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1.
Chem Commun (Camb) ; 55(67): 9967-9970, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31367705

RESUMO

Herein, a seesaw ratiometric (SR) probe is designed which integrates fluorescence and surface enhanced Raman scattering (SERS) technology. Fluorescence imaging enables tracking of the spatiotemporal dynamic behaviour of telomerase. Meanwhile, SERS reverse ratiometric measurement can enable sensitive detection of telomerase activity in single living cells.


Assuntos
Corantes/química , Imagem Óptica/métodos , Análise de Célula Única/métodos , Análise Espectral Raman/métodos , Telomerase/metabolismo , DNA/química , Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Humanos , Células MCF-7 , Nanopartículas Metálicas/química
2.
J Biomed Nanotechnol ; 15(10): 2130-2141, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31462377

RESUMO

We synthesized a new surface enhanced Raman scattering nanoparticle (SERS NP) which can detect reactive oxygen species (ROS) and thus changes in oxidative stress (OS). Our SERS NP was synthesized using a gold nanoparticle (AuNP) core which was then coated with a dihydrorhodamine (DHR123) Raman layer. In the presence of ROS, DHR123 is converted to rhodamine123 (Rd123) which has a distinct Raman fingerprint. Next, AuNP-DHR123 were encapsulated in a mesoporous-SiO2 shell to help appose DHR123 to the AuNP core. Finally, the AuNP-DHR123-mesoporous-SiO2 was functionalized with cystine knot peptides that target integrin αvß6. Our SERS NP was initially optimized in vitro using solutions containing reactive oxygen species as well as human cancer cell lines. Finally, in a xenograft animal model, we demonstrated the in vivo ability of our SERS NP to target a tumor, as well as provide a reading of the amount of OS within the tumor.


Assuntos
Nanopartículas Metálicas , Neoplasias , Animais , Ouro , Humanos , Estresse Oxidativo , Dióxido de Silício , Análise Espectral Raman
3.
Phys Chem Chem Phys ; 21(35): 19288-19297, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31451821

RESUMO

This paper reports a facile, fast, and cost-effective method for the synthesis of three-dimensional (3D) porous AgNPs/Cu composites as SERS substrates for the super-sensitive and quantitative detection of food organic contaminations. Due to the 3D porous hotspot architecture and the strong plasmonic coupling between Ag and Cu, the porous AgNPs/Cu substrate achieves ultrasensitive detection of multiple analytes as low as 10-11 M (crystal violet, CV), 10-9 M (malachite green, MG), 10-11 M (acephate), and 10-9 M (thiram) even with a portable Raman device. Moreover, this 3D solid substrate has good signal uniformity (RSD < 11%) and superior stability (<14% signal loss), allowing for practical SERS detections. Importantly, by simply wiping the real sample surface using the substrate, it successfully detects CV and MG residues on crayfish, and the limit of detection (LOD) of CV and MG is determined to be 1.14 × 10-9 M and 0.94 × 10-7 M, respectively. Further, the substrate can also be applied to detect acephate on eggplant with a LOD of 1.41 × 10-9 M and thiram on an apple surface with a LOD of 1.04 × 10-7 M. Note that all these SERS detections on real samples have a broad dynamic concentration range and a good linear dependence. As a "proof of concept", multi-component detection on a real sample has also been demonstrated. This 3D solid substrate possesses excellent detection sensitivity, diversity, and accuracy, which allows rapid and reliable determination of toxic substances in foods.


Assuntos
Técnicas de Química Analítica/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Praguicidas/análise , Análise Espectral Raman , Animais , Técnicas de Química Analítica/economia , Cobre/química , Limite de Detecção , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Prata/química
4.
Medicine (Baltimore) ; 98(34): e16940, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31441886

RESUMO

BACKGROUND: The clinical significance of Raman spectroscopy (RS) in colorectal cancer (CRC) patients still remains underestimated. We performed this meta-analysis to elucidate the diagnostic value in CRC patients. METHODS: We systematically searched electronic databases for published articles. Fixed effect model and random effect model were used to calculate the pooled sensitivity, specificity, diagnostic accuracy, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and positive posttest probability (PPP) of CRC. Meta-regression and subgroup analysis were conducted to assess potential source of heterogeneity. We also used Egger linear regression tests to assess risk of publication bias. RESULTS: Thirteen studies had been included (679 patients: 186 with premalignant lesions and 493 with malignant lesions). The pooled sensitivity, specificity, diagnostic accuracy, PLR, NLR, DOR and PPP for CRC screening using RS were 0.94 (0.92-0.96), 0.94 (0.88-0.97), 0.96 (0.94-0.98), 16.44 (7.80-34.63), 0.062 (0.043-0.090), 263.65 (99.03-701.96) and 86%, respectively. CONCLUSION: RS is a potentially useful tool for future CRC screening. It also offers potentially early detection for CRC patients.


Assuntos
Adenoma/diagnóstico , Neoplasias Colorretais/diagnóstico , Análise Espectral Raman , Diagnóstico Precoce , Feminino , Humanos , Masculino , Valor Preditivo dos Testes
5.
J Phys Chem Lett ; 10(15): 4374-4381, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31313926

RESUMO

Voltage imaging allows mapping of the membrane potential in living cells. Yet, current intensity-based imaging approaches are limited to relative membrane potential changes, missing important information conveyed by the absolute value of the membrane voltage. This challenge arises from various factors affecting the signal intensity, such as concentration, illumination intensity, and photobleaching. Here, we demonstrate electronic preresonance hyperspectral stimulated Raman scattering (EPR-hSRS) for spectroscopic detection of the membrane voltage using a near-infrared-absorbing microbial rhodopsin expressed in E. coli. This newly developed near-infrared active microbial rhodopsin enables electronic preresonance SRS imaging at high sensitivity. By spectral profiling, we identified voltage-sensitive SRS peaks in the fingerprint region in single E. coli cells. These spectral signatures offer a new approach for quantitation of the absolute membrane voltage in living cells.


Assuntos
Rodopsinas Microbianas/química , Análise Espectral Raman/métodos , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Raios Infravermelhos , Potenciais da Membrana , Mutação , Rodopsinas Microbianas/genética , Rodopsinas Microbianas/metabolismo , Análise de Célula Única/métodos
7.
Chem Commun (Camb) ; 55(65): 9697-9700, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31347623

RESUMO

An ultra-high sensitivity sensor with the function of chiral signal amplification has been proposed for the enantiomer discrimination of various amino acid enantiomers based on charge transfer (CT)-induced SERS spectroscopy. The introduced TiO2 in this sensor improves the CT behavior and discrimination efficiency distinctly and enantiomeric discrimination is realized even at low concentration.


Assuntos
Compostos de Anilina/química , Nanopartículas Metálicas/química , Compostos de Sulfidrila/química , Triptofano/análise , beta-Ciclodextrinas/química , Ligações de Hidrogênio , Fenilalanina/análise , Fenilalanina/química , Prata/química , Análise Espectral Raman/métodos , Estereoisomerismo , Titânio/química , Triptofano/química , Tirosina/análise , Tirosina/química
8.
Anal Bioanal Chem ; 411(21): 5509-5518, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31280475

RESUMO

The rapid analysis and detection of biomolecules has become increasingly important in biological research. Hence, here we propose a novel suspension array method that is based on gold nanorod (AuNR)-enhanced Raman spectroscopy and uses micro-quartz pieces (MQPs) as microcarriers. AuNRs and Raman reporter molecules are coupled together by Au-S bonds to obtain surface-enhanced Raman scattering labels (SERS labels). The SERS labels are then assembled on the surfaces of the MQPs via electrostatic interactions, yielding encoded MQPs. Experimental results showed that the encoded MQPs could be decoded using a Raman spectrometer. A multiplex immunoassay experiment demonstrated the validity and specificity of these encoded MQPs when they were used for bioanalysis. In concentration gradient experiments, the proposed method was found to give a linear concentration response to the target biomolecule at target concentrations of 0.46875-30 nM, and the detection limit was calculated to be 1.78 nM. The proposed method utilizes MQPs as carriers rather than conventional microbeads, which allows the interference caused by the background fluorescence of microbeads to be eliminated. The fluorescence of the encoded MQPs can be simply, rapidly, and inexpensively quantified using fluorescence microscopy. By dividing the quantitative and qualitative detection of biomolecules into two independent channels, crosstalk between the encoded signal and the labeled signal is averted and high decoding accuracy and detection sensitivity are guaranteed. Graphical abstract.


Assuntos
Ouro/química , Nanotubos/química , Quartzo , Análise Espectral Raman/métodos
9.
Chem Commun (Camb) ; 55(57): 8329-8332, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31257378

RESUMO

Cell imaging heavily depends on fluorescent labels typically incompatible with Raman microscopy. The europium(iii) complex based on dipicolinic acid (DPA) presented here is an exception from this rule. Although its luminescence bands are very narrow, their intensity is comparable to the background Raman bands. This makes it complementary to less luminous compounds referred to as Raman tags. Through several examples we show that the complex provides a morphological context in otherwise unstained cells, thus acting as a spectral-counterstaining agent.


Assuntos
Complexos de Coordenação/química , Análise Espectral Raman , Candida albicans/metabolismo , Parede Celular/química , Células Epiteliais/química , Células Epiteliais/citologia , Európio/química , Células HeLa , Humanos , Microscopia de Fluorescência , Ácidos Picolínicos/química
10.
Chem Commun (Camb) ; 55(63): 9379-9382, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31317975

RESUMO

Small-molecule natural products have been an essential source of pharmaceuticals to treat human diseases, but very little is known about their behavior inside dynamic, live human cells. Here, we demonstrate the first structure-activity-distribution relationship (SADR) study of complex natural products, the anti-cancer antimycin-type depsipeptides, using the emerging bioorthogonal Stimulated Raman Scattering (SRS) Microscopy. Our results show that the intracellular enrichment and distribution of these compounds are driven by their potency and specific protein targets, as well as the lipophilic nature of compounds.


Assuntos
Antimicina A/análogos & derivados , Antineoplásicos/química , Depsipeptídeos/química , Antimicina A/química , Antimicina A/metabolismo , Antimicina A/farmacologia , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Depsipeptídeos/metabolismo , Depsipeptídeos/farmacologia , Células HeLa , Humanos , Células MCF-7 , Microscopia de Fluorescência , Análise Espectral Raman , Relação Estrutura-Atividade
11.
Analyst ; 144(17): 5232-5244, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31360935

RESUMO

Leishmaniasis comprises a group of infectious diseases with worldwide distribution, of which both the visceral and cutaneous forms are caused by Leishmania parasites. In the absence of vaccines, efficacious chemotherapy remains the basis for leishmaniasis control. The available drugs are expensive and associated with several secondary adverse effects. Due to these limitations, the development of new antileishmanial compounds is imperative, and plants offer various perspectives in this regard. The present study evaluated the in vitro leishmanicidal activity of flavonoids isolated from Solanum paludosum Moric. and investigated the mechanisms of cell death induced by them. These compounds were evaluated in vitro for their antileishmanial activity against Leishmania amazonensis promastigotes and they showed prominent leishmanicidal activity. The EtOAc fraction, gossypetin 3,7,8,4'-tetra-O-methyl ether (1), and kaempferol 3,7-di-O-methyl ether (3) were selected to be used in an in vitro assay against L. amazonensis amastigotes and cell death assays. The flavonoids (1) and (3) presented significant activity against L. amazonensis amastigotes, exhibiting the IC50 values of 23.3 ± 4.5 µM, 34.0 ± 9.6 µM, and 10.5 ± 2.5 µM for the EtOAc fraction, (1), and (3), respectively, without toxic effects to the host cells. Moreover, (1) and (3) induced blocked cell cycle progression at the G1/S transition, ultimately leading to G1/G0 arrest. Flavonoid (3) also induced autophagy. Using Raman spectroscopy in conjunction with principal component analysis, the biochemical changes in the cellular components induced by flavonoids (1) and (3) were presented. The obtained results indicated that the mechanisms of action of (1) and (3) occurred through different routes. The results support that the flavonoids derived from S. paludosum can become lead molecules for the design of antileishmanial prototypes.


Assuntos
Antiprotozoários/farmacologia , Morte Celular/efeitos dos fármacos , Flavonoides/farmacologia , Citometria de Fluxo/métodos , Leishmania/efeitos dos fármacos , Animais , Antiprotozoários/química , Autofagia/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Flavonoides/química , Quempferóis/química , Quempferóis/farmacologia , Leishmania/citologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Análise Espectral Raman , Estreptófitas/química
12.
J Agric Food Chem ; 67(31): 8641-8648, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31322878

RESUMO

Prochloraz is a widely used imidazole fungicide that has to be analyzed together with its metabolites or transformation products for food safety monitoring purposes in the European Union. Although the focus in food of plant origin has been set on metabolites BTS 44595 and BTS 44596, we consider relevant the study of BTS 40348 metabolite, too, because it has been detected in both raw and processed foods based on citrus fruits in the EU. Metabolite BTS 40348 should be monitored in surface water due to its ecotoxicological effects. In this work, the synthesis and structural characterization of BTS 40348 metabolite of fungicide prochloraz is presented, because the structure is closely related to the chemistry and biological activity of the substance. Characterization using 13C and 1H NMR, infrared (IR), and Raman spectroscopy is detailed, together with confirmation by electrospray mass spectrometry analysis.


Assuntos
Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Imidazóis/química , Imidazóis/metabolismo , União Europeia , Fast Foods/análise , Contaminação de Alimentos/análise , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Resíduos de Praguicidas/química , Resíduos de Praguicidas/metabolismo , Análise Espectral Raman , Poluentes da Água/química
13.
Environ Sci Process Impacts ; 21(7): 1076-1084, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31241094

RESUMO

Dissolved organic matter (DOM) is a common solute in snow and ice at Earth's surface. Its effects on reaction kinetics in ice and at air-ice interfaces can be large, but are currently difficult to quantify. We used Raman microscopy to characterize the surface and bulk of frozen aqueous solutions containing humic acid, sodium dodecyl sulfate (SDS), and citric acid at a range of concentrations and temperatures. The surface-active species (humic acid and SDS) were distributed differently than citric acid. Humic acid and SDS are almost completely excluded to the air-ice interface during freezing, where they form a film that coats the surface nearly completely. A liquid layer that coats the majority of the surface was observed at all humic acid and SDS concentrations. Citric acid, which is smaller and less surface active, is excluded to liquid channels at the air-ice interface and within the ice bulk, as has previously been reported for ionic solutes such as sodium chloride. Incomplete surface wetting was observed at all citric acid concentrations and at all temperatures (up to -5 °C). Citric acid appears to be solvated in frozen samples, but SDS and humic acid do not. These results will improve our understanding of the effects of organic solutes on environmental and atmospheric chemistry within ice and at air-ice interfaces.


Assuntos
Ar/análise , Substâncias Húmicas/análise , Camada de Gelo/química , Ácido Cítrico/análise , Temperatura Baixa , Congelamento , Cinética , Modelos Teóricos , Dodecilsulfato de Sódio/análise , Solubilidade , Soluções , Análise Espectral Raman , Tensoativos/análise
14.
Photochem Photobiol Sci ; 18(8): 1933-1944, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31169269

RESUMO

Although natural exposure to ambient UV radiation in oligotrophic seawater at small depths can reach the levels responsible for cellular damage, the sea urchin Paracentrotus lividus is frequently in such sites, particularly on the southern Adriatic Sea shore. Spawning their eggs and spending their early life stage in rocky shores at depths of 0.5-2 m are the results of their successful adaptation strategies, although adults may dwell at greater depths. Surprisingly, there is a paucity of reports regarding the carotenoid content in sea urchin eggs. Beyond their important role in photoprotection against high UV exposure, cell division and early development, the content and distribution of carotenoids contribute to the successful survival of sea urchins and also determine the color of their gonads (roe), which is of commercial importance as a delicacy. Herein, for the first time, we have described the carotenoid content and distribution in intact, freshly released eggs of P. lividus species, non-destructively employing resonance Raman spectroscopy and imaging; near-infrared Raman spectroscopy revealed additional molecular carotenoid content. Echinenone and ß-carotene resonance Raman signals were the most intense, and they were identified as the principal carotenoids that are preferentially accumulated in eggs rather than in gonads. Raman imaging in confocal mode revealed the uniform distribution of the carotenoid signal over the whole eggs, while the distribution of proteins appeared spotted. Egg carotenoids generally maintained their identity after 2 months of dry storage, with slight signs of C[double bond, length as m-dash]C bond oxidation. The potential utilization of P. lividus sea urchin eggs as valuable microsphere packages of native carotenoids is discussed.


Assuntos
Carotenoides/análise , Ovos/análise , Microesferas , Ouriços-do-Mar/química , Ouriços-do-Mar/citologia , Animais , Análise Espectral Raman
15.
Chemistry ; 25(45): 10566-10570, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31197892

RESUMO

A family of three neutral iridium(III) tetrazolato complexes are investigated as bacterial imaging agents. The complexes offer a facile tuning of the emission colour from green (520 nm) to red (600 nm) in aqueous media, while keeping the excitation wavelength unchanged. The three complexes do not inhibit the bacterial growth of Bacillus Cereus, used as a model in this study, and exhibit extremely fast cellular uptake. After a minute incubation time, the nontoxic complexes show subcellular localisation in spherical structures identified as lipid vacuoles. Confocal Raman imaging has been exploited for the first time on live bacteria, to provide direct and label-free mapping of the lipid-enriched organelles within B. cereus, complementing the use of luminescent probes. Examination of the Raman spectra not only confirmed the presence of lipophilic inclusions in B. cereus but offered additional information about their chemical composition, suggesting that the lipid vacuoles may contain polyhydroxybutyrate (PHB).


Assuntos
Bacillus cereus/metabolismo , Complexos de Coordenação/química , Irídio/química , Lipídeos/química , Microscopia Confocal/métodos , Complexos de Coordenação/metabolismo , Substâncias Luminescentes/química , Análise Espectral Raman
16.
Food Chem ; 297: 124881, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253314

RESUMO

Imaging the microstructure of opaque composite foodstuffs and extracting quantitative chemical information about specific localized components is challenging. Herein, a method has been developed to determine spatially resolved concentrations of aqueous salt and applied to measure salt concentrations of water droplets in butter samples. This was done using Coherent Anti-Stokes Raman Scattering (CARS) microscopy which achieves non-invasive label free imaging based on visualization of specific chemical-bond vibrations. The concentration of salt in the dispersed water droplets in butter was determined based on the relative change in intensity of the CARS-signal at two distinct wavenumbers, which have been shown to be dependent on the inter-molecular coupling of water molecules and salt. The results provide the size and salt concentration distribution of the droplets in the samples. It is further shown that the average salt concentration in the whole sample can correctly be inferred from the concentration measured within the water droplets.


Assuntos
Manteiga/análise , Cloreto de Sódio/análise , Análise Espectral Raman/métodos , Análise de Alimentos , Microscopia , Óleos/química , Água/química
17.
Mar Pollut Bull ; 142: 384-393, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232316

RESUMO

Methods standardisation in microplastics research is needed. Apart from reagent-dependent effects on microplastics, varying target particle sizes can hinder result comparison between studies. Human health concerns warrant recovery of small microplastics. We compared existing techniques using hydrogen peroxide, Proteinase-K, Trypsin and potassium hydroxide to digest bivalve tissue. Filterability, digestion efficacy, recoverability of microplastics and subsequent polymer identification using Raman spectroscopy and a matching software were assessed. Only KOH allowed filtration at ≤25 µm. When adding a neutralisation step prior to filtration, KOH digestates were filterable using 1.2-µm filters. Digestion efficacies were >95.0% for oysters, but lower for clams. KOH destroyed rayon at 60 °C but not at 40 °C. Acrylic fibre identification was affected due to changes in Raman spectra peaks. Despite those effects, we recommend KOH as the most viable extraction method for exposure risk studies, due to microplastics recovery from bivalve tissues of single-digit micrometre size.


Assuntos
Bivalves/química , Filtração/métodos , Hidróxidos/química , Plásticos/isolamento & purificação , Compostos de Potássio/química , Poluentes Químicos da Água/isolamento & purificação , Animais , Ecotoxicologia/métodos , Endopeptidase K/química , Contaminação de Alimentos/análise , Peróxido de Hidrogênio/química , Plásticos/análise , Software , Análise Espectral Raman/métodos , Tripsina/química , Poluentes Químicos da Água/análise
18.
Anal Bioanal Chem ; 411(21): 5445-5454, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31152224

RESUMO

Bacteremia with its high mortality is a frequent case in clinical health care. Further, bacteremia includes the considerable risk of progressing to a sepsis. Even in case of survival, sepsis still entails diminished quality of life for the survivors and high indirect cost for the society. The crucial factor in sepsis is time. Therefore, timely description of adequate antibiotics is vital to reduce mortality and improve quality of life after survival. Despite that, the current gold standard of clinical bacteria diagnostic is based on cultivation of bacteria, which requires an average of 13-h cultivation. Consequently, there is a necessity for culture free identification methods without sacrificing the range of bacteria strains which can be identified. Raman microspectroscopy in general requires only single bacteria cells and has proven to offer high identification accuracies. However, the prerequisite for Raman microspectroscopy is a suitable isolation strategy to obtain single unharmed bacteria cells free from matrix. Moreover, in blood, bacteria are outnumbered by billions of blood cells. In this study, we present an isolation strategy to recover single bacteria cells from blood and evaluate their suitability for Raman microspectroscopic identification. Graphical abstract.


Assuntos
Bactérias/classificação , Análise Espectral Raman/métodos , Bacteriemia/microbiologia , Bactérias/isolamento & purificação , Humanos , Qualidade de Vida , Sepse/microbiologia , Especificidade da Espécie
19.
Anal Bioanal Chem ; 411(17): 3801-3810, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31172237

RESUMO

The convenience of colorimetric sensors is useful for practical applications. In this work, we constructed a novel colorimetric sensor with magnetic separation ability that can be operated in nearly neutral conditions and achieve one-step detection of metabolites. Magnetic Cu doped Fe3O4@FeOOH magnetic nanocomposite (Cu/Fe3O4@FeOOH) with an oxygen vacancy was prepared by a one-step self-assembly hydrothermal method, and fully characterized by different methods. The oxygen vacancy generated by the incorporation of Cu2+ cations into the Fe3O4@FeOOH structure was confirmed to be a vital reactive site for enhancing the catalytic activity, which opens up a new way of designing highly efficient enzyme mimics. Benefiting from its inherent horseradish-peroxidase-like activity, a simple and selective enzyme-based colorimetric sensor was developed for one-step detection of H2O2 and cholesterol, and 3,3',5,5'-tetramethylbenzidine was catalyzed by H2O2 to generate a colored product of oxidized 3,3',5,5'-tetramethylbenzidine for signaling. H2O2 and cholesterol can be linearly detected in the same range from 0.01 to 0.4 mmol L-1 with detection limits of 0.0075 mmol L-1 and 0.0082 mmol L-1, respectively. The proposed colorimetric sensor has satisfactory reusability, accuracy, and practicability in human serum samples, indicating its potential application for the detection of different metabolites in the fields of life science and analytical science. Graphical abstract.


Assuntos
Técnicas Biossensoriais/métodos , Colorimetria/métodos , Cobre/química , Óxido Ferroso-Férrico/química , Peroxidase do Rábano Silvestre/química , Concentração de Íons de Hidrogênio , Magnetismo , Nanopartículas Metálicas/química , Benzidinas/química , Colesterol/sangue , Espectroscopia de Ressonância de Spin Eletrônica , Peróxido de Hidrogênio/análise , Microscopia Eletrônica de Transmissão , Oxirredução , Espectroscopia Fotoeletrônica , Reprodutibilidade dos Testes , Análise Espectral Raman , Difração de Raios X
20.
Anal Bioanal Chem ; 411(20): 5175-5186, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187200

RESUMO

An ultrasensitive electrochemiluminescence (ECL) immunosensor for alpha-fetoprotein (AFP) detection based on a poly(aniline-luminol)/graphene oxide nanocomposite was developed. The nanocomposite, which was prepared using a fast and simple chemical oxidation strategy for the first time, showed excellent ECL performance. This outstanding ECL performance is due to the formation of poly(aniline-luminol) on the graphene oxide (GO) surface and the excellent electron-transfer properties of GO. Moreover, the poly(aniline-luminol)/graphene oxide nanocomposite has abundant amino groups at its surface, making it a good platform for biomacromolecule labeling. Using the nanocomposite, a novel ECL immunosensor for the determination of AFP was successfully developed. Anti-AFP was immobilized on the surface of a poly(aniline-luminol)/graphene oxide nanocomposite-modified electrode using a glutaraldehyde crosslinking method to form the ECL immunosensor. The AFP was then captured at the modified electrode surface through an antigen-antibody immunoreaction. When the AFP was captured by its antibody, the ECL intensity decreased. This ECL immunosensor for the detection of AFP exhibited a linear range of 1.7 × 10-12 to 1.7 × 10-8 mg mL-1 and a detection limit of 5 × 10-13 mg mL-1, indicating high sensitivity and linearity across a wide concentration range. Furthermore, the immunosensor was successfully applied to determine AFP in a real-world human serum sample. Graphical abstract A new poly(aniline-luminol)/graphene oxide nanocomposite was prepared using a fast and simple strategy for the first time, and an ultrasensitive electrochemiluminescence (ECL) immunosensor for alpha-fetoprotein (AFP) detection based on this nanocomposite was developed.


Assuntos
Compostos de Anilina/química , Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Grafite/química , Luminescência , Luminol/química , Nanocompostos/química , alfa-Fetoproteínas/análise , Humanos , Limite de Detecção , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos Testes , Soro , Espectrofotometria Ultravioleta , Análise Espectral Raman , alfa-Fetoproteínas/imunologia
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