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1.
ACS Appl Mater Interfaces ; 14(8): 10844-10855, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35172574

RESUMO

The widespread and long-lasting effect of the COVID-19 pandemic has called attention to the significance of technological advances in the rapid diagnosis of SARS-CoV-2 virus. This study reports the use of a highly stable buffer-based zinc oxide/reduced graphene oxide (bbZnO/rGO) nanocomposite coated on carbon screen-printed electrodes for electrochemical immuno-biosensing of SARS-CoV-2 nuelocapsid (N-) protein antigens in spiked and clinical samples. The incorporation of a salt-based (ionic) matrix for uniform dispersion of the nanomixture eliminates multistep nanomaterial synthesis on the surface of the electrode and enables a stable single-step sensor nanocoating. The immuno-biosensor provides a limit of detection of 21 fg/mL over a linear range of 1-10 000 pg/mL and exhibits a sensitivity of 32.07 ohms·mL/pg·mm2 for detection of N-protein in spiked samples. The N-protein biosensor is successful in discriminating positive and negative clinical samples within 15 min, demonstrating its proof of concept used as a COVID-19 rapid antigen test.


Assuntos
Antígenos Virais/análise , COVID-19/diagnóstico , Proteínas do Nucleocapsídeo de Coronavírus/análise , Grafite/química , Nanocompostos/química , Óxido de Zinco/química , Anticorpos Imobilizados/imunologia , Antígenos Virais/imunologia , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Limite de Detecção , Fosfoproteínas/análise , Fosfoproteínas/imunologia , Estudo de Prova de Conceito , SARS-CoV-2/química
2.
ACS Appl Mater Interfaces ; 14(5): 6417-6427, 2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35089707

RESUMO

A novel double-resonant plasmonic substrate for fluorescence amplification in a chip-based apta-immunoassay is herein reported. The amplification mechanism relies on plasmon-enhanced fluorescence (PEF) effect. The substrate consists of an assembly of plasmon-coupled and plasmon-uncoupled gold nanoparticles (AuNPs) immobilized onto a glass slide. Plasmon-coupled AuNPs are hexagonally arranged along branch patterns whose resonance lies in the red band (∼675 nm). Plasmon-uncoupled AuNPs are sprinkled onto the substrate, and they exhibit a narrow resonance at 524 nm. Numerical simulations of the plasmonic response of the substrate through the finite-difference time-domain (FDTD) method reveal the presence of electromagnetic hot spots mainly confined in the interparticle junctions. In order to realize a PEF-based device for potential multiplexing applications, the plasmon resonances are coupled with the emission peak of 5-carboxyfluorescein (5-FAM) fluorophore and with the excitation/emission peaks of cyanine 5 (Cy5). The substrate is implemented in a malaria apta-immunoassay to detect Plasmodium falciparum lactate dehydrogenase (PfLDH) in human whole blood. Antibodies against Plasmodium biomarkers constitute the capture layer, whereas fluorescently labeled aptamers recognizing PfLDH are adopted as the top layer. The fluorescence emitted by 5-FAM and Cy5 fluorophores are linearly correlated (logarithm scale) to the PfLDH concentration over five decades. The limits of detection are 50 pM (1.6 ng/mL) with the 5-FAM probe and 260 fM (8.6 pg./mL) with the Cy5 probe. No sample preconcentration and complex pretreatments are required. Average fluorescence amplifications of 160 and 4500 are measured in the 5-FAM and Cy5 channel, respectively. These results are reasonably consistent with those worked out by FDTD simulations. The implementation of the proposed approach in multiwell-plate-based bioassays would lead to either signal redundancy (two dyes for a single analyte) or to a simultaneous detection of two analytes by different dyes, the latter being a key step toward high-throughput analysis.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Carbocianinas/química , Fluoresceínas/química , Vidro/química , Humanos , Imunoensaio/métodos , L-Lactato Desidrogenase/sangue , L-Lactato Desidrogenase/imunologia , Limite de Detecção , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/sangue , Proteínas de Protozoários/imunologia , Propriedades de Superfície
3.
J Mater Chem B ; 10(3): 450-455, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34981801

RESUMO

The simple and sensitive detection of protein is of great significance in biological research and medical diagnosis. However, the commonly-used methods, such as enzyme-linked immunosorbent assay (ELISA), usually rely on signal tags labeled on the antibody, which limits the sensitivity and stability. Herein, we have designed and constructed a colorimetric immunosensor in this work for the analysis of protein by taking advantage of 2D metal-organic framework (2D-MOF) nanomaterials as enzyme mimics. The nanomaterial shows a strong peroxidase mimetic activity, and good selectivity after it is modified with a specific aptamer. Therefore, taking carcinoembryonic antigen (CEA) as an example, this immunosensor achieves a good detection performance with a linear range from 1 pg mL-1 to 1000 ng mL-1 and a limit of detection (LOD) of 0.742 pg mL-1. Moreover, the sensor can successfully distinguish the human serum of colorectal cancer patients from healthy people, which suggests that this sensor has great potential in clinical applications. More importantly, the mass production, low cost, stability and ease of transport of the MOFs nanomaterials, as well as the ability for visual detection will make this sensor suitable for point-of-care (POC) testing in remote or resource-poor areas.


Assuntos
Antígeno Carcinoembrionário/sangue , Colorimetria/métodos , Imunoensaio/métodos , Estruturas Metalorgânicas/química , Nanoestruturas/química , Anticorpos Imobilizados/imunologia , Aptâmeros de Nucleotídeos/química , Benzidinas/química , Biomarcadores/sangue , Antígeno Carcinoembrionário/imunologia , Catálise , Compostos Cromogênicos/química , Neoplasias Colorretais/sangue , Humanos , Ácidos Nucleicos Imobilizados/química , Limite de Detecção
4.
ACS Appl Mater Interfaces ; 14(1): 41-48, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34932313

RESUMO

Zika virus (ZIKV) infection is associated with the Guillain-Barré syndrome, and when non-vector congenital transmission occurs, fetal brain abnormalities are expected. After ZIKV infection, the blood, breast milk, and other body fluids contain low viral loads. Their detection is challenging as it requires the processing of larger input volumes of the clinical samples. Pre-enrichment is a valuable strategy to increase the analyte concentration. Therefore, the authors propose the use of a hierarchal composite polyaniline-(electrospun nanofiber) hydrogel mat (ENM) for the simultaneous enrichment and impedimetric sensing of ZIKV viral particles. The electrospinning conditions of polyvinyl alcohol and alginate, including blend formulation, were optimized through a factorial design. Disintegration and gelatinization were controlled via cross-linking to improve the hydrogel properties. Hierarchization was achieved by in situ chemical deposition of conductive polyaniline. The carboxyl groups of the ENM were used for the covalent immobilization of anti-ZIKV polyclonal antibodies used in the specific recognition of ZIKV within the medium of Vero cell culture. The specific capture and desorption of virions were studied at different pHs. ENMs were characterized by scanning electron microscopy and FTIR. Atomic force microscopy along with UV-vis and electrochemical impedance spectroscopies was used to monitor the antibody immobilization, ZIKV capture, and elution processes. Our results show that 14.2 mg (0.25 cm3) of ENM can capture 38.7 ± 2.5 µg of ZIKV with a desorption rate of 99.97% (38.29 ± 2.7 µg ZIKV), which is reusable for at least three times. Therefore, the capture capacity (micrograms of ZIKV captured per milligram of ENM) of polyaniline-hierarchized mats was 2.72 µg ZIKV/mg. The impedance LOD value was determined to be 2.76 µg of ZIKV particles (approximately 6.6 × 103 PFU/mL). As a result, we present a fast small-scale purification system that can simultaneously monitor ZIKV electrochemically and optically.


Assuntos
Alginatos/química , Compostos de Anilina/química , Técnicas Biossensoriais/métodos , Nanofibras/química , Carga Viral/métodos , Zika virus/isolamento & purificação , Animais , Anticorpos Imobilizados/imunologia , Anticorpos Antivirais/imunologia , Sangue/virologia , Chlorocebus aethiops , Técnicas Eletroquímicas , Hidrogéis/química , Imunoensaio/métodos , Limite de Detecção , Células Vero , Zika virus/imunologia
5.
Mikrochim Acta ; 189(1): 17, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873664

RESUMO

As well known, the electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)32+) heavily relies on highly positive or negative triggered voltage, prejudicing the detection toward the bio-molecules. In this work, Ru(bpy)32+ could generate enhanced and stable ECL at a low potential of 0.05 V (vs. Ag/AgCl) on graphene-PtPd hybrid, attributing to its excellent electrocatalysis from the synergistic effect between Pt and Pd. The obtained low-potential-driven ECL could be quenched by MoS2 nanoflowers. Based on the quenching effect, a sandwich "signal-off" ECL immunosensor was fabricated to sensitively detect carcinoembryonic antigen (CEA). A linear calibration curve from 1 fg mL-1 to 1 ng mL-1 was obtained along with a low detection limit of 0.54 fg mL-1 (S/N = 3) under optimal conditions. The sensor showed satisfactory specificity, stability, and reproducibility and was successfully applied to determine CEA in actual samples. The recoveries ranged from 98.80 to 100.23%, and the relative standard deviation (RSD) was lower than 5%. Above all, this work explored new materials in low-potential-driven ECL system and provided a reliable sensing strategy for clinical applications.


Assuntos
Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Substâncias Luminescentes/química , Nanocompostos/química , Compostos Organometálicos/química , Anticorpos Imobilizados/imunologia , Antígeno Carcinoembrionário/imunologia , Dissulfetos/química , Grafite/química , Humanos , Limite de Detecção , Molibdênio/química , Paládio/química , Platina/química , Reprodutibilidade dos Testes
6.
Mikrochim Acta ; 189(1): 5, 2021 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-34855013

RESUMO

An ultrasensitive label-free electrochemical immunosensor was fabricated for quantitative detection of Lactobacillus rhamnosus GG (LGG). The N/O co-doped three-dimensional hierarchical porous graphitic (THPG) carbon was synthesized by a one-step synthesis of polyaniline hydrogel, and followed by simple carbonization and chemical activation procedures. Because of the unique structure design, the obtained THPG carbon networks possess an ultra-large specific surface area of 4859 m2 g-1 along with a class of highly graphitic carbons. The results offer an enormous surface area and excellent electrical conductivity for label-free electrochemical immunosensing of probiotic L. rhamnosus strain. Under optimal conditions, the immunosensor showed a good linear relationship between peak current and concentration of LGG (R2 = 0.9976), with a detection limit of 2 CFU mL-1. Furthermore, this label-free immunosensor also shows good specificity, long-term stability, and reliability, and could be applied to detect probiotic LGG in dairy products and drinks with satisfactory results. The present protocol was shown to be quite promising for practical screening and functional evaluation of probiotic products containing LGG. A ultrasensitive label-free electrochemical immunosensor based on THPG carbon was fabricated for detection of Lactobacillus rhamnosus GG.


Assuntos
Carga Bacteriana/métodos , Grafite/química , Imunoensaio/métodos , Lactobacillus rhamnosus/isolamento & purificação , Probióticos/análise , Anticorpos Imobilizados/imunologia , Laticínios/análise , Laticínios/microbiologia , Técnicas Eletroquímicas , Lactobacillus rhamnosus/imunologia , Limite de Detecção , Nitrogênio/química , Oxigênio/química , Reprodutibilidade dos Testes
7.
Mikrochim Acta ; 189(1): 32, 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34932168

RESUMO

The design of a sandwich-type SERS immunoassay (surface-enhanced Raman spectroscopy) is demonstrated operating in dual surface enhancement and dual-tag paradigm. The capture and detection antibodies are linked to two SERS-active substrates and form together the three-dimensional (3D) structure after specific binding to interleukin 6. A variety of metal combinations is tested (Au-Ag, Au-Au, and Ag-Ag), but an enhanced electromagnetic field is generated only due to coupling of Ag and Au nanoparticles with an Au hexagonal nanoarray. The amplified in that way Raman signals improve the limit of detection over 3 times in comparison to the assay with only one SERS-active substrate. It is also shown that the proper readout of the true-positive signal can be achieved in assays with two Raman tags, and this approach also improves LOD. For the optimal combination of the metal-metal junction and Raman tags, a linear relationship between the Raman signal and the concentration of IL-6 is obtained in the range 0-1000 pg⋅mL-1with LOD of 25.2 pg mL-1and RSD < 10%. The presented proof-of-concept of the SERS immunoassay with the dual-enhancement and dual-tag opens additional opportunities for engineering reliable SERS biosensing.


Assuntos
Imunoensaio/métodos , Interleucina-6/análise , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Anticorpos Imobilizados/imunologia , Ouro/química , Humanos , Interleucina-6/imunologia , Limite de Detecção , Prata/química , Trombina/análise , Trombina/imunologia
8.
Mikrochim Acta ; 189(1): 38, 2021 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-34958417

RESUMO

A sensitive detection of carbohydrate antigen 15-3 (CA15-3) levels may allow for early diagnosis and monitoring the treatment of breast cancer, but this can only be made in routine clinical practice if low-cost immunosensors are available. In this work, we developed a sandwich-type electrochemical immunosensor capable of rapid detection of CA15-3 with an ultra-low limit of detection (LOD) of 0.08 fg mL-1 within a wide linear concentration range from 0.1 fg mL-1 to 1 µg mL-1. The immunosensor had a matrix of a layer-by-layer film of Au nanoparticles and reduced graphene oxide (Au-rGO) co-electrodeposited on screen-printed carbon electrodes (SPCE). The high sensitivity was achieved by using secondary antibodies (Ab2) labeled with horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2) as signal amplifiers, and hydroquinone (HQ) was used as an electron mediator. The immunosensor was selective for CA15-3 in human serum and artificial saliva samples, robust, and stable to permit storage at 4 °C for more than 30 days. With its high performance, the immunosensor may be incorporated into future point-of-care (POC) devices to determine CA15-3 in distinct biological fluids, including in blood and saliva samples.


Assuntos
Biomarcadores Tumorais/sangue , Técnicas Eletroquímicas/métodos , Grafite/química , Imunoensaio/métodos , Nanopartículas Metálicas/química , Mucina-1/sangue , Anticorpos Imobilizados/imunologia , Armoracia/enzimologia , Biomarcadores Tumorais/imunologia , Ouro/química , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Hidroquinonas/química , Limite de Detecção , Mucina-1/imunologia , Reprodutibilidade dos Testes , Saliva/química
9.
Mikrochim Acta ; 188(11): 403, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34731317

RESUMO

Polyaniline (PANI) was functionalized by thiol-ene click chemistry to obtain carboxylic acid-tethered polyaniline (PCOOH). The versatility of PCOOH as an immobilization matrix was demonstrated by constructing four different biosensors for detection of metabolites and cancer biomarker. Immobilization efficiency of PCOOH was investigated by surface plasmon resonance and fluorescence microscopic analysis which revealed dense immobilization of biomolecules on PCOOH as compared to conventional PANI. A sandwich electrochemical biosensor was constructed using PCOOH for detection of liver cancer biomarker, α-fetoprotein (AFP). The sensor displayed sensitivity of 15.24 µA (ng mL-1)-1 cm-2, with good specificity, reproducibility (RSD 3.4%), wide linear range (0.25-40 ng mL-1) at - 0.1 V (vs. Ag/AgCl), and a low detection limit of 2 pg mL-1. The sensor was validated by estimating AFP in human blood serum samples where the AFP concentrations obtained are consistent with the values estimated using ELISA. Furthermore, utilization of PCOOH for construction of enzymatic biosensor was demonstrated by covalent immobilization of glucose oxidase, uricase, and horseradish peroxidase (HRP) for detection of glucose, uric acid, and H2O2, respectively. The biosensors displayed reasonable sensitivity (50, 148, 127 µA mM-1 cm-2), and linear ranges (0.1-5, 0.1-6, 0.1-7 mM) with a detection limit of 10, 1, and 8 µM for glucose, uric acid, and H2O2, respectively. The present study demonstrates the capability of PCOOH to support and enable oxidation of H2O2 generated by oxidase enzymes as well as HRP enzyme catalyzed reduction of H2O2. Thus, PCOOH offers a great promise as an immobilization matrix for development of high-performance biosensors to quantify a variety of other disease biomarkers. Carboxylic acid-tethered polyaniline synthesized by thiol-ene click chemistry was used as matrix to construct four different electrochemical biosensors for detection of cancer biomarker α-fetoprotein, glucose, uric acid, and H2O2.


Assuntos
Compostos de Anilina/química , Técnicas Biossensoriais/métodos , Ácidos Carboxílicos/química , Anticorpos Imobilizados/imunologia , Armoracia/enzimologia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/imunologia , Técnicas Eletroquímicas/métodos , Enzimas Imobilizadas/química , Glucose/análise , Glucose Oxidase/química , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Reprodutibilidade dos Testes , Urato Oxidase/química , Ácido Úrico/análise , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/imunologia
10.
Mikrochim Acta ; 188(11): 402, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34731326

RESUMO

Synthetic cannabinoids are one of the many substances of abuse widely spreading in modern society. Medical practitioners and law enforcement alike highly seek portable, efficient, and reliable tools for on-site detection and diagnostics. Here, we propose a colorimetric lateral flow assay (LFA) combined with dye-loaded polymersome to detect the synthetic cannabinoid JWH-073 efficiently. Rhodamine B-loaded polymersome was conjugated to antibodies and fully characterized. Two LFA were proposed (sandwich and competitive), showing a high level of sensitivity with a limit of detection (LOD) reaching 0.53 and 0.31 ng/mL, respectively. The competitive assay was further analyzed by fluorescence, where the LOD reached 0.16 ng/mL. The application of the LFA over spiked synthetic saliva or real human saliva demonstrated an overall response of 94% for the sandwich assay and 97% for the competitive LFA. The selectivity of the system was assessed in the presence of various interferents. The analytical performance of the LFA system showed a coefficient of variation below 6%. The current LFA system appears as a plausible system for non-invasive detection of substance abuse and shows promise for synthetic cannabinoid on-site sensing.


Assuntos
Canabinoides/análise , Corantes Fluorescentes/química , Poliésteres/química , Polietilenoglicóis/química , Rodaminas/química , Detecção do Abuso de Substâncias/métodos , Anticorpos Imobilizados/imunologia , Canabinoides/imunologia , Colorimetria/instrumentação , Colorimetria/métodos , Humanos , Drogas Ilícitas/análise , Drogas Ilícitas/imunologia , Imunoensaio/instrumentação , Imunoensaio/métodos , Indóis/análise , Indóis/imunologia , Limite de Detecção , Naftalenos/análise , Naftalenos/imunologia , Papel , Reprodutibilidade dos Testes , Saliva/química , Detecção do Abuso de Substâncias/instrumentação
11.
J Mater Chem B ; 9(44): 9153-9161, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34694310

RESUMO

Imidacloprid is the most widely used insecticide in agriculture and its intensive use over the last 30 years has caused a global concern due to its potentially toxic effects on the ecosystem. Considering the recent scientific interest in novel simple methods for imidacloprid analysis, we propose a label-free sensitive and specific localised surface plasmon resonance system for the detection of the insecticide based on 2D nanostructured metasurfaces with highly performing plasmonic properties. The specificity of the sensor proposed was achieved by covalent bio-functionalization of the metasurface using a smart and easy one-step procedure mediated by carbon disulphide. The biosensor produced was tested using a set of imidacloprid standard solutions showing a competitive limit of detection, lower than 1 ng mL-1. Our novel nanosensing configuration represents a valid and reliable solution to realize low-cost portable POC tests as an alternative to the laborious and expensive methods traditionally used for insecticide detection.


Assuntos
Inseticidas/análise , Neonicotinoides/análise , Nitrocompostos/análise , Ressonância de Plasmônio de Superfície/métodos , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Ouro/química , Inseticidas/imunologia , Limite de Detecção , Nanopartículas Metálicas/química , Neonicotinoides/imunologia , Nitrocompostos/imunologia
12.
Angew Chem Int Ed Engl ; 60(52): 26947-26953, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34647402

RESUMO

Analytical tests/devices that are used outside laboratory settings are required to have a very simple analytical protocol to get clearance by regulatory authorities. This study describes sink/float magnetic immunoassays, a new type of rapid, mix-and-observe, instrument-free tests for the detection of biomarkers in untreated biological samples that are very simple and might meet the simple-to-use criterion of authorities to be used in the field. These tests can tell whether an analyte is above or below a predetermined level within 25-45 minutes based on the sinking or floating of a mm-sized sphere on the surface of which an immunoassay that uses reporter antibodies conjugated to superparamagnetic nanoparticles is performed. This manuscript describes the theory and proof-of-concept applications of sink/float magnetic immunoassays for the detection of C-Reactive Protein, anti-Treponema pallidum antibodies and E. coli bacteria.


Assuntos
Imunoensaio/métodos , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Anticorpos Imobilizados/imunologia , Proteína C-Reativa/análise , Proteína C-Reativa/imunologia , Escherichia coli/isolamento & purificação , Humanos , Nanopartículas Magnéticas de Óxido de Ferro/química , Fenômenos Magnéticos , Estudo de Prova de Conceito , Coelhos , Treponema pallidum/imunologia
13.
Mikrochim Acta ; 188(10): 334, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34498145

RESUMO

An innovative sensing assay is described for point-of-care (PoC) quantification of a biomarker of Alzheimer's disease, amyloid ß-42 (Aß-42). This device is based on a cellulose paper-dye test strip platform in which the corresponding detection layer is integrated by applying a molecularly imprinted polymer (MIP) to the cellulose paper surface. Briefly, the cellulose paper is chemically modified with a silane to subsequently apply the MIP detection layer. The imprinting process is confirmed by the parallel preparation of a control material, namely a non-imprinted polymer (NIP). The chemical changes of the surface were evaluated by Fourier transform infrared spectroscopy (FTIR), contact angle, and thermogravimetric analysis (TG). Proteins and peptides can be quantified by conventional staining methods. For this purpose, Coomassie blue (CB) was used as a staining dye for the detection and quantification of Aß-42. Quantitative determination is made possible by taking a photograph and applying an appropriate mathematical treatment to the color coordinates provided by the ImageJ program. The MIP shows a linear range between 1.0 ng/mL and 10 µg/mL and a detection limit of 0.71 ng/mL. Overall, this cellulose-based assay is suitable for the detection of peptides or proteins in a sample by visual comparison of color change. The test strip provides a simple, instrument-free, and cost-effective method with high chemical stability, capable of detecting very small amounts of peptides or proteins in a sample, and can be used for the detection of any (bio)molecule of interest.


Assuntos
Peptídeos beta-Amiloides/sangue , Celulose/química , Colorimetria/métodos , Imunoensaio/métodos , Fragmentos de Peptídeos/sangue , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/imunologia , Animais , Anticorpos Imobilizados/imunologia , Biomarcadores/sangue , Bovinos , Colorimetria/instrumentação , Corantes/química , Imunoensaio/instrumentação , Limite de Detecção , Polímeros Molecularmente Impressos/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Testes Imediatos , Corantes de Rosanilina/química
14.
ACS Appl Mater Interfaces ; 13(39): 46225-46232, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34553591

RESUMO

To date, two-dimensional (2D) and three-dimensional (3D) metal organic frameworks (MOFs) have been promising materials for applications in electrocatalysis, separation, and sensing. However, the exploration of a simple method for simultaneous fabrication of 2D/3D MOFs on a surface remains challenging. Herein, a one-step and in situ electrosynthesis strategy for fabrication of 2D Hemin-bridged MOF sheets (Hemin-MOFs) or 2D/3D Zn(II)-MOF hybrid nanocomposites on an electrode is reported. It exhibits varied morphologies at different electrodeposition times and attains a 2D/3D complex morphology by adding 1,3,5-benzenetricarboxylic acid (H3BTC) as an organic ligand. The morphology and size of 2D Hemin-MOFs are important factors that influence their performance. Since Pt nanoparticles (PtNPs) are grown on 2D Hemin-MOF sheets, this composite can serve as the peroxidase mimics and PtNPs can act as an anchor to capture the antibody. Therefore, this hybrid nanosheet-modified electrode is used as an electrochemical sensing platform for ultrasensitive pig immunoglobulin G (IgG) and the surface-protective antigen (Spa) protein of Erysipelothrix rhusiopathiae immunodetection. Moreover, this work provides a new avenue for the electrochemical synthesis of 2D/3D MOF hybrid nanocomposites with a high surface area and biomimetic catalysts.


Assuntos
Antígenos de Bactérias/análise , Imunoensaio/métodos , Imunoglobulina G/análise , Estruturas Metalorgânicas/química , Nanocompostos/química , Animais , Anticorpos Imobilizados/imunologia , Antígenos de Bactérias/imunologia , Catálise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Erysipelothrix/química , Hemina/química , Imunoensaio/instrumentação , Imunoglobulina G/imunologia , Limite de Detecção , Nanopartículas Metálicas/química , Oxirredução , Oxigênio/química , Platina/química , Suínos , Ácidos Tricarboxílicos/química , Zinco/química
15.
ACS Appl Mater Interfaces ; 13(39): 46440-46450, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34547887

RESUMO

Pressure-based immunoassays have been studied for point-of-care testing for which increasing the sensitivity is still a challenge. In this study, we described an enhanced pressure-based immunoassay with a versatile electronic sensor for the sensitive biological analysis. The versatile electronic sensor had multifunctional sensing capabilities with temperature and pressure recording. Magnetic bead-modified capture antibody and platinum nanoparticle-labeled detection antibody were used as the biorecognition element of the target carcinoembryonic antigen (CEA) (as a model analyte) and would form a sandwich-type immune complex with CEA. After simple magnetic separation, this complex was transferred into the detection chamber, which contained both hydrogen peroxide (H2O2) and 3,3',5,5'-tetramethylbenzidine (TMB). With the catalytic ability of PtNPs, the "H2O2-TMB-PtNPs" system was catalyzed to generate a large amount of oxygen (O2) and photothermal agent of oxidizer TMB (ox-TMB). Meanwhile, in a sealed chamber, further irradiation with an 808 nm near-infrared laser led to a triple-step signal amplification strategy of pressure increase, temperature increase, and gas thermal expansion to receive a strong electrical signal through the electronic sensor in real time. Thus, the amplified electrical signal from the electronic sensor could reveal the target concentration. In addition, we also verified that the synergistic system with two physical quantities had a lower limit of detection and a wider detection range compared to the detection system with a single physical quantity. In general, this immunoassay not only helped in exploring an effective signal amplification pathway but also offered an opportunity for the development of versatile electronic sensors in point-of-care settings.


Assuntos
Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Pressão , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Benzidinas/química , Antígeno Carcinoembrionário/imunologia , Compostos Cromogênicos/química , Técnicas Eletroquímicas/instrumentação , Grafite/química , Humanos , Peróxido de Hidrogênio/química , Imunoensaio/instrumentação , Limite de Detecção , Nanopartículas Metálicas/química , Platina/química , Estudo de Prova de Conceito , Temperatura
16.
Mikrochim Acta ; 188(10): 329, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34495394

RESUMO

A highly sensitive electrochemical biosensors has been developed for the detection of multiplex micro ribonucleic acids (miRNAs) by modifying an electrode with reduced graphene oxide/poly(2-aminobenzylamine)/gold nanoparticles and adopting porous, hollow silver-gold nanoparticles as tagged labeling with metal ions. In addition, an anti-deoxyribonucleic acid (DNA)-RNA hybrid [S9.6] antibody was used to detect different hybridized capture DNAs and miRNAs that can detect multiple miRNAs simultaneously. The developed electrochemical platform exhibits high selectivity, stability, and sensitivity with a wide linear range from 1 fM to 10 nM and a low detection limit of 0.98 fM, 3.58 fM, and 0.25 fM for miRNA-155, miRNA-21, and miRNA-16, respectively. In addition, the proposed electrochemical biosensor capable for the simultaneous detection of miRNA-155, miRNA-16, and miRNA-21, which are breast cancer biomarkers, in normal human serum, can be adopted and potentially used for breast cancer screening.


Assuntos
Biomarcadores Tumorais/sangue , Técnicas Biossensoriais/métodos , Neoplasias da Mama/diagnóstico , Técnicas Eletroquímicas/métodos , MicroRNAs/sangue , Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/imunologia , Neoplasias da Mama/sangue , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , MicroRNAs/imunologia , Poliaminas/química , Porosidade , Prata/química
17.
Bioelectrochemistry ; 142: 107934, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34474206

RESUMO

A novel competitive-type electrochemical immunosensor based on square wave voltammetry (SWV) response was developed for the quantitative detection of 1-Aminohydantoin (AHD). To improve the conductivity of this immunosensor nanocomposites with good electrical conductivity were prepared as a signal amplification platform for the immunosensor by growing Au nanoparticles on the surface of Ce-based metal-organic framework (Ce-MOF). In addition, methylene blue (MB)-loaded Au@Pt and coating antigen (OVA-AHD) connected as a signal label. When the target was introduced, it competed with the coating antigen for the Ab, which led to a reduction in the number of signal probes bound to the Ab. The concentration of AHD can be determined by SWV detection of the MB signal loaded on the signal labels. Under optimal conditions, the wide linear range of 0.001-1000 µg /L and a low detection limit of 1.35 × 10-7 µg/L were achieved. Ultimately, the developed method displayed excellent specificity in practical applications, providing a promising probability to detect nitrofuran metabolites residues to guarantee food safety.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Estruturas Metalorgânicas/imunologia , Nitrofuranos/análise , Anticorpos Imobilizados/imunologia , Nanopartículas Metálicas/química
18.
ACS Appl Mater Interfaces ; 13(36): 43715-43725, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34469103

RESUMO

An inverted pyramidal metasurface was designed, fabricated, and studied at the nanoscale level for the development of a label-free pathogen detection on a chip platform that merges nanotechnology and surface-enhanced Raman scattering (SERS). Based on the integration and synergy of these ingredients, a virus immunoassay was proposed as a relevant proof of concept for very sensitive detection of hepatitis A virus, for the first time to our best knowledge, in a very small volume (2 µL), without complex signal amplification, allowing to detect a minimal virus concentration of 13 pg/mL. The proposed work aims to develop a high-flux and high-accuracy surface-enhanced Raman spectroscopy (SERS) nanobiosensor for the detection of pathogens to provide an effective method for early and easy water monitoring, which can be fast and convenient.


Assuntos
Técnicas Biossensoriais/métodos , Vírus da Hepatite A/isolamento & purificação , Nanoporos , Análise Espectral Raman/métodos , Anticorpos Imobilizados/imunologia , Anticorpos Antivirais/imunologia , Técnicas Biossensoriais/instrumentação , Ouro/química , Vírus da Hepatite A/imunologia , Imunoensaio/instrumentação , Imunoensaio/métodos , Estudo de Prova de Conceito , Análise Espectral Raman/instrumentação , Microbiologia da Água
19.
Mikrochim Acta ; 188(10): 317, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34476602

RESUMO

Human epidermal growth factor receptor 2 (HER2) is one of the key molecular targets in breast cancer pathogenesis. Overexpression and/or amplification of HER2 in approximately 15-20% of breast cancer patients is associated with high mortality and poor prognosis. Accumulating evidence shows that accurate and sensitive detection of HER2 improves the survival outcomes for HER2-positive breast cancer patients from targeted therapies. The current methods of clinical determination of HER2 expression levels are based on slide-based assays that rely on invasively collected primary tumours. Alternatively, ELISA-based detection of the shredded HER2 extracellular domain (HER2-ECD) of has been suggested as a surrogate method for monitoring disease progress and treatment response in breast cancer patients. In the past decade, biosensors have emerged as an alternative modality for the detection of circulating HER2-ECD in human serum samples. In particular, electrochemical biosensors based on nanomaterials and antibodies and aptamers have been increasingly developed as promising tools for rapid, sensitive, and cost-effective detection of HER2-ECD. These biosensors harness the high affinity and specificity of antibodies and aptamers, and unique conductive properties, biocompatibility, large surface area, and chemical stability of nanomaterials for selective and sensitive assessment of the HER2. This review provides an overview of the recent advances in the application of nanomaterials-based immunosensors and aptasensors for detection of circulating HER2-ECD. In particular, various electrochemical techniques, detection approaches, and nanomaterials are discussed. Further, analytical figures of merit of various HER2 immunosensors and aptasensors are compared. Finally, possible challenges and potential opportunities for biosensor-based detection of HER2-ECD are discussed.


Assuntos
Biomarcadores Tumorais/sangue , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Nanopartículas Metálicas/química , Receptor ErbB-2/sangue , Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/química , Biomarcadores Tumorais/imunologia , Neoplasias da Mama/sangue , Neoplasias da Mama/diagnóstico , Humanos , Proteínas Imobilizadas/química , Metais Pesados/química , Nanocompostos/química , Domínios Proteicos , Receptor ErbB-2/química , Receptor ErbB-2/imunologia
20.
ACS Appl Mater Interfaces ; 13(36): 42513-42521, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34473477

RESUMO

We present an approach to improve the detection sensitivity of a streaming current-based biosensor for membrane protein profiling of small extracellular vesicles (sEVs). The experimental approach, supported by theoretical investigation, exploits electrostatic charge contrast between the sensor surface and target analytes to enhance the detection sensitivity. We first demonstrate the feasibility of the approach using different chemical functionalization schemes to modulate the zeta potential of the sensor surface in a range -16.0 to -32.8 mV. Thereafter, we examine the sensitivity of the sensor surface across this range of zeta potential to determine the optimal functionalization scheme. The limit of detection (LOD) varied by 2 orders of magnitude across this range, reaching a value of 4.9 × 106 particles/mL for the best performing surface for CD9. We then used the optimized surface to profile CD9, EGFR, and PD-L1 surface proteins of sEVs derived from non-small cell lung cancer (NSCLC) cell-line H1975, before and after treatment with EGFR tyrosine kinase inhibitors, as well as sEVs derived from pleural effusion fluid of NSCLC adenocarcinoma patients. Our results show the feasibility to monitor CD9, EGFR, and PD-L1 expression on the sEV surface, illustrating a good prospect of the method for clinical application.


Assuntos
Técnicas Biossensoriais/métodos , Vesículas Extracelulares/química , Eletricidade Estática , Anticorpos Imobilizados/imunologia , Antígeno B7-H1/análise , Antígeno B7-H1/metabolismo , Linhagem Celular Tumoral , Técnicas Eletroquímicas , Receptores ErbB/análise , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Vesículas Extracelulares/efeitos dos fármacos , Vesículas Extracelulares/imunologia , Humanos , Limite de Detecção , Inibidores de Proteínas Quinases/farmacologia , Tetraspanina 29/análise , Tetraspanina 29/metabolismo
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