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1.
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
2.
Molecules ; 26(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34443475

RESUMO

Different parts of a plant (seeds, fruits, flower, leaves, stem, and roots) contain numerous biologically active compounds called "phytoconstituents" that consist of phenolics, minerals, amino acids, and vitamins. The conventional techniques applied to extract these phytoconstituents have several drawbacks including poor performance, low yields, more solvent use, long processing time, and thermally degrading by-products. In contrast, modern and advanced extraction nonthermal technologies such as pulsed electric field (PEF) assist in easier and efficient identification, characterization, and analysis of bioactive ingredients. Other advantages of PEF include cost-efficacy, less time, and solvent consumption with improved yields. This review covers the applications of PEF to obtain bioactive components, essential oils, proteins, pectin, and other important materials from various parts of the plant. Numerous studies compiled in the current evaluation concluded PEF as the best solution to extract phytoconstituents used in the food and pharmaceutical industries. PEF-assisted extraction leads to a higher yield, utilizes less solvents and energy, and it saves a lot of time compared to traditional extraction methods. PEF extraction design should be safe and efficient enough to prevent the degradation of phytoconstituents and oils.


Assuntos
Fracionamento Químico/instrumentação , Fracionamento Químico/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Compostos Fitoquímicos , Indústria de Processamento de Alimentos , Solventes/química , Tecnologia Farmacêutica
3.
Molecules ; 26(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34299390

RESUMO

5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected to thermal or photochemical stresses. In addition, HMF deserves further consideration due to its potential toxic effects on human health. The processes at the origin of HMF formation in honey and in other foods, containing saccharides and proteins-mainly non-enzymatic browning reactions-can also produce other furanic compounds. Among others, 2-furaldehyde (2F) and 2-furoic acid (2FA) are the most abundant in honey, but also their isomers (i.e., 3-furaldehyde, 3F, and 3-furoic acid, 3FA) have been found in it, although in small quantities. A preliminary characterization of HMF, 2F, 2FA, 3F, and 3FA by cyclic voltammetry (CV) led to hypothesizing the possibility of a comprehensive quantitative determination of all these compounds using a simple and accurate square wave voltammetry (SWV) method. Therefore, a new parameter able to provide indications on quality of honey, named "Furanic Index" (FI), was proposed in this contribution, which is based on the simultaneous reduction of all analytes on an Hg electrode to ca. -1.50 V vs. Saturated Calomel Electrode (SCE). The proposed method, validated, and tested on 10 samples of honeys of different botanical origin and age, is fast and accurate, and, in the case of strawberry tree honey (Arbutus unedo), it highlighted the contribution to the FI of the homogentisic acid (HA), i.e., the chemical marker of the floral origin of this honey, which was quantitatively reduced in the working conditions. Excellent agreement between the SWV and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) data was observed in all samples considered.


Assuntos
Técnicas Eletroquímicas/métodos , Ericaceae/química , Furaldeído/análogos & derivados , Furanos/análise , Mel/análise , Furaldeído/análise
4.
Methods Mol Biol ; 2352: 201-226, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34324189

RESUMO

The detection of neurotransmitter release from reprogrammed human cell is an important demonstration of their functionality. Electrochemistry has the distinct advantages over alternative methods that it allows for the measuring of the analyte of interest at a high temporal resolution. This is necessary for fast events, such as neurotransmitter release and reuptake, which happen in the order of milliseconds to seconds. The precise description of these kinetic events can lead to insights into the function of cells in health and disease and allows for the exploration of events that might be missed using methods that look at absolute concentration values or methods that have a slower sampling rate. In the present chapter, we describe the use of constant potential amperometry and enzyme-coated multielectrode arrays for the detection of glutamate in vitro. These biosensors have the distinct advantage of "self-referencing," a method providing high selectivity while retaining outstanding temporal resolution. Here, we provide a step-by-step user guide for a commercially available system and its application for in vitro systems such as reprogrammed cells.


Assuntos
Reprogramação Celular , Técnicas Eletroquímicas , Neurotransmissores/biossíntese , Transmissão Sináptica , Técnicas de Cultura de Células , Reprogramação Celular/genética , Análise de Dados , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletroquímica/instrumentação , Eletroquímica/métodos , Software
5.
Chem Commun (Camb) ; 57(59): 7215-7231, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34223844

RESUMO

Heavy metal ions are one of the main sources of water pollution. Most heavy metal ions are carcinogens that pose a threat to both ecological balance and human health. With the increasing demand for heavy metal detection, electrochemical detection is favorable due to its high sensitivity and efficiency. Here, after discussing the pollution sources and toxicities of Hg(ii), Cd(ii), As(iii), Pb(ii), UO2(ii), Tl(i), Cr(vi), Ag(i), and Cu(ii), we review a variety of recent electrochemical methods for detecting heavy metal ions. Compared with traditional methods, electrochemical methods are portable, fast, and cost-effective, and they can be adapted to various on-site inspection sites. Our review shows that the electrochemical detection of heavy metal ions is a very promising strategy that has attracted widespread attention and can be applied in agriculture, life science, clinical diagnosis, and analysis.


Assuntos
Técnicas Eletroquímicas/métodos , Metais Pesados/análise , Poluentes Químicos da Água/análise , Cádmio/análise , DNA de Cadeia Simples , Eletrodos , Íons/química , Limite de Detecção , Mercúrio/análise , Nanotubos de Carbono/química
6.
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
7.
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
8.
Int J Mol Sci ; 22(14)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34298934

RESUMO

In this paper, the electrochemical behavior of two types of sensors based on modified screen-printed electrodes (one screen-printed electrode based on carbon (SPCE) and another screen-printed electrode modified with Prussian Blue (PB/SPCE)) was studied with the aim of sensitive detection of diosmin, an active pharmaceutical compound from the class of flavonoids. The scan electron microscopy technique was used for the morphological characterization of PB/SPCE. The preliminary analysis assessed the electrochemical behavior of SPCE and PB/SPCE in KCl solution and in a double solution of potassium ferrocyanide-potassium chloride. It was shown that the active area of PB/SPCE is superior to the one of SPCE, the greater sensitivity being related with the presence of the electroactive modifier. Similarly, in the case of diosmin detection, the PB/SPCE sensor detect more sensitivity the diosmin due to the electrocatalytic effect of PB. From the study of the influence of reaction rate on the sensor's electrochemical response, it was shown that the detection process is controlled by the adsorption process, the degree of surface coverage with electroactive molecules being higher in the case of PB/SPCE. From the PB/SPCE calibration curve, it wasdetermined that it has high sensitivity and low detection and quantification limit values (limit of detection 5.22 × 10-8 M). The applicability of the PB/SPCE sensor was confirmed by sensitive analysis of diosmin in pharmaceutical products. The voltammetric method is suitable for the detection and quantification of diosmin in pharmaceutical products. The method is simple, accurate, and quick and can be used in routine analysis in the examination of the quality of pharmaceutical products and other types of samples.


Assuntos
Diosmina/química , Preparações Farmacêuticas/química , Carbono/química , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção , Sensibilidade e Especificidade
9.
PLoS One ; 16(7): e0251342, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34197468

RESUMO

Amperial™ is a novel assay platform that uses immobilized antigen in a conducting polymer gel followed by detection via electrochemical measurement of oxidation-reduction reaction between H2O2/Tetrametylbenzidine and peroxidase enzyme in a completed assay complex. A highly specific and sensitive assay was developed to quantify levels of IgG antibodies to SARS-CoV-2 in saliva. After establishing linearity and limit of detection we established a reference range of 5 standard deviations above the mean. There were no false positives in 667 consecutive saliva samples obtained prior to 2019. Saliva was obtained from 34 patients who had recovered from documented COVID-19 or had documented positive serologies. All of the patients with symptoms severe enough to seek medical attention had positive antibody tests and 88% overall had positive results. We obtained blinded paired saliva and plasma samples from 14 individuals. The plasma was analyzed using an EUA-FDA cleared ELISA kit and the saliva was analyzed by our Amperial™ assay. All 5 samples with negative plasma titers were negative in saliva testing. Eight of the 9 positive plasma samples were positive in saliva and 1 had borderline results. A CLIA validation was performed as a laboratory developed test in a high complexity laboratory. A quantitative non-invasive saliva based SARS-CoV-2 antibody test was developed and validated with sufficient specificity to be useful for population-based monitoring and monitoring of individuals following vaccination.


Assuntos
Anticorpos Antivirais/imunologia , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Imunoglobulina G/imunologia , SARS-CoV-2/imunologia , Saliva/imunologia , Anticorpos Antivirais/análise , COVID-19/imunologia , COVID-19/virologia , Técnicas Eletroquímicas/métodos , Humanos , Imunoglobulina G/análise , Limite de Detecção , SARS-CoV-2/isolamento & purificação , Saliva/virologia
10.
J Mater Chem B ; 9(23): 4670-4677, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34060565

RESUMO

Enzyme-based electrochemical biosensors have been widely employed for analyte detection for several years. However, for wide application, there are many challenges to overcome, such as the sensitivity of the catalytic activity, and the reproducibility and stability of enzymes. In this work, an enzyme-free sensing strategy based on two-dimensional (2D) metal-organic frameworks (MOFs) as photosensitizers and singlet-oxygen (1O2) as the oxidant has been designed via photocatalysis and electrochemical analysis. To be specific, MOF sheets (Zn-ZnMOF) were prepared with Zn as the node and zinc(ii)tetraphenylporphyrin (TCPP(Zn)) as the ligand, which could generate 1O2 from air under light illumination, and sequentially the generated 1O2 could oxidize analytes to form their oxidation state which could be detected and reduced on the electrode, completing a redox cycle and amplifying electrochemical signals. Thanks to the morphology and superior quantum yield of 1O2 of the Zn-ZnMOF, this method could overcome the limitation of enzymes and afford selective detection, such as of hydroquinone with a detection limit of 0.8 µM in 0.1 M PBS (pH = 7.4). Furthermore, the method does not require additional reactive reagents but only with air and on/off light switching. Thirdly, the method detects the target without washing and enzyme-labelled. With these merits, this work provides a new platform for MOFs as photosensitizers for electrochemical sensors and further development of sensitive, selective, and stable electroanalytical devices for bio-application.


Assuntos
Técnicas Eletroquímicas/métodos , Estruturas Metalorgânicas/química , Oxigênio Singlete/química , Técnicas Biossensoriais/métodos
11.
Food Chem ; 362: 130219, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34091170

RESUMO

The use of artificial colorants in food is highly regulated due to their potential to harm human health. Thus, it is crucial to detect these substances effectively to ensure conformance with industrial standards. In this work, we prepared a photomultiplier tube (PMT)-based electrochemiluminescence (ECL) sensor and a charged coupled device (CCD)-based ECL sensor and compared their merits in the detection of sunset yellow (SY) dye. The sensors used C,N quantum dot-embedded g-C3N4 nanosheets (QDs@NSs) as the ECL agent and K2S2O8 as the coreactant. SY was analyzed on the basis of amplification in the QDs@NHs-K2S2O8 ECL system. The PMT-based sensor realized ultrasensitive detection using a single electrode, especially at low concentrations of SY. A CCD-based sensor imaged the ECL phenomenon of an electrode array and provided the advantages of high throughput and time savings. Under optimized conditions, both sensors exhibited high specificity, reproducibility and stability; detection limits of 20 nM with PMT detection and 5 µM with CCD detection were determined for SY, with detection ranging over at least two decades. The practical feasibilities of these systems were confirmed by satisfactory detection of SY in real drink samples.


Assuntos
Compostos Azo/análise , Bebidas Gaseificadas/análise , Técnicas Eletroquímicas/instrumentação , Corantes de Alimentos/análise , Compostos Azo/química , Técnicas Eletroquímicas/métodos , Eletrodos , Corantes de Alimentos/química , Limite de Detecção , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Nanoestruturas , Pontos Quânticos , Reprodutibilidade dos Testes
12.
Molecules ; 26(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34071841

RESUMO

Food safety and quality control pose serious issues to food industry and public health domains, in general, with direct effects on consumers. Any physical, chemical, or biological unexpected or unidentified food constituent may exhibit harmful effects on people and animals from mild to severe reactions. According to the World Health Organization (WHO), unsafe foodstuffs are especially dangerous for infants, young children, elderly, and chronic patients. It is imperative to continuously develop new technologies to detect foodborne pathogens and contaminants in order to aid the strengthening of healthcare and economic systems. In recent years, peptide-based sensors gained much attention in the field of food research as an alternative to immuno-, apta-, or DNA-based sensors. This review presents an overview of the electrochemical biosensors using peptides as molecular bio-recognition elements published mainly in the last decade, highlighting their possible application for rapid, non-destructive, and in situ analysis of food samples. Comparison with peptide-based optical and piezoelectrical sensors in terms of analytical performance is presented. Methods of foodstuffs pretreatment are also discussed.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Inocuidade dos Alimentos , Animais , DNA , Impedância Elétrica , Escherichia coli/metabolismo , Humanos , Listeria monocytogenes/efeitos dos fármacos , Microfluídica , Conformação Molecular , Oxirredução , Peptídeos/química , Potenciometria , Controle de Qualidade
13.
ACS Appl Mater Interfaces ; 13(24): 28610-28626, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34110776

RESUMO

The development of aggregation-induced emission enhancement (AIEE) active nanoprobes without any synthetic complication for solution-state and organic thin-film transistor (OTFT)-based sensory applications is still a challenging task. In this study, the novel pyrene-incorporated Schiff base (5-phenyl-4-((pyren-1-ylmethylene)amino)-4H-1,2,4-triazole-3-thiol; PT2) with an AIEE property was synthesized via a one-pot reaction and was reported for detecting Zn2+ and tyrosine in the solution state and OTFT. In the AIEE studies of PT2 (in CH3CN) at various water fractions (fw: 0-97.5%), the existence of J-aggregation, crystalline changes, and nanofibers formation was confirmed by ultraviolet absorption/photoluminescence (UV/PL) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic-light scattering (DLS) techniques. Similarly, PT2-based Zn2+ detection and sensory reversibility with tyrosine were demonstrated by UV/PL studies with evidence related to crystalline/nanolevel changes in PXRD, SEM, TEM, AFM, and DLS data. Distinct decay profiles associated with the AIEE and sensory responses of PT2 were observed in time-resolved photoluminescence spectra. From the standard deviation and linear fittings of PL titrations, detection limits (LODs) of the Zn2+ with PT2 and the tyrosine with PT2-Zn2+ were estimated as 0.79 and 45 nM, respectively. High-resolution mass and 1H NMR results confirmed 2:1 and 1:1 stoichiometry and binding sites of PT2-Zn2+-PT2* and tyrosine-Zn2+ complexes. Moreover, the values of association constants determined by linear fittings were 4.205 × 10-7 and 1.73 × 10-8 M-2, correspondingly. Optimization via the density functional theory disclosed the binding sites and suppression of twisted intramolecular charge transfer/photoinduced electron transfer (TICT/PET) as well as the involvement of restricted intramolecular rotation in the AIEE and PET "ON-OFF-ON" mechanisms in the Zn2+ and tyrosine sensors. Results from the B16-F10 cellular and zebrafish imaging of AIEE, Zn2+, and tyrosine sensors further attested the applicability of PT2 in biological samples. Finally, the PT2 and pentacene-incorporated OTFT devices were fabricated. The devices displayed more than 90% change in drain-source current when reacted with Zn2+ with an LOD of 5.46 µM but showed no response to tyrosine, thereby confirming the reversibility. Moreover, the OTFT devices also demonstrated Zn2+ ion detection in tap water and lake water samples.


Assuntos
Corantes Fluorescentes/química , Pirenos/química , Tirosina/análise , Zinco/análise , Animais , Teoria da Densidade Funcional , Água Potável/análise , Técnicas Eletroquímicas/métodos , Corantes Fluorescentes/síntese química , Lagos/análise , Limite de Detecção , Modelos Químicos , Pirenos/síntese química , Bases de Schiff/síntese química , Bases de Schiff/química , Transistores Eletrônicos , Peixe-Zebra
14.
ACS Appl Mater Interfaces ; 13(24): 27868-27879, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34110781

RESUMO

We demonstrate that a novel functionalized interface, where molecularly imprinted polymer nanoparticles (nanoMIPs) are attached to screen-printed graphite electrodes (SPEs), can be utilized for the thermal detection of the cardiac biomarker troponin I (cTnI). The ultrasensitive detection of the unique protein cTnI can be utilized for the early diagnosis of myocardial infraction (i.e., heart attacks), resulting in considerably lower patient mortality and morbidity. Our developed platform presents an innovative route to develop accurate, low-cost, and disposable sensors for the diagnosis of cardiovascular diseases, specifically myocardial infraction. A reproducible and advantageous solid-phase approach was utilized to synthesize high-affinity nanoMIPs (average size = 71 nm) for cTnI, which served as synthetic receptors in a thermal sensing platform. To assess the performance and commercial potential of the sensor platform, various approaches were used to immobilize nanoMIPs onto thermocouples or SPEs: dip coating, drop casting, and a covalent approach relying on electrografting with an organic coupling reaction. Characterization of the nanoMIP-functionalized surfaces was performed with electrochemical impedance spectroscopy, atomic force microscopy, and scanning electron microscopy. Measurements from an in-house designed thermal setup revealed that covalent functionalization of nanoMIPs onto SPEs led to the most reproducible sensing capabilities. The proof of application was provided by measuring buffered solutions spiked with cTnI, which demonstrated that through monitoring changes in heat transfer at the solid-liquid interface, we can measure concentrations as low as 10 pg L-1, resulting in the most sensitive test of this type. Furthermore, preliminary data are presented for a prototype platform, which can detect cTnI with shorter measurement times and smaller sample volumes. The excellent sensor performance, versatility of the nanoMIPs, and reproducible and low-cost nature of the SPEs demonstrate that this sensor platform technology has a clear commercial route with high potential to contribute to sustainable healthcare.


Assuntos
Polímeros Molecularmente Impressos/química , Nanopartículas/química , Troponina I/análise , Biomarcadores/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Grafite/química , Temperatura
15.
ACS Appl Mater Interfaces ; 13(24): 28538-28545, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34121402

RESUMO

A 3D printed flexible tactile sensor with graphene-polydimethylsiloxane (PDMS) microspheres for microstructure perception is presented. The structure of the tactile sensor is inspired by the texture of the human finger and is designed to enable the detection of various levels of surface roughness via the processing of tactile signals. The tactile sensor with a unique graphene-PDMS microsphere structure shows excellent comprehensive mechanical properties, including a robust stretching ability (elongation at break of the sensing layer is 70%), excellent sensing ability (short response time of 60 ms), high sensitivity (sensitivity up to 2.4 kPa-1), and cycle stability (over 2000 loading cycles). In addition, such versatility and sensitivity allow the electronic skin not only to accurately monitor pressure but also to distinguish various surface topographies with microscale differences, and to detect the action of an air fluid.


Assuntos
Dimetilpolisiloxanos/química , Grafite/química , Microesferas , Dispositivos Eletrônicos Vestíveis , Biomimética/métodos , Técnicas Eletroquímicas/métodos , Humanos , Impressão Tridimensional , Pele/química , Aço Inoxidável/química , Propriedades de Superfície
16.
ACS Appl Mater Interfaces ; 13(25): 29293-29302, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34128651

RESUMO

Biological recognition sites are very useful for biomedical purposes and, more specifically, for polymeric scaffolds. However, synthetic polymers are not capable of providing specific biological recognition sites. To solve this inconvenience, functionalization of biological moieties is typically performed, oftentimes via peptide binding. In this sense, the main task is capturing the biological complexity of a protein. This study proposes a possible alternative solution to this challenge. Our approach is based on the combination of molecular imprinting (MI) and electrospinning processes. We propose here an alternative MI approach with polymeric structures, instead of using cross-linkers and monomers as conventionally performed. Different PCL-protein scaffolds were produced via electrospinning before performing MI. Gelatin, collagen, and elastin were used as proteins. Results evidenced that the MI process conducted with PCL electrospun membranes was carried out with ionic interactions between the desired molecules and the recognition sites formed. In addition, it has been proved that MI was more efficient when using gelatin as a template. This approach opens a new stage in the development of recognition sites in scaffolds obtained with synthetic polymers and their application for biomedical purposes.


Assuntos
Técnicas Eletroquímicas/métodos , Impressão Molecular/métodos , Poliésteres/química , Proteínas/química , Gelatina/química , Nanofibras/química
17.
Nat Biomed Eng ; 5(7): 678-689, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34183802

RESUMO

Assays for cancer diagnosis via the analysis of biomarkers on circulating extracellular vesicles (EVs) typically have lengthy sample workups, limited throughput or insufficient sensitivity, or do not use clinically validated biomarkers. Here we report the development and performance of a 96-well assay that integrates the enrichment of EVs by antibody-coated magnetic beads and the electrochemical detection, in less than one hour of total assay time, of EV-bound proteins after enzymatic amplification. By using the assay with a combination of antibodies for clinically relevant tumour biomarkers (EGFR, EpCAM, CD24 and GPA33) of colorectal cancer (CRC), we classified plasma samples from 102 patients with CRC and 40 non-CRC controls with accuracies of more than 96%, prospectively assessed a cohort of 90 patients, for whom the burden of tumour EVs was predictive of five-year disease-free survival, and longitudinally analysed plasma from 11 patients, for whom the EV burden declined after surgery and increased on relapse. Rapid assays for the detection of combinations of tumour biomarkers in plasma EVs may aid cancer detection and patient monitoring.


Assuntos
Neoplasias Colorretais/diagnóstico , Técnicas Eletroquímicas/métodos , Vesículas Extracelulares/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Área Sob a Curva , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Intervalo Livre de Doença , Molécula de Adesão da Célula Epitelial/sangue , Molécula de Adesão da Célula Epitelial/metabolismo , Vesículas Extracelulares/imunologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Recidiva , Adulto Jovem
18.
J Phys Chem Lett ; 12(23): 5443-5447, 2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34081461

RESUMO

Enzymes encapsulated in metal-organic frameworks (enzyme@MOFs), as a promising immobilized enzyme, were investigated for intrinsic catalytic activities at the single entity level via a stochastic collision electrochemical technique. Zeolitic imidazolate frameworks with amorphous (aZIF-8) and crystalline (ZIF-8) structures were chosen as model MOFs to encapsulate glucose oxidase (GOx). We carried out single enzyme@MOF nanoparticle (NP) collision experiments using the carbon ultramicroelectrode (CUME), which demonstrated that the catalytic activity of GOx@ZIF-8 NPs was much less than GOx@aZIF-8 NPs. Meanwhile, the kcat and TON per GOx in aZIF-8 NPs were obtained, revealing the intrinsic catalytic activity of GOx in aZIF-8 NPs at the single entity level. This strategy is the first approach for investigating enzyme@MOFs at a single entity level, which can not only broaden the horizons of single entity electrochemistry (SEE) but also provide further insights into research on electrochemistry, catalysis, and nanocomposites.


Assuntos
Técnicas Eletroquímicas/métodos , Enzimas Imobilizadas/química , Estruturas Metalorgânicas/química , Nanocompostos/química , Nanopartículas/química , Catálise , Técnicas Eletroquímicas/instrumentação , Enzimas Imobilizadas/análise , Estruturas Metalorgânicas/análise , Nanocompostos/análise , Nanopartículas/análise , Processos Estocásticos
19.
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
20.
Anal Bioanal Chem ; 413(16): 4217-4226, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33934192

RESUMO

Tetrabromobisphenol A (TBBPA) is a kind of brominated flame retardant that is usually added to products to reduce their flame retardancy. However, its extensive use has resulted in their residues being found in the environment, which is very harmful. Herein, an indirect competitive immunosensor has been established for TBBPA detection based on the signal amplification system. Pd nanospheres in situ reduced on the surface of MnO2 nanosheet hybrid (MnO2/Pd) was used as the label for the secondary antibody through the Pd-N bond, and gold-toluidine blue composite was loaded onto MWCNTs (MWCNTs/Au-TB), which functioned as the platform for the immunosensor. The spherical structure of Pd had abundant catalytic active sites, which enhanced the catalytic activity of MnO2/Pd as the label, hence amplifying the signal response. Besides, MWCNTs/Au-TB improved electron transfer and produced a strong signaling pathway for immobilizing antigens through the Au-NH2 bond, which can specifically recognize primary antibodies to improve sensitivity. The immunosensor had a linear concentration range of 0-81 ng/mL, a low detection limit of 0.17 ng/mL (S/N = 3), with good stability, selectivity, and reproducibility based on the above advantages. Additionally, the acceptable accuracy and recoveries (recoveries, 92-124%; CV, 3.3-8.8%) in the real water sample analysis indicated that this strategy is promising for emerging pollutant analysis.


Assuntos
Cetrimônio/química , Técnicas Eletroquímicas/métodos , Compostos de Manganês/química , Óxidos/química , Bifenil Polibromatos/análise , Poluentes Químicos da Água/análise , Anticorpos Imobilizados/química , Técnicas Biossensoriais/métodos , Imunoensaio/métodos , Limite de Detecção , Nanoestruturas/química
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