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1.
Molecules ; 26(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34361791

RESUMO

As a key enzyme regulating postprandial blood glucose, α-Glucosidase is considered to be an effective target for the treatment of diabetes mellitus. In this study, a simple, rapid, and effective method for enzyme inhibitors screening assay was established based on α-glucosidase catalyzes reactions in a personal glucose meter (PGM). α-glucosidase catalyzes the hydrolysis of maltose to produce glucose, which triggers the reduction of ferricyanide (K3[Fe(CN)6]) to ferrocyanide (K4[Fe(CN)6]) and generates the PGM detectable signals. When the α-glucosidase inhibitor (such as acarbose) is added, the yield of glucose and the readout of PGM decreased accordingly. This method can achieve the direct determination of α-glucosidase activity by the PGM as simple as the blood glucose tests. Under the optimal experimental conditions, the developed method was applied to evaluate the inhibitory activity of thirty-four small-molecule compounds and eighteen medicinal plants extracts on α-glucosidase. The results exhibit that lithospermic acid (52.5 ± 3.0%) and protocatechualdehyde (36.8 ± 2.8%) have higher inhibitory activity than that of positive control acarbose (31.5 ± 2.5%) at the same final concentration of 5.0 mM. Besides, the lemon extract has a good inhibitory effect on α-glucosidase with a percentage of inhibition of 43.3 ± 3.5%. Finally, the binding sites and modes of four active small-molecule compounds to α-glucosidase were investigated by molecular docking analysis. These results indicate that the PGM method is feasible to screening inhibitors from natural products with simple and rapid operations.


Assuntos
Benzaldeídos/farmacologia , Benzofuranos/farmacologia , Glicemia/análise , Catecóis/farmacologia , Depsídeos/farmacologia , Diabetes Mellitus Tipo 2/diagnóstico , Inibidores de Glicosídeo Hidrolases/farmacologia , Monitorização Ambulatorial/métodos , alfa-Glucosidases/sangue , Acarbose/química , Acarbose/farmacologia , Benzaldeídos/química , Benzaldeídos/isolamento & purificação , Benzofuranos/química , Benzofuranos/isolamento & purificação , Sítios de Ligação , Técnicas Biossensoriais/instrumentação , Catecóis/química , Catecóis/isolamento & purificação , Depsídeos/química , Depsídeos/isolamento & purificação , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores de Glicosídeo Hidrolases/química , Humanos , Hidrólise , Cinética , Maltose/metabolismo , Simulação de Acoplamento Molecular , Monitorização Ambulatorial/instrumentação , Extratos Vegetais/química , Plantas Medicinais , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Termodinâmica , Dispositivos Eletrônicos Vestíveis , alfa-Glucosidases/química
2.
Nat Commun ; 12(1): 5008, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34429436

RESUMO

Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient demonstrate the feasibility, functionality and long-term stability of this technology in operating hospital settings.


Assuntos
Técnicas Biossensoriais/métodos , Fontes de Energia Elétrica , Pressão , Temperatura , Tecnologia sem Fio , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Pele , Termografia/instrumentação , Termografia/métodos
3.
Nat Commun ; 12(1): 4876, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385436

RESUMO

While the printed circuit board (PCB) has been widely considered as the building block of integrated electronics, the world is switching to pursue new ways of merging integrated electronic circuits with textiles to create flexible and wearable devices. Herein, as an alternative for PCB, we described a non-printed integrated-circuit textile (NIT) for biomedical and theranostic application via a weaving method. All the devices are built as fibers or interlaced nodes and woven into a deformable textile integrated circuit. Built on an electrochemical gating principle, the fiber-woven-type transistors exhibit superior bending or stretching robustness, and were woven as a textile logical computing module to distinguish different emergencies. A fiber-type sweat sensor was woven with strain and light sensors fibers for simultaneously monitoring body health and the environment. With a photo-rechargeable energy textile based on a detailed power consumption analysis, the woven circuit textile is completely self-powered and capable of both wireless biomedical monitoring and early warning. The NIT could be used as a 24/7 private AI "nurse" for routine healthcare, diabetes monitoring, or emergencies such as hypoglycemia, metabolic alkalosis, and even COVID-19 patient care, a potential future on-body AI hardware and possibly a forerunner to fabric-like computers.


Assuntos
Técnicas Biossensoriais/instrumentação , Medicina de Precisão/instrumentação , Têxteis , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio/instrumentação , Técnicas Biossensoriais/métodos , COVID-19/diagnóstico , COVID-19/prevenção & controle , COVID-19/virologia , Desenho de Equipamento , Humanos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Medicina de Precisão/métodos , SARS-CoV-2/fisiologia , Suor/fisiologia
4.
Molecules ; 26(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198893

RESUMO

In this work, a low-cost and rapid electrochemical resistive DNA biosensor based on the current relaxation method is described. A DNA probe, complementary to the specific human papillomavirus type 16 (HPV-16) sequence, was immobilized onto a screen-printed gold electrode. DNA hybridization was detected by applying a potential step of 30 mV to the system, composed of an external capacitor and the modified electrode DNA/gold, for 750 µs and then relaxed back to the OCP, at which point the voltage and current discharging curves are registered for 25 ms. From the discharging curves, the potential and current relaxation were evaluated, and by using Ohm's law, the charge transfer resistance through the DNA-modified electrode was calculated. The presence of a complementary sequence was detected by the change in resistance when the ssDNA is transformed in dsDNA due to the hybridization event. The target DNA concentration was detected in the range of 5 to 20 nM. The results showed a good fit to the regression equation ΔRtotal(Ω)=2.99 × [DNA]+81.55, and a detection limit of 2.39 nM was obtained. As the sensing approach uses a direct current, the electronic architecture of the biosensor is simple and allows for the separation of faradic and nonfaradaic contributions. The simple electrochemical resistive biosensor reported here is a good candidate for the point-of-care diagnosis of HPV at a low cost and in a short detection time.


Assuntos
Técnicas Biossensoriais/instrumentação , DNA Viral/análise , Papillomavirus Humano 16/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Papillomavirus Humano 16/genética , Humanos , Limite de Detecção , Testes Imediatos
5.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207397

RESUMO

The review covers some research conducted in the field of medical and biomedical application of devices based on silicon sensor elements (Si-NW-sensors). The use of Si-NW-sensors is one of the key methods used in a whole range of healthcare fields. Their biomedical use is among the most important ones as they offer opportunities for early diagnosis of oncological pathologies, for monitoring the prescribed therapy and for improving the people's quality of life.


Assuntos
Técnicas Biossensoriais/instrumentação , Detecção Precoce de Câncer/instrumentação , Nanofios/química , Neoplasias/diagnóstico , Silício/química , Humanos , Qualidade de Vida
6.
Nat Commun ; 12(1): 3741, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145296

RESUMO

Despite technological advances in biomolecule detections, evaluation of molecular interactions via potentiometric devices under ion-enriched solutions has remained a long-standing problem. To avoid severe performance degradation of bioelectronics by ionic screening effects, we cover probe surfaces of field effect transistors with a single film of the supported lipid bilayer, and realize respectable potentiometric signals from receptor-ligand bindings irrespective of ionic strength of bulky solutions by placing an ion-free water layer underneath the supported lipid bilayer. High-energy X-ray reflectometry together with the circuit analysis and molecular dynamics simulation discovered biochemical findings that effective electrical signals dominantly originated from the sub-nanoscale conformational change of lipids in the course of receptor-ligand bindings. Beyond thorough analysis on the underlying mechanism at the molecular level, the proposed supported lipid bilayer-field effect transistor platform ensures the world-record level of sensitivity in molecular detection with excellent reproducibility regardless of molecular charges and environmental ionic conditions.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Bicamadas Lipídicas/química , Potenciometria/instrumentação , Potenciometria/métodos , Membrana Celular/metabolismo , Lipídeos de Membrana/metabolismo , Simulação de Dinâmica Molecular , Concentração Osmolar , Transistores Eletrônicos
7.
Nat Commun ; 12(1): 3710, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-34140475

RESUMO

The growing need for the implementation of stretchable biosensors in the body has driven rapid prototyping schemes through the direct ink writing of multidimensional functional architectures. Recent approaches employ biocompatible inks that are dispensable through an automated nozzle injection system. However, their application in medical practices remains challenged in reliable recording due to their viscoelastic nature that yields mechanical and electrical hysteresis under periodic large strains. Herein, we report sponge-like poroelastic silicone composites adaptable for high-precision direct writing of custom-designed stretchable biosensors, which are soft and insensitive to strains. Their unique structural properties yield a robust coupling to living tissues, enabling high-fidelity recording of spatiotemporal electrophysiological activity and real-time ultrasound imaging for visual feedback. In vivo evaluations of custom-fit biosensors in a murine acute myocardial infarction model demonstrate a potential clinical utility in the simultaneous intraoperative recording and imaging on the epicardium, which may guide definitive surgical treatments.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Diagnóstico por Imagem/métodos , Infarto do Miocárdio/diagnóstico por imagem , Pericárdio/diagnóstico por imagem , Animais , Materiais Biocompatíveis/química , Linhagem Celular , Modelos Animais de Doenças , Eletrocardiografia , Fenômenos Eletrofisiológicos , Processamento de Imagem Assistida por Computador , Tinta , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Dinâmica Molecular , Mioblastos/metabolismo , Mioblastos/patologia , Próteses e Implantes , Silicones/química , Análise Espaço-Temporal , Suínos , Ultrassonografia
8.
Philos Trans R Soc Lond B Biol Sci ; 376(1831): 20200228, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34176326

RESUMO

The goal of achieving enhanced diagnosis and continuous monitoring of human health has led to a vibrant, dynamic and well-funded field of research in medical sensing and biosensor technologies. The field has many sub-disciplines which focus on different aspects of sensor science; engaging engineers, chemists, biochemists and clinicians, often in interdisciplinary teams. The trends which dominate include the efforts to develop effective point of care tests and implantable/wearable technologies for early diagnosis and continuous monitoring. This review will outline the current state of the art in a number of relevant fields, including device engineering, chemistry, nanoscience and biomolecular detection, and suggest how these advances might be employed to develop effective systems for measuring physiology, detecting infection and monitoring biomarker status in wild animals. Special consideration is also given to the emerging threat of antimicrobial resistance and in the light of the current SARS-CoV-2 outbreak, zoonotic infections. Both of these areas involve significant crossover between animal and human health and are therefore well placed to seed technological developments with applicability to both human and animal health and, more generally, the reviewed technologies have significant potential to find use in the measurement of physiology in wild animals. This article is part of the theme issue 'Measuring physiology in free-living animals (Part II)'.


Assuntos
Técnicas Biossensoriais/instrumentação , COVID-19/diagnóstico , Biologia Sintética/métodos , Dispositivos Eletrônicos Vestíveis , Infecção por Zika virus/veterinária , Zoonoses/diagnóstico , Animais , Animais Selvagens/microbiologia , Animais Selvagens/parasitologia , Animais Selvagens/virologia , Biomarcadores/análise , Engenharia Celular/métodos , Humanos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Testes Imediatos , Infecção por Zika virus/diagnóstico
9.
Food Chem ; 362: 130261, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111691

RESUMO

In this study, a novel surface enhanced Raman spectroscopy (SERS) sensor was developed for the ultrasensitive determination of kanamycin in foods. The sensor used two distinct signal amplification strategies, namely the surface plasmon resonance of gold nanorods and a Zn-doped carbon quantum dots catalytic cascade oxidation-reduction reaction switch controlled by a nucleic acid aptamer. Under optimized experimental conditions, the SERS sensor demonstrated a linear range of 10-12 to 10-5 g mL-1 for the detection of kanamycin, with a limit of detection of 3.03 × 10-13 g mL-1. Experiments with antibiotics structurally similar to kanamycin and interferrants revealed that the sensor had excellent selectivity. Milkpowder and honey samples spiked with kanamycin were assayed, with recoveries ranging from 84.1% to 107.2% and a relative standard deviation of 0.74% to 2.81% being obtained. Quantification of kanamycin in milk samples revealed no significant difference between the results obtained with the sensor and by HPLC.


Assuntos
Aptâmeros de Nucleotídeos/química , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Canamicina/análise , Nanotubos/química , Pontos Quânticos/química , Zinco/química , Antibacterianos/análise , Técnicas Biossensoriais/instrumentação , Carbono/química , Catálise , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Ressonância de Plasmônio de Superfície
10.
Chem Commun (Camb) ; 57(53): 6511-6513, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34105532

RESUMO

A closed bipolar electrode (BPE) based fluorescence visualization biosensor was successfully constructed and used for anti-interference detection of T-2 toxin.


Assuntos
Técnicas Biossensoriais/instrumentação , Fluorescência , Toxina T-2/análise , Eletrodos
11.
Nat Commun ; 12(1): 3293, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078903

RESUMO

Dielectric metasurfaces support resonances that are widely explored both for far-field wavefront shaping and for near-field sensing and imaging. Their design explores the interplay between localised and extended resonances, with a typical trade-off between Q-factor and light localisation; high Q-factors are desirable for refractive index sensing while localisation is desirable for imaging resolution. Here, we show that a dielectric metasurface consisting of a nanohole array in amorphous silicon provides a favourable trade-off between these requirements. We have designed and realised the metasurface to support two optical modes both with sharp Fano resonances that exhibit relatively high Q-factors and strong spatial confinement, thereby concurrently optimizing the device for both imaging and biochemical sensing. For the sensing application, we demonstrate a limit of detection (LOD) as low as 1 pg/ml for Immunoglobulin G (IgG); for resonant imaging, we demonstrate a spatial resolution below 1 µm and clearly resolve individual E. coli bacteria. The combined low LOD and high spatial resolution opens new opportunities for extending cellular studies into the realm of microbiology, e.g. for studying antimicrobial susceptibility.


Assuntos
Técnicas Biossensoriais/instrumentação , Espectroscopia Dielétrica/métodos , Imagem Molecular/métodos , Nanoestruturas/química , Silício/química , Análise de Célula Única/métodos , Espectroscopia Dielétrica/instrumentação , Escherichia coli/ultraestrutura , Humanos , Imunoglobulina G/ultraestrutura , Limite de Detecção , Imagem Molecular/instrumentação , Refratometria , Análise de Célula Única/instrumentação , Propriedades de Superfície
12.
Molecules ; 26(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063344

RESUMO

Safety and quality are key issues for the food industry. Consequently, there is growing demand to preserve the food chain and products against substances toxic, harmful to human health, such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices, such as electrochemical sensors/biosensors. Generally, conventional techniques are limited by long analyses, expensive and complex procedures, and skilled personnel. Therefore, developing performant electrochemical biosensors can significantly support the screening of food chains and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in food screening and their challenges.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Inocuidade dos Alimentos/métodos , Antibacterianos/análise , Cadeia Alimentar , Humanos , Praguicidas/análise , Toxinas Biológicas/análise
13.
JAMA ; 325(22): 2273-2284, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34077502

RESUMO

Importance: Continuous glucose monitoring (CGM) is recommended for patients with type 1 diabetes; observational evidence for CGM in patients with insulin-treated type 2 diabetes is lacking. Objective: To estimate clinical outcomes of real-time CGM initiation. Design, Setting, and Participants: Exploratory retrospective cohort study of changes in outcomes associated with real-time CGM initiation, estimated using a difference-in-differences analysis. A total of 41 753 participants with insulin-treated diabetes (5673 type 1; 36 080 type 2) receiving care from a Northern California integrated health care delivery system (2014-2019), being treated with insulin, self-monitoring their blood glucose levels, and having no prior CGM use were included. Exposures: Initiation vs noninitiation of real-time CGM (reference group). Main Outcomes and Measures: Ten end points measured during the 12 months before and 12 months after baseline: hemoglobin A1c (HbA1c); hypoglycemia (emergency department or hospital utilization); hyperglycemia (emergency department or hospital utilization); HbA1c levels lower than 7%, lower than 8%, and higher than 9%; 1 emergency department encounter or more for any reason; 1 hospitalization or more for any reason; and number of outpatient visits and telephone visits. Results: The real-time CGM initiators included 3806 patients (mean age, 42.4 years [SD, 19.9 years]; 51% female; 91% type 1, 9% type 2); the noninitiators included 37 947 patients (mean age, 63.4 years [SD, 13.4 years]; 49% female; 6% type 1, 94% type 2). The prebaseline mean HbA1c was lower among real-time CGM initiators than among noninitiators, but real-time CGM initiators had higher prebaseline rates of hypoglycemia and hyperglycemia. Mean HbA1c declined among real-time CGM initiators from 8.17% to 7.76% and from 8.28% to 8.19% among noninitiators (adjusted difference-in-differences estimate, -0.40%; 95% CI, -0.48% to -0.32%; P < .001). Hypoglycemia rates declined among real-time CGM initiators from 5.1% to 3.0% and increased among noninitiators from 1.9% to 2.3% (difference-in-differences estimate, -2.7%; 95% CI, -4.4% to -1.1%; P = .001). There were also statistically significant differences in the adjusted net changes in the proportion of patients with HbA1c lower than 7% (adjusted difference-in-differences estimate, 9.6%; 95% CI, 7.1% to 12.2%; P < .001), lower than 8% (adjusted difference-in-differences estimate, 13.1%; 95% CI, 10.2% to 16.1%; P < .001), and higher than 9% (adjusted difference-in-differences estimate, -7.1%; 95% CI, -9.5% to -4.6%; P < .001) and in the number of outpatient visits (adjusted difference-in-differences estimate, -0.4; 95% CI, -0.6 to -0.2; P < .001) and telephone visits (adjusted difference-in-differences estimate, 1.1; 95% CI, 0.8 to 1.4; P < .001). Initiation of real-time CGM was not associated with statistically significant changes in rates of hyperglycemia, emergency department visits for any reason, or hospitalizations for any reason. Conclusions and Relevance: In this retrospective cohort study, insulin-treated patients with diabetes selected by physicians for real-time continuous glucose monitoring compared with noninitiators had significant improvements in hemoglobin A1c and reductions in emergency department visits and hospitalizations for hypoglycemia, but no significant change in emergency department visits or hospitalizations for hyperglycemia or for any reason. Because of the observational study design, findings may have been susceptible to selection bias.


Assuntos
Técnicas Biossensoriais/métodos , Automonitorização da Glicemia/métodos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Adulto , Técnicas Biossensoriais/instrumentação , Automonitorização da Glicemia/estatística & dados numéricos , Intervalos de Confiança , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Hemoglobina A Glicada/análise , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Humanos , Hiperglicemia/sangue , Hiperglicemia/diagnóstico , Hiperglicemia/epidemiologia , Hipoglicemia/sangue , Hipoglicemia/diagnóstico , Hipoglicemia/epidemiologia , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Números Necessários para Tratar , Pontuação de Propensão , Estudos Retrospectivos , Viés de Seleção , Fatores de Tempo , Resultado do Tratamento
14.
Biosensors (Basel) ; 11(6)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073756

RESUMO

Despite collaborative efforts from all countries, coronavirus disease 2019 (COVID-19) pandemic has been continuing to spread globally, forcing the world into social distancing period, making a special challenge for public healthcare system. Before vaccine widely available, the best approach to manage severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is to achieve highest diagnostic accuracy by improving biosensor efficacy. For SARS-CoV-2 diagnostics, intensive attempts have been made by many scientists to ameliorate the drawback of current biosensors of SARS-CoV-2 in clinical diagnosis to offer benefits related to platform proposal, systematic analytical methods, system combination, and miniaturization. This review assesses ongoing research efforts aimed at developing integrated diagnostic tools to detect RNA viruses and their biomarkers for clinical diagnostics of SARS-CoV-2 infection and further highlights promising technology for SARS-CoV-2 specific diagnosis. The comparisons of SARS-CoV-2 biomarkers as well as their applicable biosensors in the field of clinical diagnosis were summarized to give scientists an advantage to develop superior diagnostic platforms. Furthermore, this review describes the prospects for this rapidly growing field of diagnostic research, raising further interest in analytical technology and strategic plan for future pandemics.


Assuntos
Técnicas Biossensoriais/instrumentação , Teste para COVID-19/instrumentação , SARS-CoV-2/isolamento & purificação , Animais , Técnicas Biossensoriais/métodos , Teste para COVID-19/métodos , Colorimetria/instrumentação , Colorimetria/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Desenho de Equipamento , Humanos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Testes Imediatos
15.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073858

RESUMO

The discovery or engineering of fungus-derived FAD-dependent glucose 1-dehydrogenase (FAD-GDH) is especially important in the fabrication and performance of glucose biosensors. In this study, a novel FAD-GDH gene, phylogenetically distantly with other FAD-GDHs from Aspergillus species, was identified. Additionally, the wild-type GDH enzyme, and its fusion enzyme (GDH-NL-CBM2) with a carbohydrate binding module family 2 (CBM2) tag attached by a natural linker (NL), were successfully heterogeneously expressed. In addition, while the GDH was randomly immobilized on the electrode by conventional methods, the GDH-NL-CBM2 was orientationally immobilized on the nanocellulose-modified electrode by the CBM2 affinity adsorption tag through a simple one-step approach. A comparison of the performance of the two electrodes demonstrated that both electrodes responded linearly to glucose in the range of 0.12 to 40.7 mM with a coefficient of determination R2 > 0.999, but the sensitivity of immobilized GDH-NL-CBM2 (2.1362 × 10-2 A/(M*cm2)) was about 1-fold higher than that of GDH (1.2067 × 10-2 A/(M*cm2)). Moreover, a lower detection limit (51 µM), better reproducibility (<5%) and stability, and shorter response time (≈18 s) and activation time were observed for the GDH-NL-CBM2-modified electrode. This facile and easy immobilization approach used in the preparation of a GDH biosensor may open up new avenues in the development of high-performance amperometric biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Ensaios Enzimáticos/métodos , Enzimas Imobilizadas/metabolismo , Flavina-Adenina Dinucleotídeo/metabolismo , Glucose 1-Desidrogenase/metabolismo , Glucose/análise , Animais , Aspergillus flavus/química , Aspergillus flavus/metabolismo , Técnicas Biossensoriais/instrumentação , Glicemia/análise , Eletrodos , Enzimas Imobilizadas/química , Escherichia coli/metabolismo , Fungos/química , Expressão Gênica , Glucose 1-Desidrogenase/química , Glucose 1-Desidrogenase/genética , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Filogenia , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Reprodutibilidade dos Testes , Alinhamento de Sequência , Temperatura
16.
Anal Bioanal Chem ; 413(16): 4277-4287, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34057556

RESUMO

A novel smartphone-based electrochemical cell sensor was developed to evaluate the toxicity of heavy metal ions, such as cadmium (Cd2+), lead (Pb2+), and mercury (Hg2+) ions on Hep G2 cells. The cell sensor was fabricated with reduced graphene oxide (RGO)/molybdenum sulfide (MoS2) composites to greatly improve the biological adaptability and amplify the electrochemical signals. Differential pulse voltammetry (DPV) was employed to measure the electrical signals induced by the toxicity of heavy metal ions. The results showed that Cd2+, Hg2+, and Pb2+ significantly reduced the viability of Hep G2 cells in a dose-dependent manner. The IC50 values obtained by this method were 49.83, 36.94, and 733.90 µM, respectively. A synergistic effect was observed between Cd2+ and Pb2+ and between Hg2+ and Pb2+, and an antagonistic effect was observed between Cd2+ and Hg2+, and an antagonistic effect at low doses and an additive effect at high doses were found in the ternary mixtures of Cd2+, Hg2+, and Pb2+. These electrochemical results were confirmed via MTT assay, SEM and TEM observation, and flow cytometry. Therefore, this new electrochemical cell sensor provided a more convenient, sensitive, and flexible toxicity assessment strategy than traditional cytotoxicity assessment methods.


Assuntos
Técnicas Biossensoriais/instrumentação , Cádmio/toxicidade , Chumbo/toxicidade , Mercúrio/toxicidade , Oryza/efeitos dos fármacos , Cádmio/análise , Sobrevivência Celular/efeitos dos fármacos , Técnicas Eletroquímicas/instrumentação , Células Hep G2 , Humanos , Chumbo/análise , Mercúrio/análise , Oryza/citologia , Smartphone , Testes de Toxicidade/instrumentação
17.
ACS Appl Mater Interfaces ; 13(22): 26394-26403, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34032400

RESUMO

Human bodily kinesthetic sensing is generally complicated and ever-changing due to the diversity of body deformation as well as the complexity of mechanical stimulus, which is different from the unidirectional mechanical motion. So, there exists a huge challenge for current flexible sensors to accurately differentiate and identify what kind of external mechanical stimulus is exerted via analyzing digital signals. Here, we report a flexible dual-interdigital-electrode sensor (FDES) that consists of two interdigital electrodes and a highly pressure-sensitive porous conductive sponge. The FDES can precisely identify multiple mechanical stimuli, e.g., pressing, positive bending, negative bending, X-direction stretching, and Y-direction stretching, and convert them into corresponding current variation signals. Moreover, the FDES exhibits other exceptional properties, such as high sensitivity, stretchability, large measurement range, and outstanding stability, accompanied by simple structural design and low-cost processing simultaneously. Additionally, our FDES successfully identifies various complex activities of the human body, which lays a foundation for the further development of multimode flexible sensors.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Condutividade Elétrica , Eletrodos , Monitorização Fisiológica/métodos , Dispositivos Eletrônicos Vestíveis , Humanos , Pressão , Resistência à Tração
18.
Anal Bioanal Chem ; 413(16): 4137-4159, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34008124

RESUMO

Coronavirus disease 2019 (COVID-19) pandemic is currently a serious global health threat. While conventional laboratory tests such as quantitative real-time polymerase chain reaction (qPCR), serology tests, and chest computerized tomography (CT) scan allow diagnosis of COVID-19, these tests are time-consuming and laborious, and are limited in resource-limited settings or developing countries. Point-of-care (POC) biosensors such as chip-based and paper-based biosensors are typically rapid, portable, cost-effective, and user-friendly, which can be used for COVID-19 in remote settings. The escalating demand for rapid diagnosis of COVID-19 presents a strong need for a timely and comprehensive review on the POC biosensors for COVID-19 that meet ASSURED criteria: Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, and Deliverable to end users. In the present review, we discuss the importance of rapid and early diagnosis of COVID-19 and pathogenesis of COVID-19 along with the key diagnostic biomarkers. We critically review the most recent advances in POC biosensors which show great promise for the detection of COVID-19 based on three main categories: chip-based biosensors, paper-based biosensors, and other biosensors. We subsequently discuss the key benefits of these biosensors and their use for the detection of antigen, antibody, and viral nucleic acids. The commercial POC biosensors for COVID-19 are critically compared. Finally, we discuss the key challenges and future perspectives of developing emerging POC biosensors for COVID-19. This review would be very useful for guiding strategies for developing and commercializing rapid POC tests to manage the spread of infections.Graphical abstract.


Assuntos
Técnicas Biossensoriais , Teste para COVID-19/métodos , COVID-19/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Anticorpos Antivirais/análise , Antígenos Virais/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Teste de Ácido Nucleico para COVID-19/métodos , Humanos , SARS-CoV-2/genética
19.
J Mater Chem B ; 9(23): 4608-4619, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34013310

RESUMO

Worldwide infections and fatalities caused by the SARS-CoV-2 virus and its variants responsible for COVID-19 have significantly impeded the economic growth of many nations. People in many nations have lost their livelihoods, it has severely impacted international relations and, most importantly, health infrastructures across the world have been tormented. This pandemic has already left footprints on human psychology, traits, and priorities and is certainly going to lead towards a new world order in the future. As always, science and technology have come to the rescue of the human race. The prevention of infection by instant and repeated cleaning of surfaces that are most likely to be touched in daily life and sanitization drives using medically prescribed sanitizers and UV irradiation of textiles are the first steps to breaking the chain of transmission. However, the real challenge is to develop and uplift medical infrastructure, such as diagnostic tools capable of prompt diagnosis and instant and economic medical treatment that is available to the masses. Two-dimensional (2D) materials, such as graphene, are atomic sheets that have been in the news for quite some time due to their unprecedented electronic mobilities, high thermal conductivity, appreciable thermal stability, excellent anchoring capabilities, optical transparency, mechanical flexibility, and a unique capability to integrate with arbitrary surfaces. These attributes of 2D materials make them lucrative for use as an active material platform for authentic and prompt (within minutes) disease diagnosis via electrical or optical diagnostic tools or via electrochemical diagnosis. We present the opportunities provided by 2D materials as a platform for SARS-CoV-2 diagnosis.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Teste para COVID-19/instrumentação , Teste para COVID-19/métodos , COVID-19/diagnóstico , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , SARS-CoV-2/isolamento & purificação , COVID-19/mortalidade , Humanos , Análise Espectral Raman , Transistores Eletrônicos
20.
Int J Nanomedicine ; 16: 3497-3508, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34045854

RESUMO

Purpose: The PML/RARα fusion gene as a leukemogenesis plays a significant role in clinical diagnosis of the early stage of acute promyelocytic leukemia (APL). Here, we present an electrochemical biosensor for PML/RARα fusion gene detection using carbon dots functionalized graphene oxide (CDs/GO) nanocomposites modified glassy carbon electrode (CDs/GO/GCE). Materials and Methods: In this work, the CDs/GO nanocomposites are produced through π-π stacking interaction and could be prepared in large quantities by a facile and economical way. The CDs/GO nanocomposites were decorated onto electrode surface to improve the electrochemical activity and as a bio-platform attracted the target deoxyribonucleic acid (DNA) probe simultaneously. Results: The CDs/GO/GCE was fabricated successfully and exhibits high electrochemical activity, good biocompatibility, and strong bioaffinity toward the target DNA sequences, compared with only the pristine CDs on GCE or GO on GCE. The DNA biosensor displays excellent sensing performance for detecting the relevant pathogenic DNA of APL with a detection limit of 83 pM (S/N = 3). Conclusion: According to the several experimental results, we believe that the simple and economical DNA biosensor has the potential to be an effective and powerful tool for detection of pathogenic genes in the clinical diagnosis.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , DNA/genética , Fusão Gênica/genética , Grafite/química , Nanocompostos/química , Proteínas de Fusão Oncogênica/genética , Técnicas Biossensoriais/instrumentação , Eletroquímica , Eletrodos , Humanos
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