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1.
Front Cell Infect Microbiol ; 14: 1329235, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38638828

RESUMO

The metagenomic next-generation sequencing (mNGS) method is preferred for genotyping useful for the identification of organisms, illumination of metabolic pathways, and determination of microbiota. It can accurately obtain all the nucleic acid information in the test sample. Anthrax is one of the most important zoonotic diseases, infecting mainly herbivores and occasionally humans. The disease has four typical clinical forms, cutaneous, gastrointestinal, inhalation, and injection, all of which may result in sepsis or meningitis, with cutaneous being the most common form. Here, we report a case of cutaneous anthrax diagnosed by mNGS in a butcher. Histopathology of a skin biopsy revealed PAS-positive bacilli. Formalin-fixed paraffin-embedded (FFPE) tissue sample was confirmed the diagnosis of anthrax by mNGS. He was cured with intravenous penicillin. To our knowledge, this is the first case of cutaneous anthrax diagnosed by mNGS using FFPE tissue. mNGS is useful for identifying pathogens that are difficult to diagnose with conventional methods, and FFPE samples are simple to manage. Compared with traditional bacterial culture, which is difficult to cultivate and takes a long time, mNGS can quickly and accurately help us diagnose anthrax, so that anthrax can be controlled in a timely manner and prevent the outbreak of epidemic events.


Assuntos
Antraz , Dermatopatias Bacterianas , Masculino , Humanos , Antraz/diagnóstico , Inclusão em Parafina , Formaldeído/uso terapêutico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Sensibilidade e Especificidade
2.
Anal Methods ; 16(16): 2606-2613, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38618990

RESUMO

2,6-Pyridinedicarboxylic acid (DPA) is a significant biomarker of anthrax, which is a deadly infectious disease for human beings. However, the development of a convenient anthrax detection method is still a challenge. Herein, we report a novel europium metal-organic framework (Eu-MOF) with an enhanced peroxidase-like activity and fluorescence property for DPA detection. The Eu-MOF was one-step synthesized using Eu3+ ions and 2-methylimidazole. In the presence of DPA, the intrinsic fluorescence of Eu3+ ions is sensitized, the fluorescence intensity linearly increases with an increase in DPA concentration, and the fluorescence color changes from blue to purple. Simultaneously, the peroxide-like activity of the Eu-MOF is enhanced by DPA, which can promote the oxidation of TMB to oxTMB. The absorbance values increase linearly with DPA concentrations, and the colorimetric images change from colorless to blue. The dual-mode detection of DPA has good sensitivity with a colorimetric detection limit of 0.67 µM and a fluorescent detection limit of 16.67 nM. Moreover, a simple detection method for DPA was developed using a smartphone with the RGB analysis system. A portable kit with standard color cards was developed using paper test strips. The proposed methods have good practicability for DPA detection in real samples. In conclusion, the developed Eu-MOF biosensor offers a valuable and general platform for anthrax diagnosis.


Assuntos
Colorimetria , Európio , Estruturas Metalorgânicas , Ácidos Picolínicos , Európio/química , Estruturas Metalorgânicas/química , Colorimetria/métodos , Ácidos Picolínicos/análise , Ácidos Picolínicos/química , Limite de Detecção , Humanos , Fluorescência , Antraz/diagnóstico , Smartphone , Espectrometria de Fluorescência/métodos , Peroxidase/química , Peroxidase/metabolismo
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123964, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38286080

RESUMO

In this work, a stable ratiometric nanofluorescent probe for the detection of 2,6-dipicolinic acid (DPA), a Bacillus anthracis biomarker, was developed based on confinement-induced emission enhancement of cationic styrylpyridine salt derivative L in MCM-22 molecular sieve pores. The cationic L and the lanthanide Tb3+ were loaded into the pores of the molecular sieve by electrostatic interaction with the negatively charged AlO4 tetrahedron unit, and L exhibited enhanced red fluorescence emission as a stable fluorescence reference mark in the nanoprobe platform due to the restricted molecular torsion of L in the pores of MCM-22. At the same time, the characteristic green fluorescence emission of Tb3+ can be excited by energy transfer due to the "antenna effect" of DPA. The prepared Tb-L@MCM-22 nanoprobe showed specific selectivity and stable fluorescence ratiometric detection of DPA in tap water, lake water, bovine serum and actual bacterial spores. Benefiting from the confinement-induced fluorescence enhancement effect of L in the MCM-22 molecular sieve pores, the obtained Tb-L@MCM-22 can provide a stable reference signal for the fluorescence ratiometric detection of DPA with a limit of detection (LOD) of 78.6 nM and 1.310 × 104 spores per mL. More importantly, combining of the Tb-L@MCM-22 based DPA detection test strips with a smartphone app demonstrated a stable, convenient and rapid method for detecting of anthrax biomarkers.


Assuntos
Antraz , Bacillus anthracis , Humanos , Fluorescência , Piridinas , Ácidos Picolínicos , Antraz/diagnóstico , Cloreto de Sódio , Biomarcadores , Água , Corantes Fluorescentes
4.
Anal Chim Acta ; 1288: 342181, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38220309

RESUMO

2,6-pyridinedicarboxylic acid (DPA) is an excellent biomarker of Bacillus anthracis (B. anthracis). The sensitive detection of DPA, especially through visual point-of-care testing, was significant for accurate and rapid diagnosis of anthrax to timely prevent anthrax disease or biological terrorist attack. Herein, a ratiometric fluorescent (R-FL) and electrochemiluminescent (ECL) dual-mode detection platform with a lanthanide ion-based metal-organic framework (Ln-MOF, i.e., M/Y-X: M = Eu, Y = Tb, and X = 4,4',4″-s-triazine-1,3,5-triyltri-m-aminobenzoic acid) was developed. Eu/Tb-TATAB nanoparticles were constructed to identify DPA. The R-FL detection platform quantitatively detected DPA by monitoring the I545/I617 ratio of the characteristic fluorescence peak intensities of Tb3+ ions and Eu3+ ions. The ECL sensing platform successfully quantified DPA by exploiting the burst effect of DPA on the ECL signal. The above methods had highly sensitive and rapid detection of DPA in water and serum samples. The results showed that this dual-mode detection platform may be projected to be a powerful instrument for preventing related biological warfare and bio-terrorism.


Assuntos
Antraz , Ácidos Picolínicos , Humanos , Antraz/diagnóstico , Corantes Fluorescentes , Biomarcadores , Íons
5.
Medicine (Baltimore) ; 103(3): e36921, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38241573

RESUMO

RATIONALE: Anthrax is a severe zoonotic infectious disease caused by Bacillus anthracis. Most reported cases were traditionally diagnosed through culture and microscopy. We reported here the second case of cutaneous anthrax diagnosed by metagenomic next-generation sequencing (mNGS). PATIENT CONCERNS: A 63-year-old man had a history of contact with an unwell sheep, developing local redness and swelling on wrist. The dorsal side of the left hand and forearm, with tension blisters on the back of the left. DIAGNOSIS: B anthracis was detected from culturing and mNGS of tension blisters. INTERVENTIONS: On the second day of admission, the patient was administered 3.2 million units of penicillin every 6 hours, and isolated and closely observed. OUTCOMES: The patient improves and is discharged. LESSONS: Traditional bacterial cultures are time-consuming, while mNGS offers the advantage of accurate, quick, high-throughput, unbiased sequencing of all genetic material in a sample, which is a good technical tool for assisting in the diagnosis of rare pathogen infections.


Assuntos
Antraz , Bacillus anthracis , Dermatopatias Bacterianas , Masculino , Humanos , Animais , Ovinos , Pessoa de Meia-Idade , Antraz/diagnóstico , Antraz/microbiologia , Vesícula , Dermatopatias Bacterianas/diagnóstico , Bacillus anthracis/genética , Sequenciamento de Nucleotídeos em Larga Escala
6.
Int J Infect Dis ; 140: 104-109, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38195038

RESUMO

OBJECTIVES: Bacillus anthracis infection is a worldwide zoonosis that affects the most vulnerable population and has a high mortality rate without treatment, especially in non-cutaneous presentations. Cutaneous scarification is still common in some regions of the world for the treatment of certain diseases as part of traditional medicine. We describe a series of cutaneus anthrax from a rural setting in Angola where cutaneus scarification is common. CASE PRESENTATION: This is a retrospective observational study describing a series of cutaneous anthrax cases from Cubal (Angola), many of whom were treated with skin scarification before admission. A total of 26 cases were diagnosed from January 2010 to December 2018. None of the cases were confirmed and eight (30.8%) were probable cases according to the Centers for the Disease Control and Prevention anthrax case definition. The median age was 11 (4.7-30.5) years, 17 (65.4%) had lesions on the head, face, or neck and 15 (57.7%) were treated with cutaneous scarification. Nine (34.6%) patients died. Traditional cutaneous scarification was significantly associated with cutaneous superinfection, respiratory, systemic involvement, and death. CONCLUSION: Our case series points to increased complications and worse outcome of cutaneous anthrax disease if treated with skin scarification.


Assuntos
Antraz , Bacillus anthracis , Dermatopatias Bacterianas , Criança , Humanos , Angola , Antraz/diagnóstico , Antraz/tratamento farmacológico , Antraz/epidemiologia , Antibacterianos/uso terapêutico , Dermatopatias Bacterianas/tratamento farmacológico , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/diagnóstico , Estudos Retrospectivos
7.
J Mater Chem B ; 12(2): 466-474, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38086684

RESUMO

In this study, a rare-earth hybrid luminescent material (lanthanide@COF) was constructed for the detection of a biomarker for anthrax (dipicolinic acid, DPA). JCU-505-COOH was prepared by the hydrolysis of the cyano group in JCU-505 via a post-synthetic modification strategy, then the carboxyl groups in JCU-505-COOH coordinated with Tb3+ ions, similar to pincer vising nut. The prepared Tb3+@JCU-505-COOH exhibited a turn-on response toward DPA, which allowed the lanthanide@COF to serve as a fluorescence sensor with excellent selectivity and high sensitivity (binding constant Ka = 3.66 × 103). The fluorescent probe showed satisfactory performance for the determination of DPA in saliva and urine with a detection limit of 0.6 µM. Moreover, we established a facile point-of-care testing (POCT) using the Tb3+@JCU-505-COOH-based fluorescent test paper together with a smartphone for the initial diagnosis of anthrax. As expected, Tb3+@JCU-505-COOH showed great potential for the rapid screening of anthrax due to low cost, simple operation, and wide applicability.


Assuntos
Antraz , Bacillus anthracis , Elementos da Série dos Lantanídeos , Humanos , Antraz/diagnóstico , Biomarcadores
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 308: 123785, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38134652

RESUMO

A novel dual-emission fluorescent nanoprobe based on rare-earth nanosheets was fabricated to detect 2,6-pyridine dicarboxylic acid (DPA), which is the biomarker of Bacillus anthracis. 2-amino terephthalic acid (BDC-NH2) and surfactant sodium dodecyl sulfate (SDS) were co-intercalated into layered europium hydroxide (LEuH) to prepare the organic/inorganic composite, which was delaminated to obtain the rare-earth nanosheets. The ratio detection of DPA is possible due to the antenna effect between DPA and Eu3+. The nanoprobe shows high accuracy and sensitivity due to the large specific surface area of the rare-earth nanosheets. The limit of detection (LOD) is 4.4 nM for DPA in the range of 0-20 µM. In addition, a more convenient and faster smartphone-based visual detection platform was established based on the obvious color change. This work offers an effective way for developing visual sensing platforms, which opens a new path for designing fluorescent probes with superior sensing capabilities.


Assuntos
Antraz , Bacillus anthracis , Humanos , Antraz/diagnóstico , Smartphone , Európio , Corantes Fluorescentes , Biomarcadores
9.
MMWR Recomm Rep ; 72(6): 1-47, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37963097

RESUMO

This report updates previous CDC guidelines and recommendations on preferred prevention and treatment regimens regarding naturally occurring anthrax. Also provided are a wide range of alternative regimens to first-line antimicrobial drugs for use if patients have contraindications or intolerances or after a wide-area aerosol release of: Bacillus anthracis spores if resources become limited or a multidrug-resistant B. anthracis strain is used (Hendricks KA, Wright ME, Shadomy SV, et al.; Workgroup on Anthrax Clinical Guidelines. Centers for Disease Control and Prevention expert panel meetings on prevention and treatment of anthrax in adults. Emerg Infect Dis 2014;20:e130687; Meaney-Delman D, Rasmussen SA, Beigi RH, et al. Prophylaxis and treatment of anthrax in pregnant women. Obstet Gynecol 2013;122:885-900; Bradley JS, Peacock G, Krug SE, et al. Pediatric anthrax clinical management. Pediatrics 2014;133:e1411-36). Specifically, this report updates antimicrobial drug and antitoxin use for both postexposure prophylaxis (PEP) and treatment from these previous guidelines best practices and is based on systematic reviews of the literature regarding 1) in vitro antimicrobial drug activity against B. anthracis; 2) in vivo antimicrobial drug efficacy for PEP and treatment; 3) in vivo and human antitoxin efficacy for PEP, treatment, or both; and 4) human survival after antimicrobial drug PEP and treatment of localized anthrax, systemic anthrax, and anthrax meningitis. Changes from previous CDC guidelines and recommendations include an expanded list of alternative antimicrobial drugs to use when first-line antimicrobial drugs are contraindicated or not tolerated or after a bioterrorism event when first-line antimicrobial drugs are depleted or ineffective against a genetically engineered resistant: B. anthracis strain. In addition, these updated guidelines include new recommendations regarding special considerations for the diagnosis and treatment of anthrax meningitis, including comorbid, social, and clinical predictors of anthrax meningitis. The previously published CDC guidelines and recommendations described potentially beneficial critical care measures and clinical assessment tools and procedures for persons with anthrax, which have not changed and are not addressed in this update. In addition, no changes were made to the Advisory Committee on Immunization Practices recommendations for use of anthrax vaccine (Bower WA, Schiffer J, Atmar RL, et al. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Recomm Rep 2019;68[No. RR-4]:1-14). The updated guidelines in this report can be used by health care providers to prevent and treat anthrax and guide emergency preparedness officials and planners as they develop and update plans for a wide-area aerosol release of B. anthracis.


Assuntos
Vacinas contra Antraz , Antraz , Anti-Infecciosos , Antitoxinas , Bacillus anthracis , Meningite , Adulto , Humanos , Feminino , Criança , Gravidez , Estados Unidos/epidemiologia , Antraz/diagnóstico , Antraz/tratamento farmacológico , Antraz/prevenção & controle , Vacinas contra Antraz/uso terapêutico , Vacinas contra Antraz/efeitos adversos , Anti-Infecciosos/uso terapêutico , Antitoxinas/farmacologia , Antitoxinas/uso terapêutico , Centers for Disease Control and Prevention, U.S. , Aerossóis/farmacologia , Aerossóis/uso terapêutico , Meningite/induzido quimicamente , Meningite/tratamento farmacológico
10.
Mikrochim Acta ; 190(12): 484, 2023 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-38006440

RESUMO

Developing an intelligent, sensitive, and visual strategy for quickly identifying anthrax biomarkers is crucial for ensuring food safety and preventing disease outbreaks. Herein, a smartphone-integrated ratiometric fluorescent sensing platform based on bimetallic metal-organic framework (Eux/Tb1-x-MOF) nanowires was designed for specific recognition of pyridine-2,6-dicarboxylic acid (DPA, anthrax biomarker). The Eux/Tb1-x-MOF was prepared by coordinating Eu3+ and Tb3+ with BBDC ligands, which exhibited a uniform fibrous morphology and dual-emission fluorescence at 543 and 614 nm. After the introduction of DPA, the red emission at 614 nm displayed obvious fluorescence quenching, while the green emission at 543 nm was gradually enhanced. The ratiometric sensing offered a wide linear equation in the range of 0.06-15 µg/mL and a low detection limit (LOD) of 20.69 ng/mL. Furthermore, a portable smartphone installing the color recognition application can achieve sensitive, real-time, and visual detection of DPA. As a simple and effective smartphone-assisted sensing platform, this work holds admirable promise to broaden the applications in biomarker real-time determinations and other fields.


Assuntos
Antraz , Estruturas Metalorgânicas , Nanofios , Humanos , Antraz/diagnóstico , Fluorescência , Corantes Fluorescentes , Smartphone , Biomarcadores
11.
Travel Med Infect Dis ; 56: 102659, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37926374

RESUMO

BACKGROUND: Anthrax is a zoonotic infection resulting from the bacteria Bacillus anthracis. Humans contract cutaneous anthrax by coming into contact, and gastrointestinal (GI) anthrax by consumption of infected animals or animal products. An outbreak investigation was conducted to confirm the occurrence of the anthrax outbreak, comprehend its extent, understand the epidemiological characteristics, identify the outbreak's cause, and propose control measures. METHODS: A descriptive epidemiology was carried out for this outbreak investigation. We defined a suspected human cutaneous anthrax case as appearance of skin lesions and symptoms (itching/redness/swelling) and a suspected case of GI anthrax as appearance of diarrhoea/abdominal pain/vomiting in a resident of Koraput district after being associated with slaughtering and/or consumption of carcass during 5th April to 15th May 2023. The etiological hypothesis was formulated using descriptive epidemiological methods. Laboratory confirmation was performed by real-time polymerase chain reaction (RT-PCR). Statistical analyses were conducted using SPSS 25. RESULTS: A total of 47 clinically suspected anthrax cases were identified during the outbreak in five villages of Koraput district in Odisha. The epidemic curve indicated multiple point-source exposures starting from 13th April 2023. About 10 cases were identified by RT-PCR testing as confirmed cases of anthrax. No death was recorded in this outbreak investigation. CONCLUSIONS: Based on a thorough examination of epidemiological survey results and laboratory findings, we conclude that the outbreak was of human cutaneous and GI anthrax. Exposures from handling dead animals were associated with cutaneous anthrax, whereas eating uncooked meat of dead sheep was associated with gastrointestinal anthrax.


Assuntos
Antraz , Humanos , Animais , Ovinos , Antraz/epidemiologia , Antraz/diagnóstico , Antraz/microbiologia , Vômito , Surtos de Doenças , Diarreia/epidemiologia , Índia/epidemiologia
12.
Molecules ; 28(18)2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37764333

RESUMO

Bacillus anthracis has gained international attention as a deadly bacterium and a potentially deadly biological warfare agent. Dipicolinic acid (DPA) is the main component of the protective layer of anthracis spores, and is also an anthrax biomarker. Therefore, it is of great significance to explore an efficient and sensitive DPA detection method. Herein, a novel ratio hybrid probe (CQDs-PIL-Eu3+) was prepared by a simple one-step hydrothermal method using carbon quantum dots (CQDs) as an internal reference fluorescence and a covalent bond between CQDs and Eu3+ by using a polyionic liquid (PIL) as a bridge molecule. The ratiometric fluorescence probe was found to have the characteristics of sensitive fluorescence visual sensing in detecting DPA. The structure and the sensing properties of CQDs-PIL-Eu3+ were investigated in detail. In particular, the fluorescence intensity ratio of Eu3+ to CQDs (I616/I440) was linear with the concentration of DPA in the range of 0-50 µM, so the detection limit of the probe was as low as 32 nm, which was far lower than the DPA dose released by the number of anthrax spores in human body (60 µM) and, thus, can achieve sensitive detection. Therefore, the ratiometric fluorescence probe in this work has the characteristics of strong anti-interference, visual sensing, and high sensitivity, which provides a very promising scheme for the realization of anthrax biomarker DPA detection.


Assuntos
Antraz , Pontos Quânticos , Humanos , Antraz/diagnóstico , Antraz/microbiologia , Európio/química , Corantes Fluorescentes/química , Pontos Quânticos/química , Fluorescência , Carbono/química , Biomarcadores/química
13.
Sensors (Basel) ; 23(13)2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37447669

RESUMO

BACKGROUND: Protective antigen (PA) is an important biomarker for the early diagnosis of anthrax, and the accurate detection of protective antigen under extremely low concentration conditions has always been a hot topic in the biomedical field. To complete the diagnosis of anthrax in a timely manner, it is necessary to detect PA at extremely low concentrations, as the amount of PA produced in the early stage of anthrax invasion is relatively small. Graphene field-effect transistor (Gr-FET) biosensors are a new type of material for preparing biosensors, with the advantages of a short detection time and ultra-low detection limit. METHODS: The effect of different concentrations of diluents on the affinity of PA monoclonal antibodies was determined via an ELISA experiment. Combined with the Debye equation, 0.01 × PBS solution was finally selected as the diluent for the experiment. Then, a PA monoclonal antibody was selected as the bio-recognition element to construct a Gr-FET device based on CVD-grown graphene, which was used to detect the concentration of PA while recording the response time, linear range, detection limit, and other parameters. RESULTS: The experimental results showed that the biosensor could quickly detect PA, with a linear range of 10 fg/mL to 100 pg/mL and a detection limit of 10 fg/mL. In addition, the biosensor showed excellent specificity and repeatability. CONCLUSIONS: By constructing a Gr-FET device based on CVD-grown graphene and selecting a PA monoclonal antibody as the bio-recognition element, a highly sensitive, specific, and repeatable Gr-FET biosensor was successfully prepared for detecting extremely low concentrations of anthrax protective antigen (PA). This biosensor is expected to have a wide range of applications in clinical medicine and biological safety monitoring.


Assuntos
Antraz , Técnicas Biossensoriais , Doenças Cardiovasculares , Grafite , Humanos , Antraz/diagnóstico , Técnicas Biossensoriais/métodos , Anticorpos Monoclonais
14.
Mikrochim Acta ; 190(8): 291, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37458835

RESUMO

The weak fluorescence efficiency of copper nanoclusters (Cu NCs) limits their wide applications in biosensing and bioimaging areas, while the aggregation-induced emission (AIE) effect is anticipated to increase their luminescence intensity. Herein, the weak red emission of Cu NCs is increased considerably by the addition of lanthanide Tb3+, ascribed to the AIE effect. Monitoring of spores contamination can be carried out by determining the level of 2, 6-dipicolinic acid (DPA), which is a marker of spores. Due to the stronger synergy between DPA and Tb3+ for its clamped configuration of adjacent pyridine nitrogen group with the carboxylic acid group, the addition of DPA leads Tb3+ to be taken away from Cu NCs through a stronger coordination effect, causing Cu NCs to return to the dispersed state and weakened fluorescence. Based on this, an "off-on-off" fluorescent probe for DPA sensing was built, in which Tb3+ was used as a bridge to achieve AIE enhanced fluorescence effect on Cu NCs as well as a specific recognizer of DPA. The detection range for DPA was 0.1-60 µM and the detection limit was 0.06 µM, which was much lower than the infectious dose of anthrax spores. Since DPA is a unique biomarker for bacterial spores, the method was applied to the detection of actual bacterial spores and satisfactory results were obtained with a detection limit of 4.9*103 CFU mL-1.


Assuntos
Antraz , Humanos , Antraz/diagnóstico , Cobre , Ácidos Picolínicos , Biomarcadores
16.
Analyst ; 148(14): 3379-3391, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37366050

RESUMO

Investigating effective fluorescence strategies for real-time monitoring of dipicolinic acid (DPA) is of paramount importance in safeguarding human health. Herein, we present the design of a desirable red-emissive carbon nanostructure anchoring a molecularly imprinted Er-BTC MOF as a fluorescence biosensor for the visual determination of DPA. DPA is a biomarker of Bacillus anthracis, a subcategory of serious infectious diseases and bioweapons. We introduce a paper test strip sensitized with the aforementioned nanostructure, which is integrated with online UV excitation and smartphone digital imaging, resulting in a DPA signal-off sensing platform. The proposed fluorometric visual paper-based biosensor demonstrates wide linear ranges for DPA (10-125 µM) with a LOQ and LOD of 4.32 and 1.28 µM, respectively. The designed platform exhibits impressive emission properties and adaptable surface functional groups, which confirm its desirable selective sensing capabilities against other biological molecules and DPA isomers. As a proof of concept, DPA monitoring is successfully applied to real samples of tap water and urine. This integrated selective paper-based nano-biosensor, coupled with smartphone signal recording, holds great promise for state-of-the-art practical applications including fluorometric/colorimetric detection in healthcare and environmental monitoring, food safety analysis, and point-of-care testing.


Assuntos
Antraz , Técnicas Biossensoriais , Nanoestruturas , Humanos , Antraz/diagnóstico , Európio/química , Corantes Fluorescentes/química , Carbono/química , Biomarcadores/análise , Ácidos Picolínicos/química
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 299: 122793, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37187145

RESUMO

A novel core-shell structure ratiometric fluorescent probe was developed, which can selectively and sensitively detect 2,6-dipicolinic acid (DPA) as an anthrax biomarker. Carbon dots (CDs) was embedded into SiO2 nanoparticles, which was acted as an internal reference signal. Tb3+ with green emission was connected to the carboxyl functionalized SiO2, which was acted as a responsive signal. With the addition of DPA, the emission of CDs at 340 nm was unchanged, while the fluorescence of Tb3+ at 544 nm was enhanced by the antenna effect. In the concentration range of 0.1-2 µM, the fluorescence intensity ratio of I544/I340 showed a good linear relationship with the concentration of DPA, and the limit of detection (LOD) was 10.2 nM. In addition, the dual-emission probe showed an obvious fluorescence color change from colourless to green with increasing DPA under UV light, which enabled visual detection.


Assuntos
Antraz , Pontos Quânticos , Humanos , Antraz/diagnóstico , Corantes Fluorescentes/química , Carbono/química , Dióxido de Silício/química , Biomarcadores , Pontos Quânticos/química
18.
Anal Chim Acta ; 1265: 341327, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37230572

RESUMO

The semiconductor-like characteristics and light absorption ability of metal-organic frameworks (MOFs) make it have the potential for photoelectrochemical sensing. Compared with composite and modified materials, the specific recognition of harmful substances directly using MOFs with suitable structures can undoubtedly simplify the fabrication of sensors. Herein, two photosensitive uranyl-organic frameworks (UOFs) named HNU-70 and HNU-71 were synthesized and explored as the novel "turn-on" photoelectrochemical sensors, which can be directly applied to monitor the biomarker of anthrax (dipicolinic acid). Both sensors have good selectivity and stability towards dipicolinic acid with the low detection limits of 1.062 and 1.035 nM, respectively, which are far lower than the human infection concentration. Moreover, they exhibit good applicability in the real physiological environment of human serum, demonstrating a good application prospect. Spectroscopic and electrochemical studies show that the mechanism of photocurrent enhancement results from the interaction between dipicolinic acid and UOFs, which facilitates the photogenerated electron transport.


Assuntos
Antraz , Estruturas Metalorgânicas , Humanos , Antraz/diagnóstico , Estruturas Metalorgânicas/química
19.
Talanta ; 261: 124664, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37209586

RESUMO

Bacillus anthracis spores can make humans infected with vicious anthrax, so it is significant to detect their biomarker 2,6-pyridinedicarboxylic acid (DPA). The development of dual-modal methods for DPA detection that are more flexible in practical applications remains a challenge. Herein, colorimetric xylenol orange (XO) was modified on fluorescent CdTe quantum dots (QDs) for dual-modal detection of DPA through competitive coordination. After the binding of XO on CdTe QDs via coordination with Cd2+, CdTe QDs displayed quenched red fluorescence and the bound XO was presented as red color. The competitive coordination of DPA with Cd2+ made XO released from CdTe QDs, causing the enhanced red fluorescence of CdTe QDs and the yellow color of free XO. On this basis, DPA was rapidly (1 min) quantified through fluorescent and colorimetric modes within the ranges of 0.1-5 µM and 0.5-40 µM, respectively. The detection limits for DPA were calculated as low as 42 nM and 240 nM, respectively assigned to fluorescent and colorimetric modes. The level of urinary DPA was further measured. Satisfactory relative standard deviations (fluorescent mode: 0.1%-10.2%, colorimetric mode: 0.8%-1.8%) and spiked recoveries (fluorescent mode: 100.0%-115.0%, colorimetric mode: 86.0%-96.6%) were obtained.


Assuntos
Antraz , Compostos de Cádmio , Pontos Quânticos , Humanos , Antraz/diagnóstico , Corantes Fluorescentes , Cádmio , Colorimetria , Telúrio , Espectrometria de Fluorescência/métodos , Biomarcadores
20.
Technol Health Care ; 31(S1): 283-292, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37066929

RESUMO

BACKGROUND: In recent years, inductively coupled plasma mass spectrometry (ICP-MS) has been widely used in the field of molecular biology because of its unique advantages. Anthrax is a widespread and long-standing infectious disease, which affects and restricts people's work and life seriously. OBJECTIVE: The study goal is to develop a new method for the detection of anthrax. METHODS: A rapid, sensitive and accurate method for the detection of anthrax characteristic DNA was proposed by combing gold nanoparticles (AuNPs) and inductively coupled plasma mass spectrometry. RESULTS: The linear range of this method is 100-2500 pmol/L and the limit of detection of 16.61 pmol/L. CONCLUSION: The proposed method has numerous advantages, including simplicity of operation, high sensitivity, and specificity, which provides a new idea for the detection of anthrax. Importantly, this methodology has good potential for the detection of other biological substances such as bacteria and viruses by changing the modification sequence on the nanoparticle probe.


Assuntos
Antraz , Nanopartículas Metálicas , Humanos , Ouro/química , Espectrometria de Massas/métodos , Nanopartículas Metálicas/química , Antraz/diagnóstico , DNA/análise , DNA/química , DNA/genética
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