP in the complex is 1:1 based on the Job's plot and HRMS studies. Optimized configurations of NBDP and NBDP-Hg2+ complexes were simulated by means of DFT calculations. The reversible fluorescence response with low detection limit (19.2 nM) in the pH range of 6.0-7.5 renders NBDP a promising candidate for Hg2+ detection in neutral aqueous environments. For the practical application of the chemosensor, test strips were successfully fabricated for rapid detection of Hg2+ ions. Moreover, the utility of NBDP showing the mercury recognition in Human liver cancer cells (SMMC-7721) and zebrafish as well as in live tissues of Arabidopsis thaliana has been demonstrated as monitored by fluorescence imaging.

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