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1.
Biosens Bioelectron ; 166: 112431, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32862842

RESUMO

Last few decades, viruses are a real menace to human safety. Therefore, the rapid identification of viruses should be one of the best ways to prevent an outbreak and important implications for medical healthcare. The recent outbreak of coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus which belongs to the single-stranded, positive-strand RNA viruses. The pandemic dimension spread of COVID-19 poses a severe threat to the health and lives of seven billion people worldwide. There is a growing urgency worldwide to establish a point-of-care device for the rapid detection of COVID-19 to prevent subsequent secondary spread. Therefore, the need for sensitive, selective, and rapid diagnostic devices plays a vital role in selecting appropriate treatments and to prevent the epidemics. During the last decade, electrochemical biosensors have emerged as reliable analytical devices and represent a new promising tool for the detection of different pathogenic viruses. This review summarizes the state of the art of different virus detection with currently available electrochemical detection methods. Moreover, this review discusses different fabrication techniques, detection principles, and applications of various virus biosensors. Future research also looks at the use of electrochemical biosensors regarding a potential detection kit for the rapid identification of the COVID-19.


Assuntos
Betacoronavirus , Técnicas Biossensoriais/instrumentação , Técnicas de Laboratório Clínico/instrumentação , Infecções por Coronavirus/diagnóstico , Técnicas Eletroquímicas/instrumentação , Pneumonia Viral/diagnóstico , Vírus/isolamento & purificação , Animais , Betacoronavirus/isolamento & purificação , Betacoronavirus/patogenicidade , Infecções por Coronavirus/virologia , Desenho de Equipamento , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Pandemias , Pneumonia Viral/virologia , Testes Imediatos , Vírus/patogenicidade
2.
Biosens Bioelectron ; 166: 112431, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: covidwho-654767

RESUMO

Last few decades, viruses are a real menace to human safety. Therefore, the rapid identification of viruses should be one of the best ways to prevent an outbreak and important implications for medical healthcare. The recent outbreak of coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus which belongs to the single-stranded, positive-strand RNA viruses. The pandemic dimension spread of COVID-19 poses a severe threat to the health and lives of seven billion people worldwide. There is a growing urgency worldwide to establish a point-of-care device for the rapid detection of COVID-19 to prevent subsequent secondary spread. Therefore, the need for sensitive, selective, and rapid diagnostic devices plays a vital role in selecting appropriate treatments and to prevent the epidemics. During the last decade, electrochemical biosensors have emerged as reliable analytical devices and represent a new promising tool for the detection of different pathogenic viruses. This review summarizes the state of the art of different virus detection with currently available electrochemical detection methods. Moreover, this review discusses different fabrication techniques, detection principles, and applications of various virus biosensors. Future research also looks at the use of electrochemical biosensors regarding a potential detection kit for the rapid identification of the COVID-19.


Assuntos
Betacoronavirus , Técnicas Biossensoriais/instrumentação , Técnicas de Laboratório Clínico/instrumentação , Infecções por Coronavirus/diagnóstico , Técnicas Eletroquímicas/instrumentação , Pneumonia Viral/diagnóstico , Vírus/isolamento & purificação , Animais , Betacoronavirus/isolamento & purificação , Betacoronavirus/patogenicidade , Infecções por Coronavirus/virologia , Desenho de Equipamento , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Pandemias , Pneumonia Viral/virologia , Testes Imediatos , Vírus/patogenicidade
3.
Biosens Bioelectron ; 169: 112604, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32980805

RESUMO

Virus severely endangers human life and health, and the detection of viruses is essential for the prevention and treatment of associated diseases. Metal-organic framework (MOF), a novel hybrid porous material which is bridged by the metal clusters and organic linkers, has become a promising biosensor platform for virus detection due to its outstanding properties including high surface area, adjustable pore size, easy modification, etc. However, the MOF-based sensing platforms for virus detection are rarely summarized. This review systematically divided the detection platforms into nucleic acid and immunological (antigen and antibody) detection, and the underlying sensing mechanisms were interpreted. The nucleic acid sensing was discussed based on the properties of MOF (such as metal ion, functional group, geometry structure, size, porosity, stability, etc.), revealing the relationship between the sensing performance and properties of MOF. Moreover, antibodies sensing based on the fluorescence detection and antigens sensing based on molecular imprinting or electrochemical immunoassay were highlighted. Furthermore, the remaining challenges and future development of MOF for virus detection were further discussed and proposed. This review will provide valuable references for the construction of sophisticated sensing platform for the detection of viruses, especially the 2019 coronavirus.


Assuntos
Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Viroses/virologia , Vírus/isolamento & purificação , Animais , Anticorpos Antivirais/análise , Antígenos Virais/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Modelos Moleculares , Impressão Molecular/instrumentação , Impressão Molecular/métodos , Ácidos Nucleicos/análise , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/métodos , Viroses/diagnóstico
4.
Biosens Bioelectron ; 167: 112494, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32791468

RESUMO

G-quadruplex is a non-canonical nucleic acid structure formed by the folding of guanine rich DNA or RNA. The conformation and function of G-quadruplex are determined by a number of factors, including the number and polarity of nucleotide strands, the type of cations and the binding targets. Recent studies led to the discovery of additional advantageous attributes of G-quadruplex with the potential to be used in novel biosensors, such as improved ligand binding and unique folding properties. G-quadruplex based biosensor can detect various substances, such as metal ions, organic macromolecules, proteins and nucleic acids with improved affinity and specificity compared to standard biosensors. The recently developed G-quadruplex based biosensors include electrochemical and optical biosensors. A novel G-quadruplex based biosensors also show better performance and broader applications in the detection of a wide spectrum of pathogens, including SARS-CoV-2, the causative agent of COVID-19 disease. This review highlights the latest developments in the field of G-quadruplex based biosensors, with particular focus on the G-quadruplex sequences and recent applications and the potential of G-quadruplex based biosensors in SARS-CoV-2 detection.


Assuntos
Betacoronavirus , Técnicas Biossensoriais/métodos , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Quadruplex G , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais/tendências , Técnicas de Laboratório Clínico/tendências , Colorimetria , Técnicas Eletroquímicas , Corantes Fluorescentes , Humanos , Pandemias
5.
Sensors (Basel) ; 20(16)2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32824787

RESUMO

Pandemics require a fast and immediate response to contain potential infectious carriers. In the recent 2020 Covid-19 worldwide pandemic, authorities all around the world have failed to identify potential carriers and contain it on time. Hence, a rapid and very sensitive testing method is required. Current diagnostic tools, reverse transcription PCR (RT-PCR) and real-time PCR (qPCR), have its pitfalls for quick pandemic containment such as the requirement for specialized professionals and instrumentation. Versatile electrochemical DNA/RNA sensors are a promising technological alternative for PCR based diagnosis. In an electrochemical DNA sensor, a nucleic acid hybridization event is converted into a quantifiable electrochemical signal. A critical challenge of electrochemical DNA sensors is sensitive detection of a low copy number of DNA/RNA in samples such as is the case for early onset of a disease. Signal amplification approaches are an important tool to overcome this sensitivity issue. In this review, the authors discuss the most recent signal amplification strategies employed in the electrochemical DNA/RNA diagnosis of pathogens.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Infecções por Coronavirus/diagnóstico , Técnicas Eletroquímicas , Pneumonia Viral/diagnóstico , Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA/isolamento & purificação , Epidemias/prevenção & controle , Humanos , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real
6.
Pediatr Endocrinol Rev ; 17(3): 235-242, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32741154

RESUMO

BACKGROUND: Gonadotropin and steroid concentrations obtained in various laboratories cannot often be compared because of methodological differences. AIMS: to determine reference intervals for FSH, LH, T, E2, F and DHEA-S according to age and sex during the first year of life. METHODS: 1236 healthy infants (1-365 days of age) were recruited at Hospital de Niños in Córdoba, Argentina. Serum samples were analyzed using electrochemiluminescence, Cobas e601 analyzer. Reference Intervals and their confidence limits were estimated. RESULTS: Female FSH levels were higher than in males. LH and T levels were higher in males. E2 levels showed a difference between sexes after 60 days of age. F levels showed a wide variation, without differences between sexes. DHEA-S levels were higher at birth and decreased during the first year. CONCLUSION: These reference intervals may help to increase the diagnostic power for the assessment of endocrine disorders during the first year of life.


Assuntos
Medições Luminescentes , Argentina , Desidroepiandrosterona , Técnicas Eletroquímicas , Estradiol , Feminino , Hormônio Foliculoestimulante , Humanos , Hidrocortisona , Lactente , Recém-Nascido , Hormônio Luteinizante , Masculino , Testosterona
7.
Biosens Bioelectron ; 166: 112436, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32750677

RESUMO

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Grafite , Pneumonia Viral/diagnóstico , Vírus/isolamento & purificação , Reações Antígeno-Anticorpo , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/tendências , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/estatística & dados numéricos , Colorimetria , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA Viral/análise , DNA Viral/genética , Técnicas Eletroquímicas , Desenho de Equipamento , Grafite/química , Humanos , Luminescência , Nanoestruturas/química , Hibridização de Ácido Nucleico , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Pontos Quânticos/química , Análise Espectral Raman , Ressonância de Plasmônio de Superfície , Virologia/métodos , Vírus/genética , Vírus/patogenicidade
8.
Ecotoxicol Environ Saf ; 204: 111004, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32768745

RESUMO

Consumption of seafood contaminated with ciguatoxins (CTXs) leads to a foodborne disease known as ciguatera. Primary producers of CTXs are epibenthic dinoflagellates of the genera Gambierdiscus and Fukuyoa. In this study, thirteen Gambierdiscus and Fukuyoa strains were cultured, harvested at exponential phase, and CTXs were extracted with an implemented rapid protocol. Microalgal extracts were obtained from pellets with a low cell abundance (20,000 cell/mL) and were then analyzed with magnetic bead (MB)-based immunosensing tools (colorimetric immunoassay and electrochemical immunosensor). It is the first time that these approaches are used to screen Gambierdiscus and Fukuyoa strains, providing not only a global indication of the presence of CTXs, but also the ability to discriminate between two series of congeners (CTX1B and CTX3C). Analysis of the microalgal extracts revealed the presence of CTXs in 11 out of 13 strains and provided new information about Gambierdiscus and Fukuyoa toxin profiles. The use of immunosensing tools in the analysis of microalgal extracts facilitates the elucidation of further knowledge regarding these dinoflagellate genera and can contribute to improved ciguatera risk assessment and management.


Assuntos
Ciguatoxinas/isolamento & purificação , Colorimetria/métodos , Dinoflagelados/química , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Ciguatoxinas/classificação , Especificidade da Espécie
9.
Ecotoxicol Environ Saf ; 204: 111066, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32781344

RESUMO

In this study, an iron-doped metal-organic framework (MOF) Fe/ZIF-8 was synthesized from ZIF-8 at room temperature. Direct carbonization of Fe/ZIF-8 under a nitrogen atmosphere produced nanoporous nitrogen doped carbon nanoparticles decorated with Fe component (Fe/NC). The Fe/NC exhibited a large surface area (1221.185 m2 g-1) and narrow pore-size distribution (3-5 nm). The nanoporous Fe/NC components along with Nafion were used to modify a glassy carbon electrode for the electrochemical determination of chloramphenicol and metronidazole via linear sweep voltammetry. Under optimal conditions, the reduction peak currents (observed at -0.237 V and -0.071 V vs. Ag/AgCl) of these analytes increased linearly with increasing chloramphenicol and metronidazole concentrations in the range of 0.1-100 µM and 0.5-30 µM, with the detection limits estimated to be 31 nM and 165 nM, respectively. This result was attributed to the large surface area, porous structure, high nitrogen content, and as well as the electrocatalytic effect of Fe atoms embeded in the carbon support. The proposed sensor was used for chloramphenicol and metronidazole analysis in samples, providing satisfactory results.


Assuntos
Carbono/química , Cloranfenicol/análise , Técnicas Eletroquímicas/métodos , Ferro/química , Estruturas Metalorgânicas/química , Metronidazol/análise , Nitrogênio/química , Animais , Cloranfenicol/urina , Eletrodos , Humanos , Limite de Detecção , Metronidazol/urina , Leite/química , Nanoporos , Soluções Oftálmicas/química , Porosidade , Comprimidos/química
10.
J Chromatogr A ; 1628: 461443, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822982

RESUMO

Sodium dodecyl sulfate (SDS) in proteomics samples needs to be removed and estimated prior to mass spectrometry (MS)-based analysis and to avoid MS ion-source contamination. Here, we describe an organic solvent free method to remove SDS using a simple apparatus that mainly consists of an agarose gel inside a 1 mL plastic micropipette tip and a voltage power supply with electrodes. A small volume of sample (e.g., 50 µL) is loaded on top of the gel and then voltage (cathode at the sample side) is applied with an acidic solution at the other end of the micropipette tip. Within 25 min, SDS was removed (e.g., ≥99% SDS in 3.5 mM SDS) and the peptides were retained in the sample solution. The strategy was compared to the commercially available and expensive Pierce spin column for the removal of SDS and recovery of peptides from a digested bovine serum albumin sample.


Assuntos
Técnicas de Química Analítica/métodos , Técnicas Eletroquímicas , Proteômica/métodos , Dodecilsulfato de Sódio/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Espectrometria de Massas , Peptídeos/química , Soroalbumina Bovina/química , Dodecilsulfato de Sódio/química
11.
ACS Sens ; 5(9): 2747-2752, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32820626

RESUMO

With the current intense need for rapid and accurate detection of viruses due to COVID-19, we report on a platform technology that is well suited for this purpose, using intact measles virus for a demonstration. Cases of infection due to the measles virus are rapidly increasing, yet current diagnostic tools used to monitor for the virus rely on slow (>1 h) technologies. Here, we demonstrate the first biosensor capable of detecting the measles virus in minutes with no preprocessing steps. The key sensing element is an electrode coated with a self-assembled monolayer containing the measles antibody, immobilized through an N-heterocyclic carbene (NHC). The intact virus is detected by changes in resistance, giving a linear response to 10-100 µg/mL of the intact measles virus without the need to label or process the sample. The limit of detection is 6 µg/mL, which is at the lower limit of concentrations that can cause infections in primates. The NHC-based biosensors are shown to be superior to thiol-based systems, producing an approximately 10× larger response and significantly greater stability toward repeated measurements and long-term storage. This NHC-based biosensor thus represents an important development for both the rapid detection of the measles virus and as a platform technology for the detection of other biological targets of interest.


Assuntos
Anticorpos Imobilizados/imunologia , Benzimidazóis/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Vírus do Sarampo/isolamento & purificação , Anticorpos Imobilizados/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Limite de Detecção , Vírus do Sarampo/imunologia
12.
PLoS One ; 15(8): e0238061, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32846429

RESUMO

The method of non-aqueous conductivity titration (NACT) of organic weak acids was applied to quickly and accurately determine the phenolic-hydroxyl and carboxyl-groups contents in humic acid. By varying the pH of the humic-acid sample, the concentration of the titrant, and the nitrogen-gas flow rate, the optimal titration conditions were determined to be a sample pH of 4, titrant concentration of 0.05 mol/L, and nitrogen-gas flow rate of 80 mL/min. Applying the detection method to p-hydroxybenzoic acid showed that its phenolic-hydroxyl content was 758.82±111.76 cmol/kg and carboxyl content was 744.44±51.11 cmol/kg. The theoretical phenolic-hydroxyl and carboxyl-groups contents of the p-hydroxybenzoic acid were 723.96 cmol/kg respectively, indicating that the method can accurately quantify the carboxyl and phenolic-hydroxyl groups in the sample. The NACT was used to measure the phenolic-hydroxyl and carboxyl-groups contents in humic acid quickly and accurately. In addition, 29 humic acid samples from 8 provinces of China covering the main humic-acid producing areas were collected and analyzed for acidic-groups content using the reported method.


Assuntos
Técnicas Eletroquímicas/métodos , Substâncias Húmicas/análise , China , Condutividade Elétrica , Eletrodos , Concentração de Íons de Hidrogênio , Hidroxibenzoatos/análise , Fenóis/química , Solo/química
13.
ACS Sens ; 5(9): 2747-2752, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: covidwho-740029

RESUMO

With the current intense need for rapid and accurate detection of viruses due to COVID-19, we report on a platform technology that is well suited for this purpose, using intact measles virus for a demonstration. Cases of infection due to the measles virus are rapidly increasing, yet current diagnostic tools used to monitor for the virus rely on slow (>1 h) technologies. Here, we demonstrate the first biosensor capable of detecting the measles virus in minutes with no preprocessing steps. The key sensing element is an electrode coated with a self-assembled monolayer containing the measles antibody, immobilized through an N-heterocyclic carbene (NHC). The intact virus is detected by changes in resistance, giving a linear response to 10-100 µg/mL of the intact measles virus without the need to label or process the sample. The limit of detection is 6 µg/mL, which is at the lower limit of concentrations that can cause infections in primates. The NHC-based biosensors are shown to be superior to thiol-based systems, producing an approximately 10× larger response and significantly greater stability toward repeated measurements and long-term storage. This NHC-based biosensor thus represents an important development for both the rapid detection of the measles virus and as a platform technology for the detection of other biological targets of interest.


Assuntos
Anticorpos Imobilizados/imunologia , Benzimidazóis/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Vírus do Sarampo/isolamento & purificação , Anticorpos Imobilizados/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Limite de Detecção , Vírus do Sarampo/imunologia
14.
PLoS One ; 15(8): e0237583, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804936

RESUMO

Identification and quantification of plant flavonoids are critical to pharmacokinetic study and pharmaceutical quality control due to their distinct pharmacological functions. Here we report on a novel plant flavonoid electrochemical sensor for sensitive and selective detection of dihydromyricetin (DMY) based on double- layered membranes consisting of gold nanoparticles (Au) anchored on reduced graphene oxide (rGO) and molecularly imprinted polymers (MIPs) modified glassy carbon electrode (GCE). Both rGO-Au and MIPs membranes were directly formed on GCE via in-situ electrochemical reduction and polymerization processes step by step. The compositions, morphologies, and electrochemical properties of membranes were investigated with X-ray powder diffractometry (XRD), Fourier transform infrared spectrum (FTIR), Field emission scanning electron microscopy (FESEM) combined with various electrochemical methods. The fabricated electrochemical sensor labeled as GCE│rGO-Au/MIPs exhibited excellent performance in determining of DMY under optimal experimental conditions. A wide linear detection range (LDR) ranges from 2.0×10-8 to 1.0×10-4 M together with a low limit of detection (LOD) of 1.2×10-8 M (S/N = 3) were achieved. Moreover, the electrochemical sensor was employed to determine DMY in real samples with satisfactory results.


Assuntos
Carbono/química , Técnicas Eletroquímicas/instrumentação , Flavonoides/análise , Flavonóis/análise , Grafite/química , Técnicas Biossensoriais/métodos , Eletrodos , Ouro , Limite de Detecção , Nanopartículas Metálicas , Impressão Molecular , Extratos Vegetais/análise , Polímeros/síntese química , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
15.
Sensors (Basel) ; 20(16)2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: covidwho-721520

RESUMO

Pandemics require a fast and immediate response to contain potential infectious carriers. In the recent 2020 Covid-19 worldwide pandemic, authorities all around the world have failed to identify potential carriers and contain it on time. Hence, a rapid and very sensitive testing method is required. Current diagnostic tools, reverse transcription PCR (RT-PCR) and real-time PCR (qPCR), have its pitfalls for quick pandemic containment such as the requirement for specialized professionals and instrumentation. Versatile electrochemical DNA/RNA sensors are a promising technological alternative for PCR based diagnosis. In an electrochemical DNA sensor, a nucleic acid hybridization event is converted into a quantifiable electrochemical signal. A critical challenge of electrochemical DNA sensors is sensitive detection of a low copy number of DNA/RNA in samples such as is the case for early onset of a disease. Signal amplification approaches are an important tool to overcome this sensitivity issue. In this review, the authors discuss the most recent signal amplification strategies employed in the electrochemical DNA/RNA diagnosis of pathogens.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Infecções por Coronavirus/diagnóstico , Técnicas Eletroquímicas , Pneumonia Viral/diagnóstico , Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA/isolamento & purificação , Epidemias/prevenção & controle , Humanos , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real
16.
Biosens Bioelectron ; 167: 112494, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: covidwho-694826

RESUMO

G-quadruplex is a non-canonical nucleic acid structure formed by the folding of guanine rich DNA or RNA. The conformation and function of G-quadruplex are determined by a number of factors, including the number and polarity of nucleotide strands, the type of cations and the binding targets. Recent studies led to the discovery of additional advantageous attributes of G-quadruplex with the potential to be used in novel biosensors, such as improved ligand binding and unique folding properties. G-quadruplex based biosensor can detect various substances, such as metal ions, organic macromolecules, proteins and nucleic acids with improved affinity and specificity compared to standard biosensors. The recently developed G-quadruplex based biosensors include electrochemical and optical biosensors. A novel G-quadruplex based biosensors also show better performance and broader applications in the detection of a wide spectrum of pathogens, including SARS-CoV-2, the causative agent of COVID-19 disease. This review highlights the latest developments in the field of G-quadruplex based biosensors, with particular focus on the G-quadruplex sequences and recent applications and the potential of G-quadruplex based biosensors in SARS-CoV-2 detection.


Assuntos
Betacoronavirus , Técnicas Biossensoriais/métodos , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Quadruplex G , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais/tendências , Técnicas de Laboratório Clínico/tendências , Colorimetria , Técnicas Eletroquímicas , Corantes Fluorescentes , Humanos , Pandemias
17.
Biosens Bioelectron ; 166: 112436, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: covidwho-665846

RESUMO

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Grafite , Pneumonia Viral/diagnóstico , Vírus/isolamento & purificação , Reações Antígeno-Anticorpo , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/tendências , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/estatística & dados numéricos , Colorimetria , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA Viral/análise , DNA Viral/genética , Técnicas Eletroquímicas , Desenho de Equipamento , Grafite/química , Humanos , Luminescência , Nanoestruturas/química , Hibridização de Ácido Nucleico , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Pontos Quânticos/química , Análise Espectral Raman , Ressonância de Plasmônio de Superfície , Virologia/métodos , Vírus/genética , Vírus/patogenicidade
18.
Chemosphere ; 255: 127013, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679631

RESUMO

In order to obtain higher agricultural yields, the use of chemical substances has been increased to prevent the proliferation of pests, as well as ensuring durability in the storage of the food produced. Such substances are known as pesticides that may well present risks to human health and the environment. In the presence of metal ions, these substances can interact forming new species with different characteristics. Carbendazim (MBC) is an example of a harmful pesticide, which has atoms of nitrogen and oxygen in its structure that can form complexes with metal ions. Thus, in this work has studied the interaction between the copper (II) metal ion and carbendazim and its formation in natural water. The Cu-MBC complex showed a reduction peak of 0.007 V and an oxidation peak of 0.500 V, with characteristics of a quasi-reversible process under a glassy carbon electrode. By anodic stripping voltammetry, a different behavior was observed in the interaction of copper and carbendazim in ultrapure water and Billings dam water; however, it was possible to observe the complex in both samples. Carbendazim in the presence of the metal shows lower oxidation potential value, indicating the influence of the metal on the electrochemical response of the pesticide.


Assuntos
Benzimidazóis/química , Carbamatos/química , Cobre/química , Poluentes Químicos da Água/química , Carbono/química , Técnicas Eletroquímicas/métodos , Eletrodos , Oxirredução
19.
Nat Commun ; 11(1): 3743, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32719350

RESUMO

Ions are ubiquitous biological regulators playing a key role for vital processes in animals and plants. The combined detection of ion concentration and real-time monitoring of small variations with respect to the resting conditions is a multiscale functionality providing important information on health states. This multiscale functionality is still an open challenge for current ion sensing approaches. Here we show multiscale real-time and high-sensitivity ion detection with complementary organic electrochemical transistors amplifiers. The ion-sensing amplifier integrates in the same device both selective ion-to-electron transduction and local signal amplification demonstrating a sensitivity larger than 2300 mV V-1 dec-1, which overcomes the fundamental limit. It provides both ion detection over a range of five orders of magnitude and real-time monitoring of variations two orders of magnitude lower than the detected concentration, viz. multiscale ion detection. The approach is generally applicable to several transistor technologies and opens opportunities for multifunctional enhanced bioelectronics.


Assuntos
Amplificadores Eletrônicos , Sistemas Computacionais , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Íons/análise , Compostos Orgânicos/química , Transistores Eletrônicos , Eletricidade , Humanos , Íons/sangue , Potássio/análise
20.
Biosens Bioelectron ; 165: 112435, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32729548

RESUMO

COVID-19 is the shocking viral pandemics of this year which affected the health, economy, communications, and all aspects of social activities all over the world. Early diagnosis of this viral disease is very important since it can prevent lots of mortalities and care consumption. The functional similarities between COVID-19 and COVID-2 in inducing acute respiratory syndrome lightened our mind to find a diagnostic mechanism based on early traces of mitochondrial ROS overproduction as lung cells' dysfunctions induced by the virus. We designed a simple electrochemical sensor to selectively detect the intensity of ROS in the sputum sample (with a volume of less than 500 µl). Comparing the results of the sensor with clinical diagnostics of more than 140 normal and involved cases resulted in a response calibration with accuracy and sensitivity both 97%. Testing the sensor in more than 4 hospitals shed promising lights in ROS based real-time tracing of COVID-19 from the sputum sample.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais/métodos , Infecções por Coronavirus/diagnóstico , Técnicas Eletroquímicas/métodos , Pneumonia Viral/diagnóstico , Espécies Reativas de Oxigênio/análise , Escarro/virologia , Adulto , Idoso , Técnicas Biossensoriais/instrumentação , Infecções por Coronavirus/virologia , Diagnóstico Precoce , Técnicas Eletroquímicas/instrumentação , Desenho de Equipamento , Feminino , Humanos , Pulmão/química , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , Sensibilidade e Especificidade , Escarro/química , Adulto Jovem
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