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1.
Biosensors (Basel) ; 11(7)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34356695

RESUMO

The availability of antigen tests for SARS-CoV-2 represents a major step for the mass surveillance of the incidence of infection, especially regarding COVID-19 asymptomatic and/or early-stage patients. Recently, we reported the development of a Bioelectric Recognition Assay-based biosensor able to detect the SARS-CoV-2 S1 spike protein expressed on the surface of the virus in just three minutes, with high sensitivity and selectivity. The working principle was established by measuring the change of the electric potential of membrane-engineered mammalian cells bearing the human chimeric spike S1 antibody after attachment of the respective viral protein. In the present study, we applied the novel biosensor to patient-derived nasopharyngeal samples in a clinical set-up, with absolutely no sample pretreatment. More importantly, membrane-engineered cells were pre-immobilized in a proprietary biomatrix, thus enabling their long-term preservation prior to use as well as significantly increasing their ease-of-handle as test consumables. The plug-and-apply novel biosensor was able to detect the virus in positive samples with a 92.8% success rate compared to RT-PCR. No false negative results were recorded. These findings demonstrate the potential applicability of the biosensor for the early, routine mass screening of SARS-CoV-2 on a scale not yet realized.


Assuntos
Técnicas Biossensoriais/métodos , COVID-19/diagnóstico , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/análise , COVID-19/imunologia , Teste de Ácido Nucleico para COVID-19 , Teste Sorológico para COVID-19 , Linhagem Celular , Diagnóstico Precoce , Humanos , Limite de Detecção , Nasofaringe/imunologia , Nasofaringe/virologia , Vigilância da População , SARS-CoV-2/imunologia
2.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360949

RESUMO

In recent years, the increasing incidence and mortality of cancer have inspired the development of accurate and rapid early diagnosis methods in order to successfully cure cancer; however, conventional methods used for detecting tumor cells, including histopathological and immunological methods, often involve complex operation processes, high analytical costs, and high false positive rates, in addition to requiring experienced personnel. With the rapid emergence of sensing techniques, electrochemical cytosensors have attracted wide attention in the field of tumor cell detection because of their advantages, such as their high sensitivity, simple equipment, and low cost. These cytosensors are not only able to differentiate tumor cells from normal cells, but can also allow targeted protein detection of tumor cells. In this review, the research achievements of various electrochemical cytosensors for tumor cell detection reported in the past five years are reviewed, including the structures, detection ranges, and detection limits of the cytosensors. Certain trends and prospects related to the electrochemical cytosensors are also discussed.


Assuntos
Biomarcadores Tumorais/análise , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Animais , Humanos
3.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443351

RESUMO

For this study, we tested and optimized silicon surface functionalization procedures for capturing urinary extracellular vesicles (uEVs). The influence of the silane type (APTES or GOPS) and protein concentration on the efficiency of uEVs binding was investigated. Human lactadherin protein (LACT) was used to capture uEVs. We applied surface characterization techniques, including ellipsometry, atomic force microscopy, and time-of-flight secondary ion mass spectrometry, to observe changes in the biosensor surface after each functionalization step. uEVs were purified by a low-vacuum filtration method and concentrated by ultracentrifugation. The physical parameters of uEVs after the isolation procedure, such as morphology and size distribution, were determined using transmission electron microscopy and tunable resistive pulse sensing methods. We observed a gradual growth of the molecular layer after subsequent stages of modification of the silicon surface. The ToF-SIMS results showed no changes in the mean intensities for the characteristic peaks of amino acids and lipids in positive and negative polarization, in terms of the surface-modifying silane (APTES or GOPS) used. The most optimal concentration of LACT for the tested system was 25 µg/mL.


Assuntos
Técnicas Biossensoriais/métodos , Desenho de Fármacos , Vesículas Extracelulares/metabolismo , Humanos , Silanos/química , Silício/química , Propriedades de Superfície
4.
Nat Commun ; 12(1): 5031, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413312

RESUMO

The limited sensitivity of Förster Resonance Energy Transfer (FRET) biosensors hinders their broader applications. Here, we develop an approach integrating high-throughput FRET sorting and next-generation sequencing (FRET-Seq) to identify sensitive biosensors with varying substrate sequences from large-scale libraries directly in mammalian cells, utilizing the design of self-activating FRET (saFRET) biosensor. The resulting biosensors of Fyn and ZAP70 kinases exhibit enhanced performance and enable the dynamic imaging of T-cell activation mediated by T cell receptor (TCR) or chimeric antigen receptor (CAR), revealing a highly organized ZAP70 subcellular activity pattern upon TCR but not CAR engagement. The ZAP70 biosensor elucidates the role of immunoreceptor tyrosine-based activation motif (ITAM) in affecting ZAP70 activation to regulate CAR functions. A saFRET biosensor-based high-throughput drug screening (saFRET-HTDS) assay further enables the identification of an FDA-approved cancer drug, Sunitinib, that can be repurposed to inhibit ZAP70 activity and autoimmune-disease-related T-cell activation.


Assuntos
Técnicas Biossensoriais/métodos , Transferência Ressonante de Energia de Fluorescência/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Fosfotransferases/metabolismo , Células Cultivadas , Humanos , Engenharia de Proteínas/métodos , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Linfócitos T/metabolismo , Proteína-Tirosina Quinase ZAP-70/metabolismo
5.
Theranostics ; 11(16): 7767-7778, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335963

RESUMO

Background: Lipid droplets (LDs) establish a considerable number of contact sites with mitochondria to enable energy transfer and communication. In this study, we developed a fluorescent biosensor to image LD-mitochondria interactions at the nanoscale and further explored the function of LD-mediated matrix transmission in processes involving multi-organelle interactions. Methods: A fluorescent probe called C-Py (C21H19N3O2, 7-(diethylamino) coumarin-3-vinyl-4-pyridine acetonitrile) was designed and synthesized. Colocalization of C-Py and the commercial LD stain Nile Red was analyzed in HeLa cells. The fluorescence stability and signal to background ratio of C-Py under structured illumination microscopy (SIM) were compared to those of the commercial probe BODIPY493/503. The cytotoxicity of C-Py was assessed using CCK-8 assays. The uptake pattern of C-Py in HeLa cells was then observed under various temperatures, metabolic levels, and endocytosis levels. Contact sites between LDs and various organelles, such as mitochondria, nuclei, and cell membrane, were imaged and quantitated using SIM. Physical changes to the contact sites between LDs and mitochondria were monitored after lipopolysaccharide induction. Results: A LD-targeted fluorescent biosensor, C-Py, with good specificity, low background signal, excellent photostability, low cytotoxicity, and high cellular permeability was developed for tracking LD contact sites with multiple organelles using SIM. Using C-Py, the subcellular distribution and dynamic processes of LDs in living cells were observed under SIM. The formation of contact sites between LDs and multiple organelles was visualized at a resolution below ~200 nm. The number of LD-mitochondria contact sites formed was decreased by lipopolysaccharide treatment inducing an inflammatory environment. Conclusions: C-Py provides strategies for the design of ultra-highly selective biosensors and a new tool for investigating the role and regulation of LDs in living cells at the nanoscale.


Assuntos
Gotículas Lipídicas/metabolismo , Mitocôndrias/metabolismo , Imagem Individual de Molécula/métodos , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Células HeLa , Humanos , Metabolismo dos Lipídeos/fisiologia
6.
ACS Appl Mater Interfaces ; 13(34): 40342-40353, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34412466

RESUMO

Sensitive point-of-care methods for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in clinical specimens are urgently needed to achieve rapid screening of viral infection. We developed a magnetic quantum dot-based dual-mode lateral flow immunoassay (LFIA) biosensor for the high-sensitivity simultaneous detection of SARS-CoV-2 spike (S) and nucleocapsid protein (NP) antigens, which is beneficial for improving the detection accuracy and efficiency of SARS-CoV-2 infection in the point-of-care testing area. A high-performance magnetic quantum dot with a triple-QD shell (MagTQD) nanotag was first fabricated and integrated into the LFIA system to provide superior fluorescence signals, enrichment ability, and detectability for S/NP antigen testing. Two detection modes were provided by the proposed MagTQD-LFIA. The direct mode was used for rapid screening or urgent detection of suspected samples within 10 min, and the enrichment mode was used for the highly sensitive and quantitative analysis of SARS-CoV-2 antigens in biological samples without the interference of the "hook effect." The simultaneous detection of SARS-CoV-2 S/NP antigens was conducted in one LFIA strip, and the detection limits for two antigens under direct and enrichment modes were 1 and 0.5 pg/mL, respectively. The MagTQD-LFIA showed high accuracy, specificity, and stability in saliva and nasal swab samples and is an efficient tool with flexibility to meet the testing requirements for SARS-CoV-2 antigens in various situations.


Assuntos
Antígenos Virais/análise , Técnicas Biossensoriais/métodos , Proteínas do Nucleocapsídeo de Coronavírus/análise , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/análise , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Antígenos Virais/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Fluorescência , Corantes Fluorescentes/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Nanopartículas de Magnetita/química , Nasofaringe/virologia , Fosfoproteínas/análise , Fosfoproteínas/imunologia , Pontos Quânticos/química , Saliva/virologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
7.
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
8.
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
9.
Molecules ; 26(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34443603

RESUMO

Abnormal levels of reduced glutathione (GSH) and glutathione reductase (GR) are usually related to a variety of diseases, so it is of great significance to determine the GSH concentration and GR activity. We herein develop a smartphone-assisted colorimetric biosensor for the detection of GSH and GR activity in human serum and mouse liver using hemin/G-quadruplex DNAzyme. Firstly, an obvious color change from colorless to green can be observed, owing to the high peroxidase-like activity of hemin/G-quadruplex DNAzyme toward 2,2'-azino-bis(3-ethylbenzothiozoline-6-sulfonic acid) (ABTS). With the addition of GSH or GR, the H2O2-mediated oxidation of ABTS catalyzed by hemin/G-quadruplex DNAzyme is significantly inhibited, resulting in remarkable color fading. Therefore, the detection of GSH and GR activity can be achieved by observing the color transition or measuring the absorbance at 420 nm. The detection limit was estimated to be as low as 0.1 µM and 10 µU/mL for GSH and GR, respectively. More interestingly, the RGB values of the sensing system can be identified by the smartphone application (APP, color collect), which makes it an ideal format for on-site determination and point-of-care testing (POCT). In addition, the proposed method shows excellent selectivity and acceptable applicability for the determination of GSH concentration and GR activity in human serum samples and mouse liver tissues, which might hold great application potential in clinical diagnosis and drug screening.


Assuntos
Técnicas Biossensoriais/métodos , DNA Catalítico/metabolismo , Glutationa Redutase/sangue , Glutationa/sangue , Hemina/metabolismo , Fígado/metabolismo , Smartphone , Animais , Colorimetria , DNA Catalítico/química , Quadruplex G , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Humanos , Camundongos , Oxirredução
10.
Viruses ; 13(7)2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202815

RESUMO

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global health problem that the WHO declared a pandemic. COVID-19 has resulted in a worldwide lockdown and threatened to topple the global economy. The mortality of COVID-19 is comparatively low compared with previous SARS outbreaks, but the rate of spread of the disease and its morbidity is alarming. This virus can be transmitted human-to-human through droplets and close contact, and people of all ages are susceptible to this virus. With the advancements in nanotechnology, their remarkable properties, including their ability to amplify signal, can be used for the development of nanobiosensors and nanoimaging techniques that can be used for early-stage detection along with other diagnostic tools. Nano-based protection equipment and disinfecting agents can provide much-needed protection against SARS-CoV-2. Moreover, nanoparticles can serve as a carrier for antigens or as an adjuvant, thereby making way for the development of a new generation of vaccines. The present review elaborates the role of nanotechnology-based tactics used for the detection, diagnosis, protection, and treatment of COVID-19 caused by the SARS-CoV-2 virus.


Assuntos
Antivirais/uso terapêutico , COVID-19/diagnóstico , COVID-19/tratamento farmacológico , Nanotecnologia/métodos , Nanotecnologia/tendências , Técnicas Biossensoriais/métodos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Controle de Doenças Transmissíveis/métodos , Saúde Global , Humanos
11.
Viruses ; 13(6)2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199601

RESUMO

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is currently spreading and mutating with increasing speed worldwide. Therefore, there is an urgent need for a simple, sensitive, and high-throughput (HTP) assay to quantify virus-host interactions in order to quickly evaluate the infectious ability of mutant viruses and to develop or validate virus-inhibiting drugs. Here, we developed an ultrasensitive bioluminescent biosensor to evaluate virus-cell interactions by quantifying the interaction between the SARS-CoV-2 receptor binding domain (RBD) and its cellular receptor angiotensin-converting enzyme 2 (ACE2) both in living cells and in vitro. We have successfully used this novel biosensor to analyze SARS-CoV-2 RBD mutants and evaluated candidate small molecules (SMs), antibodies, and peptides that may block RBD:ACE2 interaction. This simple, rapid, and HTP biosensor tool will significantly expedite the detection of viral mutants and the anti-COVID-19 drug discovery process.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Técnicas Biossensoriais/métodos , Interações entre Hospedeiro e Microrganismos/fisiologia , Proteínas Luminescentes/metabolismo , SARS-CoV-2/metabolismo , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Células HEK293 , Ensaios de Triagem em Larga Escala/métodos , Humanos , Técnicas In Vitro , Ligação Proteica , Domínios Proteicos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
12.
Molecules ; 26(12)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205805

RESUMO

Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer system comprises a compact, low volume, temperature-controlled sensing chamber in three modules that can host any type of resistive gas sensor arrays. Furthermore, in this study three modular breath analyzers are explicitly tested for reproducibility in a real-life breath analysis experiment with several calibration transfer (CT) techniques using transfer samples from the experiment. The experiment consists of classifying breath samples from 15 subjects before and after eating a specific meal using three instruments. We investigate the possibility to transfer calibration models across instruments using transfer samples from the experiment under study, since representative samples of human breath at some conditions are difficult to simulate in a laboratory. For example, exhaled breath from subjects suffering from a disease for which the biomarkers are mostly unknown. Results show that many transfer samples of all the classes under study (in our case meal/no meal) are needed, although some CT methods present reasonably good results with only one class.


Assuntos
Técnicas Biossensoriais/métodos , Testes Respiratórios/métodos , Expiração/fisiologia , Sistema Respiratório/fisiopatologia , Adolescente , Biomarcadores/metabolismo , Calibragem , Humanos , Sistema Respiratório/metabolismo
13.
Molecules ; 26(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200473

RESUMO

The interactions of compounds with DNA have been studied since the recognition of the role of nucleic acid in organisms. The design of molecules which specifically interact with DNA sequences allows for the control of the gene expression. Determining the type and strength of such interaction is an indispensable element of pharmaceutical studies. Cognition of the therapeutic action mechanisms is particularly important for designing new drugs. Owing to their sensitivity, simplicity, and low costs, electrochemical methods are increasingly used for this type of research. Compared to other techniques, they require a small number of samples and are characterized by a high reliability. These methods can provide information about the type of interaction and the binding strength, as well as the damage caused by biologically active molecules targeting the cellular DNA. This review paper summarizes the various electrochemical approaches used for the study of the interactions between pharmaceuticals and DNA. The main focus is on the papers from the last decade, with particular attention on the voltammetric techniques. The most preferred experimental approaches, the electrode materials and the new methods of modification are presented. The data on the detection ranges, the binding modes and the binding constant values of pharmaceuticals are summarized. Both the importance of the presented research and the importance of future prospects are discussed.


Assuntos
DNA/química , Interações Medicamentosas/fisiologia , Técnicas Eletroquímicas/métodos , Preparações Farmacêuticas/química , Técnicas Biossensoriais/métodos , Dano ao DNA/efeitos dos fármacos , Eletrodos , Ácidos Nucleicos/química , Reprodutibilidade dos Testes
14.
J Mater Chem B ; 9(30): 5967-5981, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34254626

RESUMO

The infamous COVID-19 outbreak has left a crippling impact on the economy, healthcare infrastructure, and lives of the general working class, with all the scientists determined to find suitable and efficient diagnostic techniques and therapies to contain its ramifications. This article presents the complete outline of the diagnostic platforms developed using nanoparticles in the detection of SARS-CoV-2, delineating the direct and indirect use of nanomaterials in COVID-19 diagnosis. The properties of nanostructured materials and their relevance in the development of novel point-of-care diagnostic approaches for COVID-19 are highlighted. More importantly, the advantages of nanotechnologies over conventional reverse transcriptase-polymerase chain reaction technique and few other methods used in the detection of SARS-CoV-2 along with the viewpoints are discussed. Also, the future perspectives highlighting the commercial aspects of the nanotechnology-based diagnostic tools developed to combat the COVID-19 pandemic are presented.


Assuntos
COVID-19/diagnóstico , Nanoestruturas/química , Testes Imediatos , Anticorpos Antivirais/análise , Anticorpos Antivirais/química , Técnicas Biossensoriais/métodos , COVID-19/virologia , Colorimetria , Humanos , Técnicas de Amplificação de Ácido Nucleico , RNA Viral/análise , RNA Viral/química , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação
15.
Nat Commun ; 12(1): 4039, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193867

RESUMO

The controlled assembly of nanomaterials into desired architectures presents many opportunities; however, current preparations lack spatial precision and versatility in developing complex nano-architectures. Inspired by the amphiphilic nature of surfactants, we develop a facile approach to guide nanomaterial integration - spatial organization and distribution - in metal-organic frameworks (MOFs). Named surfactant tunable spatial architecture (STAR), the technology leverages the varied interactions of surfactants with nanoparticles and MOF constituents, respectively, to direct nanoparticle arrangement while molding the growing framework. By surfactant matching, the approach achieves not only tunable and precise integration of diverse nanomaterials in different MOF structures, but also fast and aqueous synthesis, in solution and on solid substrates. Employing the approach, we develop a dual-probe STAR that comprises peripheral working probes and central reference probes to achieve differential responsiveness to biomarkers. When applied for the direct profiling of clinical ascites, STAR reveals glycosylation signatures of extracellular vesicles and differentiates cancer patient prognosis.


Assuntos
Biomarcadores Tumorais/metabolismo , Técnicas Biossensoriais/métodos , Neoplasias Colorretais/diagnóstico , Vesículas Extracelulares/metabolismo , Estruturas Metalorgânicas/química , Nanoestruturas/química , Tensoativos/química , Ascite/metabolismo , Neoplasias Colorretais/metabolismo , Glicosilação , Humanos , Prognóstico
16.
Molecules ; 26(12)2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34203057

RESUMO

A biosensing membrane base on ferulic acid and glucose oxidase is synthesized onto a carbon paste electrode by electropolymerization via cyclic voltammetry in aqueous media at neutral pH at a single step. The developed biosensors exhibit a linear response from 0.082 to 34 mM glucose concentration, with a coefficient of determination R2 equal to 0.997. The biosensors display a sensitivity of 1.1 µAmM-1 cm-2, a detection limit of 0.025 mM, and 0.082 mM as glucose quantification limit. The studies reveal stable, repeatable, and reproducible biosensors response. The results indicate that the novel poly-ferulic acid membrane synthesized by electropolymerization is a promising method for glucose oxidase immobilization towards the development of glucose biosensors. The developed glucose biosensors exhibit a broader linear glucose response than other polymer-based glucose biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Ácidos Cumáricos/química , Técnicas Eletroquímicas/métodos , Glucose Oxidase/metabolismo , Glucose/análise , Polímeros/química , Técnicas Biossensoriais/normas , Eletrodos , Enzimas Imobilizadas , Glucose Oxidase/química , Limite de Detecção
17.
J Immunol ; 207(4): 1211-1221, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34312257

RESUMO

Long half-life of therapeutic Abs and Fc fusion proteins is crucial to their efficacy and is, in part, regulated by their interaction with neonatal Fc receptor (FcRn). However, the current methods (e.g., surface plasmon resonance and biolayer interferometry) for measurement of interaction between IgG and FcRn (IgG/FcRn) require either FcRn or IgG to be immobilized on the surface, which is known to introduce experimental artifacts and have led to conflicting data. To study IgG/FcRn interactions in solution, without a need for surface immobilization, we developed a novel (to our knowledge), solution-based homogeneous binding immunoassay based on NanoBiT luminescent protein complementation technology. We optimized the assay (NanoBiT FcRn assay) for human FcRn, mouse FcRn, rat FcRn, and cynomolgus FcRn and used them to determine the binding affinities of a panel of eight Abs. Assays could successfully capture the modulation in IgG/FcRn binding based on changes in Fc fragment of the Abs. We also looked at the individual contribution of Fc and F(ab)2 on the IgG/FcRn interaction and found that Fc is the main driver for the interaction at pH 6. Our work highlights the importance of using orthogonal methods to validate affinity data generated using biosensor platforms. Moreover, the simple add-and-read format of the NanoBiT FcRn assay is amenable for high-throughput screening during early Ab discovery phase.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Imunoensaio/métodos , Medições Luminescentes/métodos , Receptores Fc/imunologia , Sequência de Aminoácidos , Animais , Técnicas Biossensoriais/métodos , Humanos , Fragmentos Fc das Imunoglobulinas/imunologia , Testes Imunológicos/métodos , Camundongos , Ligação Proteica/imunologia , Ratos
18.
Methods Mol Biol ; 2350: 1-20, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34331275

RESUMO

Signal transduction processes are a necessary component of multicellular life, and their dysregulation is the basis for a host of syndromes and diseases. Thus, it is imperative that we discover the complex details of how signal transduction processes result in specific cellular outcomes. One of the primary mechanisms of regulation over signaling pathways is through spatiotemporal control. However, traditional methods are limited in their ability to reveal such details. To overcome these limitations, researchers have developed a variety of genetically encodable, fluorescent protein-based biosensors to study these dynamic processes in real time in living cells. Due to the complexities and interconnectedness of signaling pathways, it is thus desirable to use multiple biosensors in individual cells to better elucidate the relationships between signaling pathways. However, multiplexed imaging with such biosensors has been historically difficult. Nevertheless, recent developments in designs and multiplexing strategies have led to vast improvements in our capabilities. In this review, we provide perspectives on the recently developed biosensor designs and multiplexing strategies that are available for multiplexed imaging of signal transduction pathways.


Assuntos
Técnicas Biossensoriais/métodos , Imagem Molecular/métodos , Transdução de Sinais , Biomarcadores , Transferência Ressonante de Energia de Fluorescência/métodos , Espaço Intracelular/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência , Transporte Proteico , Espectrofotometria
19.
Methods Mol Biol ; 2350: 43-68, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34331278

RESUMO

Förster resonance energy transfer (FRET) biosensors are popular and useful for directly observing cellular signaling pathways in living cells. Until recently, multiplex imaging of genetically encoded FRET biosensors to simultaneously monitor several protein activities in one cell was limited due to a lack of spectrally compatible FRET pair of fluorescent proteins. With the recent development of miRFP series of near-infrared (NIR) fluorescent proteins, we are now able to extend the spectrum of FRET biosensors beyond blue-green-yellow into NIR. These new NIR FRET biosensors enable direct multiplex imaging together with commonly used cyan-yellow FRET biosensors. We describe herein a method to produce cell lines harboring two compatible FRET biosensors. We will then discuss how to directly multiplex-image these FRET biosensors in living cells. The approaches described herein are generally applicable to any combinations of genetically encoded, ratiometric FRET biosensors utilizing the cyan-yellow and NIR fluorescence.


Assuntos
Técnicas Biossensoriais/métodos , Imunofluorescência/métodos , Transdução de Sinais , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Proteínas de Transporte , Linhagem Celular , Ativação Enzimática , Transferência Ressonante de Energia de Fluorescência/métodos , Genes Reporter , Camundongos , Ligação Proteica , Proteínas rho de Ligação ao GTP/genética
20.
Molecules ; 26(13)2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34279424

RESUMO

Self-assembling peptides and carbon nanomaterials have attracted great interest for their respective potential to bring innovation in the biomedical field. Combination of these two types of building blocks is not trivial in light of their very different physico-chemical properties, yet great progress has been made over the years at the interface between these two research areas. This concise review will analyze the latest developments at the forefront of research that combines self-assembling peptides with carbon nanostructures for biological use. Applications span from tissue regeneration, to biosensing and imaging, and bioelectronics.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Diagnóstico por Imagem/métodos , Eletrônica , Nanoestruturas/química , Fragmentos de Peptídeos/química , Regeneração
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