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1.
Food Chem ; 300: 125176, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351258

RESUMO

Mycotoxins are toxic metabolites produced by fungi or molds, which may cause serious harm to human health through polluted cereal foods. In order to measure the typical mycotoxin contaminations in wheat and corn, a surface plasmon resonance (SPR) method was established using SPR sensor chip that was fabricated based on self-assembled monolayer. The minimum detection limit of aflatoxin B1, ochratoxin A, zearalenone and deoxynivalenol were identified as 0.59 ng/mL, 1.27 ng/mL, 7.07 ng/mL and 3.26 ng/mL, respectively. The cross-reactivity for all four mycotoxins were demonstrated to be low. Moreover, the test data were compared with HPLC-MS/MS confirmatory analysis results and good agreement was found between them. In conclusion, the SPR method for simultaneously detecting four mycotoxins has been developed with high sensitivity, good linearity and specificity, which can meet the detection requirements of cereal foods.


Assuntos
Micotoxinas/análise , Ressonância de Plasmônio de Superfície/métodos , Triticum/química , Zea mays/química , Aflatoxina B1/análise , Aflatoxina B1/imunologia , Cromatografia Líquida de Alta Pressão , Reações Cruzadas , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Hidrazonas/química , Limite de Detecção , Micotoxinas/imunologia , Ocratoxinas/análise , Ocratoxinas/imunologia , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície/instrumentação , Espectrometria de Massas em Tandem , Tricotecenos/análise , Tricotecenos/imunologia , Triticum/microbiologia , Zea mays/microbiologia , Zearalenona/análise , Zearalenona/imunologia
2.
Int J Nanomedicine ; 14: 4833-4847, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308661

RESUMO

Background: The use of functionalized graphene oxide (fGO) has led to a new trend in the sensor field, owing to its high sensitivity with regards to sensing characteristics and easy synthesis procedures. Methods: In this study, we developed an ultra-sensitive carboxyl-graphene oxide (carboxyl-GO)-based surface plasmon resonance (SPR) aptasensor using peptides to detect human chorionic gonadotropin (hCG) in clinical serum samples. The carboxyl-GO based SPR aptasensor provided high affinity and stronger binding of peptides, which are great importance to allow for a non-immunological label-free mechanism. Also, it allows the detection of low concentrations of hCG, which are in turn considered to be important clinical parameters to diagnose ectopic pregnancies and paraneoplastic syndromes. Results: The high selectivity of the carboxyl-GO-based SPR aptasensor for hCG recombinant protein was verified by the addition of the interfering proteins bovine serum albumin (BSA) and human serum albumin (HSA), which did not affect the sensitivity of the sensor. The carboxyl-GO-based chip can enhance the assay efficacy of interactions between peptides and had a high affinity binding for a ka of 17×106 M-1S-1. The limit of detection for hCG in clinical serum samples was 1.15 pg/mL. Conclusion: The results of this study demonstrated that the carboxyl-GO-based SPR aptasensor had excellent sensitivity, affinity and selectivity, and thus the potential to be used as disease-related biomarker assay to allow for an early diagnosis, and possibly a new area in the field of biochemical sensing technology.


Assuntos
Técnicas Biossensoriais/instrumentação , Gonadotropina Coriônica/sangue , Grafite/química , Ressonância de Plasmônio de Superfície/instrumentação , Animais , Bovinos , Eletroquímica , Humanos , Peptídeos/química , Espectroscopia Fotoeletrônica , Soroalbumina Bovina/química
3.
Opt Express ; 27(11): 15996-16011, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31163787

RESUMO

In this paper, the dynamics of the spontaneous emission rate of Rhodamine 6G dye molecules, coupled into disorder-induced optical cavities in a scattering medium, is investigated by a time-resolved spectroscopic technique. The system is a wedge-type wave-guiding system formed by a polymer with randomly positioned air inclusions. The scattering of light in the medium induces transverse Anderson localization, which gives rise to quasi-optical modes or Anderson-localized cavities. The presence of these modes strongly enhances the decay emission of the emitters. The waveguide is fabricated by a conventional fiber drawing technique inside a fused silica micro-rod. Localized optical modes are observed to appear in the form of sharp spectral resonance peaks at various frequencies throughout the photoluminescence spectrum of the dye molecules. The spontaneous emission rate of the molecules on resonance with the localized modes is measured to enhance by a factor of up to 6.8, which elucidates that the transverse Anderson localization enables an efficient way to alter the spontaneous emission rate of quantum emitters in an optically asymmetric simple wedge-type photonic waveguide, offering a moderate alternative to highly engineered sophisticated light-wave devices.


Assuntos
Corantes Fluorescentes/química , Aumento da Imagem/métodos , Rodaminas/química , Espalhamento de Radiação , Ressonância de Plasmônio de Superfície/instrumentação
4.
Appl Opt ; 58(11): 2839-2844, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-31044886

RESUMO

In this study we report the development of a novel viral pathogen immunosensor technology based on the electrochemical modulation of the optical signal from a surface plasmon wave interacting with a redox dye reporter. The device is formed by incorporating a sandwich immunoassay onto the surface of a plasmonic device mounted in a micro-electrochemical flow cell, where it is functionalized with a monoclonal antibody aimed to a specific target pathogen antigen. Once the target antigen is bound to the surface, it promotes the capturing of a secondary polyclonal antibody that has been conjugated with a redox-active methylene blue dye. The methylene blue displays a reversible change in the complex refractive index throughout a reduction-oxidation transition, which generates an optical signal that can be electrochemically modulated and detected at high sensitivity. For proof-of-principle measurements, we have targeted the hemagglutinin protein from the H5N1 avian influenza A virus to demonstrate the capabilities of our device for detection and quantification of a critical influenza antigen. Our experimental results of the EC-SPR-based immunosensor under potential modulation showed a 300 pM limit of detection for the H5N1 antigen.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos Virais/análise , Imunoensaio/instrumentação , Virus da Influenza A Subtipo H5N1/imunologia , Azul de Metileno/química , Ressonância de Plasmônio de Superfície/instrumentação , Técnicas Biossensoriais/instrumentação , Limite de Detecção
5.
Opt Express ; 27(8): 11348-11360, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31052980

RESUMO

The fiber geometry, fiber parameters and mode-guiding properties are crucial for realizing high-performance fiber-based sensors. In this work, we propose and demonstrate a few-mode fiber (FMF)-based surface plasmon resonance (SPR) biosensor. The FMF-SPR sensor was fabricated via side-polishing a few-mode fiber and coating a thin layer of gold film, on the basis of the optimization of fiber geometry, thickness of the gold film and mode selection, which were performed with the finite element method. The refractive index (RI) sensing performance of three such sensors with different residual fiber thicknesses were investigated. In the RI range from 1.333 to 1.404, the highest sensitivity up to 4903 nm/RIU and a figure of merit of 46.1 RIU-1 are achieved. For testing the bovine serum albumin (BSA) solution, an averaged BSA RI sensitivity of 6328 nm/RIU and an averaged BSA concentration sensitivity of 1.17 nm/(mg/ml) are realized. Benefiting from only a few modes supported in the FMF, a smaller line-width of the SPR spectrum is obtained, which further results in a higher figure of merit (FOM). Moreover, when combined with the superiority of the mode-multiplexing technology brought by the FMF, the FMF-SPR sensors may find applications in biochemical analysis with high performance and high throughputs.


Assuntos
Técnicas Biossensoriais/instrumentação , Tecnologia de Fibra Óptica/métodos , Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Refratometria , Ressonância de Plasmônio de Superfície/métodos
6.
Biosens Bioelectron ; 134: 90-96, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30959393

RESUMO

Mercury is a diversely bioaccumulating heavy metal pollutant toxic to all life forms. In this work, an optical biosensor has been developed and calibrated for universal detection and quantification of mercuric ions, in the range 0.1-540 parts per billion, in biological and environmental samples. Chitosan capped gold nanoparticles on bovine serum albumin are proposed as an ultrasensitive plasmonic mercury receptor on U-bend optical fiber platform. The sensor was calibrated and tested with tap water, sewage contaminated water, marine water, long lived sea fish tissue, fossil fuel fly ash contaminated soil and vegetable samples. The sensor performance was validated with real samples inherently containing mercury. Overall standard error of less than 15% and a coefficient of variation less than 12% (n = 3) was found across all samples, indicating good fitness for diverse usage. Experimentally determined limit of detection of mercuric ions was 0.1 parts per billion in tap water (twenty times lesser than the Environment protection agency limit of 2 parts per billion in drinking water) and 0.2 parts per billion in sea fish and vegetable samples with negligible cross sensitivity towards other metal ions.


Assuntos
Quitosana/química , Contaminação de Alimentos/análise , Ouro/química , Mercúrio/análise , Soroalbumina Bovina/química , Poluentes do Solo/análise , Ressonância de Plasmônio de Superfície/instrumentação , Poluentes Químicos da Água/análise , Animais , Bovinos , Água Potável/análise , Desenho de Equipamento , Análise de Alimentos/instrumentação , Proteínas Imobilizadas/química , Limite de Detecção , Nanopartículas/química , Alimentos Marinhos/análise , Solo/química , Verduras/química
7.
Biosens Bioelectron ; 135: 102-110, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004920

RESUMO

We present a plasmonic biosensor capable of detecting the presence of bisphenol A in ultra-low concentrations, yielding a wavelength shift of 0.15 ±â€¯0.01 nm in response to a solution of 1 fM concentration with limit of detection of 330 ±â€¯70 aM The biosensing device consists of an array of gold nano-antennae with a total length of 2.3 cm that generate coupled localised surface plasmons (cLSPs) and is covalently modified with an aptamer specific for bisphenol A recognition. The array of nano-antennae is fabricated on a lapped section of standard telecommunication optical fibre, allowing for potential multiplexing and its use in remote sensing applications. These results have been achieved without the use of enhancement techniques and therefore the approach allows the direct detection of bisphenol A, a low molecular weight (228 Da) target usually detectable only by indirect detection strategies. Its detection at such levels is a significant step forward in measuring small molecules at ultra-low concentrations. Furthermore, this new sensing platform paves the way for the development of portable systems for in-situ agricultural measurements capable of retrieving data on a substance of very high concern at ultra-low concentrations.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos Benzidrílicos/análise , Fenóis/análise , Ressonância de Plasmônio de Superfície/instrumentação , Poluentes Químicos da Água/análise , Desenho de Equipamento , Ouro/química , Limite de Detecção , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Fibras Ópticas
8.
Biosens Bioelectron ; 135: 216-223, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31026776

RESUMO

Fibrinogen, which is a glycoprotein that circulates in the blood, plays various important biological roles, e.g., in blood coagulation, fibroblast proliferation, angiogenesis, and wound healing. Abnormal levels of fibrinogen in plasma have been identified as a key biomarker of a variety of disorders from cardiovascular diseases to hemophilia. Therefore, the development of a quantitative assay for fibrinogen in the blood has emerged as an important issue for the prevention and diagnosis of these diseases. Meanwhile, it is well known that erythrocytes can selectively capture fibrinogen because of the fibrinogen receptor expressed on their plasma membrane. Inspired by these biological interactions, herein, we devised an erythrocyte membrane (EM)-blanketed biosensor based on localized surface plasmon resonance (LSPR) for highly sensitive detection of fibrinogen. By placing the EM onto a nanoparticle-on-substrate, we enhanced the LSPR signal, achieving highly sensitive and selective detection of fibrinogen. We demonstrated that fibrinogen detection is possible over a wide concentration range, 0.001-5.000 mg/mL, which can cover normal and pathological blood fibrinogen levels. In addition, it was verified that the biosensor selectively detects fibrinogen in comparison with other human-blood-plasma components. The nanoplasmonic sensor blanketed with the EM opens up new opportunities for the development of a robust fibrinogen-sensing technology.


Assuntos
Membrana Eritrocítica/química , Fibrinogênio/análise , Ressonância de Plasmônio de Superfície/métodos , Desenho de Equipamento , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Ressonância de Plasmônio de Superfície/instrumentação
9.
Biosens Bioelectron ; 132: 368-374, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30901726

RESUMO

A simple, convenient, and inexpensive method to fabricate optical fiber based biosensors which utilize periodic hole arrays in gold films for signal transduction is reported. The process of hole array formation mainly relies on self-assembly of hydrogel microgels in combination with chemical gold film deposition and subsequent transfer of the perforated film onto an optical fiber tip. In the fabrication process solely chemical wet lab techniques are used, avoiding cost-intensive instrumentation or clean room facilities. The presented method for preparing fiber optic plasmonic sensors provides high throughput and is perfectly suited for commercialization using batch processing. The transfer of the perforated gold film onto an optical fiber tip does not affect the sensitivity of the biosensor ((420 ±â€¯83) nm/refractive index unit (RIU)), which is comparable to sensitivities of sensor platforms based on periodic hole arrays in gold films prepared by significantly more complex methods. Furthermore, real-time and in-line immunoassay studies with a specially designed 3D printed flow cell are presented exploiting the presented optical fiber based biosensors.


Assuntos
Tecnologia de Fibra Óptica/instrumentação , Imunoensaio/instrumentação , Imunoglobulina G/análise , Ressonância de Plasmônio de Superfície/instrumentação , Animais , Desenho de Equipamento , Cabras , Ouro/química , Fibras Ópticas , Impressão Tridimensional , Coelhos , Refratometria/instrumentação
10.
Biosens Bioelectron ; 132: 38-46, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30851494

RESUMO

Early diagnosis of dengue biomarkers by employing a technology that is less labor- and time-intensive and offers higher sensitivity and lower limits of detection would find great significance in the developing world. Here, we report the development of a biosensor that exploits the localized surface plasmon resonance (LSPR) effect of silver nanostructures, created via thermal annealing of thin metal film, to detect dengue NS1 antigen, which appears as early as the onset of infection. The biosensor integrates membrane-based blood-plasma separation to develop lab-on-chip device that facilitates rapid diagnosis (within 30 min) of dengue NS1 antigen from a small volume (10 µL) of whole blood. The refractive index (RI) sensitivity of the LSPR biosensor was verified by using aqueous glycerol (0-100 wt%) which showed that it is sufficiently sensitive to detect 10-3 change in RI, which is comparable to that observed with protein-protein interaction. The RI sensitivity was utilized to demonstrate protein binding by using bovine serum albumin and detection of antibody-antigen immune reaction by binding human chorionic gonadotropin antigen to immunoglobulin antibody immobilized in our LSPR biosensor. Next, we demonstrated the detection of NS1 in plasma obtained via centrifugation and in plasma separated on-chip. From 10 µL of whole blood spiked with NS1 antigen, our biosensor reliably detects 0.06 µg/mL of NS1, which lies within the clinical limit observed during the first seven days of infection, with a sensitivity of 9 nm/(µg/mL). These results confirm that the proposed LSPR biosensor can potentially be used in point-of-care dengue diagnostics.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/sangue , Nanoestruturas/química , Prata/química , Ressonância de Plasmônio de Superfície/instrumentação , Proteínas não Estruturais Virais/sangue , Adulto , Anticorpos Imobilizados/química , Coleta de Amostras Sanguíneas/instrumentação , Dengue/diagnóstico , Humanos , Dispositivos Lab-On-A-Chip , Limite de Detecção
11.
Opt Lett ; 44(5): 1134-1137, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30821731

RESUMO

As technology continues to advance, the development of novel sensing systems opens new possibilities for low-cost, practical biosensing applications. In this Letter, we demonstrate a localized surface plasmon resonance system that combines both wave-guiding and plasmonic resonance sensing with a single microstructured polymeric structure. Characterizing the sensor using the finite element method simulation shows, to the best of our knowledge, a record wavelength sensitivity (WS) of 111000 nm/refractive index unit (RIU), high amplitude sensitivity (AS) of 2050 RIU-1, high sensor resolution and limit of detection of 9×10-7 RIU and 8.12×10-12 RIU2/nm, respectively. Furthermore, these sensors have the capability to detect an analyte within the refractive index range of 1.33-1.43 in the visible to mid-IR, therefore being potentially suitable for applications in biomolecular and chemical analyte detection.


Assuntos
Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Análise de Elementos Finitos , Limite de Detecção
12.
Appl Opt ; 58(7): 1824-1829, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30874222

RESUMO

A surface plasmon resonance biosensor based on a graphene-decorated grating excitation structure is proposed in this paper. The biosensor consists of a three-layer structure, including a graphene layer, a grating layer, and a high refractive index layer. The material of the grating layer is silica. The graphene is physically deposited on the grating ridges. An incident light with transverse magnetic polarization is used to excite surface plasmons in the mid-infrared spectral region, which is highly localized at both ends of the graphene layer. The property of the sensor is improved by the high refractive index dielectric layer, which enhances the absorption of incident light and increases the depth of the spectra. The finite-difference time-domain method is used to simulate the property of the sensor. The structure of the sensor could be optimized by changing the structural parameters and comparing the simulation results. The effective refractive index (RI) on the surface and the wavelength of the reflective resonance absorption peak will be changed when the surface of graphene adsorbs the surrounding analyte. The results show that the relationship between the analyte RI and the resonance wavelength is linear. The measurement range of analyte RI is 1-1.8, and the sensitivity is 2780 nm/RIU.


Assuntos
Grafite/química , Fenômenos Ópticos , Ressonância de Plasmônio de Superfície/instrumentação , Simulação por Computador , Refratometria , Dióxido de Silício/química
13.
Anal Bioanal Chem ; 411(7): 1311-1318, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30719562

RESUMO

The development of a sensitive and specific detection platform for exosomes is highly desirable as they are believed to transmit vital tumour-specific information (mRNAs, microRNAs, and proteins) to remote cells for secondary metastasis. Herein, we report a simple method for the real-time and label-free detection of clinically relevant exosomes using a surface plasmon resonance (SPR) biosensor. Our method shows high specificity in detecting BT474 breast cancer cell-derived exosomes particularly from complex biological samples (e.g. exosome spiked in serum). This approach exhibits high sensitivity by detecting as low as 8280 exosomes/µL which may potentially be suitable for clinical analysis. We believe that this label-free and real-time method along with the high specificity and sensitivity may potentially be useful for clinical settings.


Assuntos
Exossomos/patologia , Neoplasias/diagnóstico , Ressonância de Plasmônio de Superfície/métodos , Neoplasias da Mama/sangue , Neoplasias da Mama/diagnóstico , Linhagem Celular Tumoral , Desenho de Equipamento , Feminino , Humanos , Masculino , Neoplasias/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/diagnóstico , Ressonância de Plasmônio de Superfície/instrumentação
14.
Anal Bioanal Chem ; 411(11): 2249-2259, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30798337

RESUMO

Remote detection by surface plasmon resonance (SPR) is demonstrated through microstructured optical arrays of conical nanotips or micropillars. Both geometries were fabricated by controlled wet chemical etching of bundles comprising several thousands of individual optical fibers. Their surface was coated by a thin gold layer in order to confer SPR properties. The sensitivity and resolution of both shapes were evaluated as a function of global optical index changes in remote detection mode performed by imaging through the etched optical fiber bundle itself. With optimized geometry of micropillar arrays, resolution was increased up to 10-4 refractive index units. The gold-coated micropillar arrays were functionalized with DNA and were able to monitor remotely the kinetics of DNA hybridization with complementary strands. We demonstrate for the first time highly parallel remote SPR detection of DNA via microstructured optical arrays. The obtained SPR sensitivity combined with the remote intrinsic properties of the optical fiber bundles should find promising applications in biosensing, remote SPR imaging, a lab-on-fiber platform dedicated to biomolecular analysis, and in vivo endoscopic diagnosis. Graphical abstract We present a single fabrication step to structure simultaneously all the individual cores of an optical fiber bundle composed of thousands of fibers. The resulting sensor is optimized for reflection mode (compatible with in vivo applications) and is used to perform for the first time highly parallel remote SPR detection of DNA via several thousands of individual optical fiber SPR sensors paving the way for multiplexed biological detection.


Assuntos
DNA/análise , Hibridização de Ácido Nucleico , Fibras Ópticas , Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Tecnologia de Fibra Óptica/instrumentação , Ouro/química , Ácidos Nucleicos Imobilizados/química , Refratometria
15.
Talanta ; 194: 289-297, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30609533

RESUMO

In this study we developed an optical fiber biosensor able to detect the presence of naphthalene in sea-water. With this aim, we designed and produced an antibody specific for the naphthalene molecule. The capability of the antibody to bind to naphthalene was characterized by ELISA tests. A surface plasmon resonance (SPR) sensor platform was realized by sputtering a gold layer on a modified plastic optical fiber (POF). The gold surface was derivatizated and functionalized with the produced antibody by using the EDC/NHS amino-coupling immobilization protocol. The obtained results indicated that the POF-biosensor is able to sense the presence of naphthalene in a sea-water solution. The limit of detection (LOD) value was calculated to be 0.76 ng/mL, a value lower than the maximum residue limit value of naphthalene (0.13 µg/mL) referred as the water environmental quality standards (EQS). In addition, to the high sensitivity of the assay, it is remarkable to point out the possibility to monitor the presence of naphthalene in a real sea water solution by exploiting a simple experimental setup with a remote sensing capability offered by the POF-biosensor.


Assuntos
Naftalenos/análise , Fibras Ópticas , Água do Mar/química , Ressonância de Plasmônio de Superfície/instrumentação , Limite de Detecção
16.
Nat Commun ; 10(1): 28, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30604756

RESUMO

MicroRNA exhibits differential expression levels in cancer and can affect cellular transformation, carcinogenesis and metastasis. Although fluorescence techniques using dye molecule labels have been studied, label-free molecular-level quantification of miRNA is extremely challenging. We developed a surface plasmon resonance sensor based on two-dimensional nanomaterial of antimonene for the specific label-free detection of clinically relevant biomarkers such as miRNA-21 and miRNA-155. First-principles energetic calculations reveal that antimonene has substantially stronger interaction with ssDNA than the graphene that has been previously used in DNA molecule sensing, due to thanking for more delocalized 5s/5p orbitals in antimonene. The detection limit can reach 10 aM, which is 2.3-10,000 times higher than those of existing miRNA sensors. The combination of not-attempted-before exotic sensing material and SPR architecture represents an approach to unlocking the ultrasensitive detection of miRNA and DNA and provides a promising avenue for the early diagnosis, staging, and monitoring of cancer.


Assuntos
Antimônio/química , Técnicas Biossensoriais/instrumentação , Grafite/química , MicroRNAs/isolamento & purificação , Ressonância de Plasmônio de Superfície/instrumentação , Biomarcadores Tumorais/isolamento & purificação , Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/isolamento & purificação , Humanos , Dispositivos Lab-On-A-Chip , Limite de Detecção , Nanoestruturas/química , Neoplasias/diagnóstico , Neoplasias/genética , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície/métodos
17.
J Pharm Biomed Anal ; 163: 211-216, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30321785

RESUMO

A surface plasmon resonance (SPR) based immunosensor is presented for highly sensitive and selective detection of 17ß-estradiol by the indirect competitive inhibition immuno assay, employing anti-17 ß-estradiol antibody as high molecular weight (HMW) interactant. Immobilization of estradiol-BSA conjugate onto the nano thin gold surface was accomplished by covalent amide linkage through self assembled monolayer. The proposed biosensor is simple to fabricate, reproducible and exhibit excellent sensitivity for estrogen (detection limit,1 pg mL-1) without any significant interference from structurally similar steroidal hormone, progesterone and non-steroidal compound bisphenol-A. The proposed surface displayed a high level of stability during repeated regeneration and immunoreaction cycles suitable for biosensor development.


Assuntos
Anticorpos/imunologia , Técnicas Biossensoriais/métodos , Estradiol/análise , Ressonância de Plasmônio de Superfície/métodos , Anticorpos/química , Técnicas Biossensoriais/instrumentação , Estradiol/imunologia , Técnica Indireta de Fluorescência para Anticorpo/instrumentação , Técnica Indireta de Fluorescência para Anticorpo/métodos , Fluorimunoensaio/instrumentação , Fluorimunoensaio/métodos , Ouro/química , Nanopartículas Metálicas/química , Peso Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície/instrumentação
18.
Methods Mol Biol ; 1860: 199-210, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30317506

RESUMO

Surface plasmon resonance (SPR) can be used to analyze both binding affinities and kinetic parameters between a ligand and an analyte. SPR can be performed by either cross-linking a given ligand to a sensor chip covalently or utilizing high-affinity non-covalent interactions to secure a ligand in a particular conformation to a chip, both of which have their potential advantages. SPR measurements are mass based and reflect the proportional amount of analyte bound to a given ligand at a given concentration when flowed at a set rate in order to determine the binding parameters of a given biochemical interaction. The resultant sensorgram can indicate different types of binding events as well as provide both ka and kd, which can be used to determine an equilibrium dissociation constant KD. SPR can be used to measure binding affinity of proteins involved in fusion such as between SNAREs, SNAREs, and proteins that interact with them such as Sec18 (NSF) or Sec17 (alpha-SNAP), or to measure the binding of any fusion-related protein to a specific lipid or other small molecules; however, KDs are determined by SPR using a titration of concentrations of analyte and a maximum point on the sensorgram signifying saturation of the protein in order to determine a steady-state KD.


Assuntos
Ligação Proteica , Proteínas SNARE/metabolismo , Ressonância de Plasmônio de Superfície/métodos , Cinética , Ligantes , Lipídeos , Fusão de Membrana , Proteínas Sensíveis a N-Etilmaleimida/química , Proteínas Sensíveis a N-Etilmaleimida/metabolismo , Nanoestruturas/química , Proteínas SNARE/química , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/química , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/metabolismo , Ressonância de Plasmônio de Superfície/instrumentação
19.
Biosensors (Basel) ; 8(3)2018 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-30149679

RESUMO

The notion of surface plasmon resonance (SPR) sensor research emerged more than eight decades ago from the first observed phenomena in 1902 until the first introduced principles for gas sensing and biosensing in 1983. The sensing platform has been hand-in-hand with the plethora of sensing technology advancement including nanostructuring, optical technology, fluidic technology, and light source technology, which contribute to substantial progress in SPR sensor evolution. Nevertheless, the commercial products of SPR sensors in the market still require high-cost investment, component, and operation, leading to unaffordability for their implementation in a low-cost point of care (PoC) or laboratories. In this article, we present a comprehensive review of SPR sensor development including the state of the art from a perspective of light source technology trends. Based on our review, the trend of SPR sensor configurations, as well as its methodology and optical designs are strongly influenced by the development of light source technology as a critical component. These simultaneously offer new underlying principles of SPR sensor towards miniaturization, portability, and disposability features. The low-cost solid-state light source technology, such as laser diode, light-emitting diode (LED), organic light emitting diode (OLED) and smartphone display have been reported as proof of concept for the future of low-cost SPR sensor platforms. Finally, this review provides a comprehensive overview, particularly for SPR sensor designers, including emerging engineers or experts in this field.


Assuntos
Técnicas Biossensoriais/métodos , Dispositivos Ópticos , Ressonância de Plasmônio de Superfície/métodos , Técnicas Biossensoriais/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação
20.
Molecules ; 23(7)2018 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-30011941

RESUMO

In order to overcome the existing challenges presented by conventional sensors, including their large size, a complicated preparation process, and difficulties filling the sensing media, a novel high-sensitivity plasmonic resonator sensor which is composed of two graphene-modified straight waveguides, two metallic layers, and a racetrack nanodisk resonator is proposed in this study. The transmission characteristics, which were calculated by the finite element theory, were used to further analyze the sensing properties. The results of quantitative analysis show that the proposed plasmonic sensor generates two resonance peaks for the different incident wavelengths, and both resonance peaks can be tuned by temperature. In addition, after optimizing the structural parameters of the resonator, the Q value and the refractive sensitivity reached 21.5 and 1666.67 nmRIU⁻1, respectively. Compared with other studies, these values translate to a better performance. Furthermore, a temperature sensitivity of 2.33 nm/5°C was achieved, which allows the sensor to be easily applied to practical detection. The results of this study can broaden the useful range for a nanometer-scale temperature sensor with ultrafast real-time detection and resistance to electromagnetic interference.


Assuntos
Grafite/química , Ressonância de Plasmônio de Superfície/instrumentação , Ressonância de Plasmônio de Superfície/métodos
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