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1.
Sci Rep ; 11(1): 4943, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33654146

RESUMEN

The pandemic of COVID-19 is continuously spreading, becoming a worldwide emergency. Early and fast identification of subjects with a current or past infection must be achieved to slow down the epidemiological widening. Here we report a Raman-based approach for the analysis of saliva, able to significantly discriminate the signal of patients with a current infection by COVID-19 from healthy subjects and/or subjects with a past infection. Our results demonstrated the differences in saliva biochemical composition of the three experimental groups, with modifications grouped in specific attributable spectral regions. The Raman-based classification model was able to discriminate the signal collected from COVID-19 patients with accuracy, precision, sensitivity and specificity of more than 95%. In order to translate this discrimination from the signal-level to the patient-level, we developed a Deep Learning model obtaining accuracy in the range 89-92%. These findings have implications for the creation of a potential Raman-based diagnostic tool, using saliva as minimal invasive and highly informative biofluid, demonstrating the efficacy of the classification model.


Asunto(s)
/diagnóstico , Saliva/química , Espectrometría Raman/métodos , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/análisis , Comorbilidad , Biología Computacional , Aprendizaje Profundo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distribución Normal , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
2.
Int J Nanomedicine ; 16: 1901-1911, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33707945

RESUMEN

Purpose: Developing a sensitive SERS-based method to quantitatively detect serum biomarkers (Aß1-42 and P-Tau-181) for the early diagnosis of Alzheimer's disease (AD). Methods: In this study, a novel SERS-based sandwich immunoassay, which consists of tannin-capped silver nanoparticles and magnetic graphene oxide (Fe3O4@GOs), was developed. We firstly applied this method for the detection of protein standards in buffer solution, obtaining the regression equation. Then, its potential value on real serum samples of AD was further explored. Results: The detection linear range of Aß1-42 and P-Tau-181 protein standards were observed to range from 100 pg mL-1 to 10 fg mL-1, 100 pg mL-1 to 1 fg mL-1 respectively. We finally explored clinical application of the proposed method in 63 serum samples. As a result, P-tau-181 differentiated AD from non-AD dementia patients (AUC = 0.770), with a more favored ROC than Aß1-42 (AUC = 0.383). Conclusion: The developed SERS-based immunoassay is successfully applied to the determination of Aß1-42 and P-Tau-181 in human serum specimens, which provides a promising tool for the early diagnosis of AD.


Asunto(s)
Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/sangre , Inmunoensayo/métodos , Sondas Moleculares/química , Plata/química , Espectrometría Raman/métodos , Péptidos beta-Amiloides/sangre , Benzoatos/química , Calibración , Femenino , Grafito/química , Humanos , Límite de Detección , Masculino , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Compuestos de Sulfhidrilo/química , Difracción de Rayos X , Proteínas tau/sangre
3.
Drug Test Anal ; 13(4): 734-746, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33646611

RESUMEN

The illicit drug overdose crisis in North America continues to devastate communities with fentanyl detected in the majority of illicit drug overdose deaths. The COVID-19 pandemic has heightened concerns of even greater unpredictability in the drug supplies and unprecedented rates of overdoses. Portable drug-checking technologies are increasingly being integrated within overdose prevention strategies. These emerging responses are raising new questions about which technologies to pursue and what service models can respond to the current risks and contexts. In what has been referred to as the epicenter of the overdose crisis in Canada, a multi-technology platform for drug checking is being piloted in community settings using a suite of chemical analytical methods to provide real-time harm reduction. These include infrared absorption, Raman scattering, gas chromatography with mass spectrometry, and antibody-based test strips. In this Perspective, we illustrate some advantages and challenges of using multiple techniques for the analysis of the same sample, and provide an example of a data analysis and visualization platform that can unify the presentation of the results and enable deeper analysis of the results. We also highlight the implementation of a various service models that co-exist in a research setting, with particular emphasis on the way that drug checking technicians and harm reduction workers interact with service users. Finally, we provide a description of the challenges associated with data interpretation and the communication of results to a diverse audience.


Asunto(s)
Sobredosis de Droga/diagnóstico , Drogas Ilícitas/análisis , Detección de Abuso de Sustancias/métodos , /epidemiología , Sobredosis de Droga/epidemiología , Cromatografía de Gases y Espectrometría de Masas/instrumentación , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Proyectos Piloto , Pruebas en el Punto de Atención , Tiras Reactivas/análisis , Espectrofotometría Infrarroja/instrumentación , Espectrofotometría Infrarroja/métodos , Espectrometría Raman/instrumentación , Espectrometría Raman/métodos , Detección de Abuso de Sustancias/instrumentación
4.
Biosensors (Basel) ; 11(3)2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33670852

RESUMEN

The diagnosis of respiratory viruses of zoonotic origin (RVsZO) such as influenza and coronaviruses in humans is crucial, because their spread and pandemic threat are the highest. Surface-enhanced Raman spectroscopy (SERS) is an analytical technique with promising impact for the point-of-care diagnosis of viruses. It has been applied to a variety of influenza A virus subtypes, such as the H1N1 and the novel coronavirus SARS-CoV-2. In this work, a review of the strategies used for the detection of RVsZO by SERS is presented. In addition, relevant information about the SERS technique, anthropozoonosis, and RVsZO is provided for a better understanding of the theme. The direct identification is based on trapping the viruses within the interstices of plasmonic nanoparticles and recording the SERS signal from gene fragments or membrane proteins. Quantitative mono- and multiplexed assays have been achieved following an indirect format through a SERS-based sandwich immunoassay. Based on this review, the development of multiplex assays that incorporate the detection of RVsZO together with their specific biomarkers and/or secondary disease biomarkers resulting from the infection progress would be desirable. These configurations could be used as a double confirmation or to evaluate the health condition of the patient.


Asunto(s)
/diagnóstico , Inmunoensayo/métodos , Virus de la Influenza A/aislamiento & purificación , Gripe Humana/diagnóstico , Espectrometría Raman/métodos , /instrumentación , Diseño de Equipo , Humanos , Inmunoensayo/instrumentación , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Espectrometría Raman/instrumentación
5.
J Agric Food Chem ; 69(5): 1667-1674, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33522812

RESUMEN

Pesticide residues in food have been a grave concern to consumers. Herein, we have developed a dual-mode SERS chip using Cu2O mesoporous spheres decorated with Ag nanoparticles (MCu2O@Ag NPs) as both sensing and degradation/clearing unit for rapid detection of pymetrozine and thiram pesticides in tea samples. Three kinds of chemometric algorithms were comparatively applied to analyze the collected SERS spectra of pesticides. In comparison, random frog-partial least squares achieved the best performance with root mean square error of prediction and residual predictive deviation values of 0.9871, 6.17, and 0.9873, 6.64 for pymetrozine and thiram, respectively. Additionally, the prepared SERS chip showed great photocatalytic activity to degrade pesticides under visible light irradiation. Through a facile method, this work presented a novel dual-functional SERS chip for the rapid detection and degradation of low-concentration pesticides in both environmental and food samples.


Asunto(s)
Contaminación de Alimentos/análisis , Residuos de Plaguicidas/química , Espectrometría Raman/métodos , Algoritmos , Luz , Límite de Detección , Nanopartículas del Metal/química , Plata/química , Espectrometría Raman/instrumentación
6.
Int J Mol Sci ; 22(4)2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33578653

RESUMEN

We present a template-assisted method for synthesizing nanogap shell structures for biomolecular detections based on surface-enhanced Raman scattering. The interior nanogap-containing a silver shell structure, referred to as a silver nanogap shell (Ag NGS), was fabricated on silver nanoparticles (Ag NPs)-coated silica, by adsorbing small aromatic thiol molecules on the Ag NPs. The Ag NGSs showed a high enhancement factor and good signal uniformity, using 785-nm excitation. We performed in vitro immunoassays using a prostate-specific antigen as a model cancer biomarker with a detection limit of 2 pg/mL. To demonstrate the versatility of Ag NGS nanoprobes, extracellular duplex surface-enhanced Raman scattering (SERS) imaging was also performed to evaluate the co-expression of cancer biomarkers, human epidermal growth factor-2 (HER2) and epidermal growth factor receptor (EGFR), in a non-small cell lung cancer cell line (H522). Developing highly sensitive Ag NGS nanoprobes that enable multiplex biomolecular detection and imaging can open up new possibilities for point-of-care diagnostics and provide appropriate treatment options and prognosis.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Nanopartículas del Metal/química , Receptor ErbB-2/análisis , Plata/química , Biomarcadores de Tumor/análisis , Línea Celular Tumoral , Receptores ErbB/análisis , Humanos , Nanopartículas del Metal/ultraestructura , Espectrometría Raman/métodos
7.
Int J Nanomedicine ; 16: 941-950, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33603361

RESUMEN

Purpose: Candidemia infection is common in the clinic and has a high mortality rate. Candida albicans, Candida tropicalis, and Candida krusei are very important and common pathogenic species. Candida is difficult to isolate from clinical samples and culture, and immunological detection cannot distinguish these related strains. Furthermore, Candida has a complex cell wall, which causes difficulties in the extraction of DNA for nucleic acid detection. The purpose of this study was to establish a protocol for the direct identification of Candida from serum. Materials and Methods: We synthesized Fe3O4@PEI (where PEI stands for polyethylenimine) magnetic nanoparticles to capture Candida and prepared positively charged silver nanoparticles (AgNPs+) as the substrate for surface-enhanced Raman scattering (SERS). Candida was directly identified from serum by SERS detection. Results: Orthogonal partial least squares discriminant analysis (OPLS-DA) was used as the multivariate analysis tool. Principal component analysis confirmed that this method can clearly distinguish common Candida. After 10-fold cross-validation, the accuracy of training data in this model was 100% and the accuracy of test data was 99.8%, indicating that the model has good classification ability. Conclusion: The detection could be completed within 40 minutes using Fe3O4@PEI and AgNPs+ prepared in advance. This is the first time that Fe3O4@PEI was used in the detection of Candida by SERS. We report the first rapid method to identify fungi directly from serum without breaking the cell wall to extract DNA from the fungi.


Asunto(s)
Candida/aislamiento & purificación , Nanopartículas de Magnetita/química , Nanopartículas del Metal/química , Plata/química , Espectrometría Raman/métodos , Candida albicans , Análisis Discriminante , Humanos , Análisis de los Mínimos Cuadrados , Nanopartículas de Magnetita/ultraestructura , Nanopartículas del Metal/ultraestructura , Análisis Multivariante , Polietileneimina/química
8.
Nat Commun ; 12(1): 1292, 2021 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-33637710

RESUMEN

Surface-enhanced Raman spectroscopy (SERS) has emerged as a powerful tool to detect biomolecules in aqueous environments. However, it is challenging to identify protein structures at low concentrations, especially for the proteins existing in an equilibrium mixture of various conformations. Here, we develop an in situ optical tweezers-coupled Raman spectroscopy to visualize and control the hotspot between two Ag nanoparticle-coated silica beads, generating tunable and reproducible SERS enhancements with single-molecule level sensitivity. This dynamic SERS detection window is placed in a microfluidic flow chamber to detect the passing-by proteins, which precisely characterizes the structures of three globular proteins without perturbation to their native states. Moreover, it directly identifies the structural features of the transient species of alpha-synuclein among its predominant monomers at physiological concentration of 1 µM by reducing the ensemble averaging. Hence, this SERS platform holds the promise to resolve the structural details of dynamic, heterogeneous, and complex biological systems.


Asunto(s)
Pinzas Ópticas , Proteínas/química , Espectrometría Raman/métodos , Nanopartículas del Metal/química , Microfluídica , Muramidasa/química , Proteínas/metabolismo , Dióxido de Silicio/química , Plata/química , Propiedades de Superficie
9.
Food Chem ; 350: 129025, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33609938

RESUMEN

Silver-coated gold nanoparticles (Au@AgNPs) were optimized with different gold (Au) core sizes and modified surface with mercaptooctane (MCO) to determine fungicide residues in pear fruit extracts. The developed MCO/Au@AgNPs with a gold core size of 28 nm and silver shell thickness of 6 nm exhibited high sensitivity and significant enhancement of Raman scattering in detecting tricyclazole (TCZ) and thiram fungicides in standard and pear fruit samples. The detection limits for TCZ and thiram in the pear fruit extracts were 0.005 and 0.003 ppm with coefficients of determination of (R2) of 0.9984 and 0.9971, percent recovery ranging from 82.7 to 107.4% and 80.7 to 109.8%, and relative standard deviation (RSD) of 1.5 to 7.9% and 3.7 to 9.5%, respectively. Results showed that this easily prepared method could be employed as SERS active platforms for the rapid assessment of trace contaminants of agrochemicals in agriculture production.


Asunto(s)
Fungicidas Industriales/análisis , Oro/química , Nanopartículas del Metal/química , Pyrus/química , Plata/química , Tiazoles/química , Tiram/análisis , Límite de Detección , Extractos Vegetales/análisis , Reproducibilidad de los Resultados , Espectrometría Raman/métodos
10.
Nat Commun ; 12(1): 1305, 2021 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-33637723

RESUMEN

Imaging the spatial distribution of biomolecules is at the core of modern biology. The development of fluorescence techniques has enabled researchers to investigate subcellular structures with nanometer precision. However, multiplexed imaging, i.e. observing complex biological networks and interactions, is mainly limited by the fundamental 'spectral crowding' of fluorescent materials. Raman spectroscopy-based methods, on the other hand, have a much greater spectral resolution, but often lack the required sensitivity for practical imaging of biomarkers. Addressing the pressing need for new Raman probes, herein we present a series of Raman-active  nanoparticles (Rdots) that exhibit the combined advantages of ultra-brightness and compact sizes (~20 nm). When coupled with the emerging stimulated Raman scattering (SRS) microscopy, these Rdots are brighter than previously reported Raman-active organic probes by two to three orders of magnitude. We further obtain evidence supporting for SRS imaging of Rdots at single particle level. The compact size and ultra-brightness of Rdots allows immunostaining of specific protein targets (including cytoskeleton and low-abundant surface proteins) in mammalian cells and tissue slices with high imaging contrast. These Rdots thus offer a promising tool for a large range of studies on complex biological networks.


Asunto(s)
Imagen Óptica/métodos , Espectrometría Raman/métodos , Animales , Biomarcadores , Células COS , Chlorocebus aethiops , Citoesqueleto , Células HeLa , Humanos , Microscopía/métodos , Nanopartículas , Imagen Óptica/instrumentación
11.
Nat Commun ; 12(1): 1087, 2021 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-33597530

RESUMEN

The introduction of immune checkpoint inhibitors has demonstrated significant improvements in survival for subsets of cancer patients. However, they carry significant and sometimes life-threatening toxicities. Prompt prediction and monitoring of immune toxicities have the potential to maximise the benefits of immune checkpoint therapy. Herein, we develop a digital nanopillar SERS platform that achieves real-time single cytokine counting and enables dynamic tracking of immune toxicities in cancer patients receiving immune checkpoint inhibitor treatment - broader applications are anticipated in other disease indications. By analysing four prospective cytokine biomarkers that initiate inflammatory responses, the digital nanopillar SERS assay achieves both highly specific and highly sensitive cytokine detection down to attomolar level. Significantly, we report the capability of the assay to longitudinally monitor 10 melanoma patients during immune inhibitor blockade treatment. Here, we show that elevated cytokine concentrations predict for higher risk of developing severe immune toxicities in our pilot cohort of patients.


Asunto(s)
Inmunoterapia/métodos , Melanoma/terapia , Monitorización Inmunológica/métodos , Espectrometría Raman/métodos , Quimiocina CX3CL1/inmunología , Quimiocina CX3CL1/metabolismo , Estudios de Cohortes , Citocinas/inmunología , Citocinas/metabolismo , Factor Estimulante de Colonias de Granulocitos/inmunología , Factor Estimulante de Colonias de Granulocitos/metabolismo , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Humanos , /inmunología , Ipilimumab/efectos adversos , Ipilimumab/inmunología , Ipilimumab/uso terapéutico , Melanoma/inmunología , Melanoma/metabolismo , Microscopía Confocal/métodos , Proyectos Piloto , Reproducibilidad de los Resultados
12.
J Pharm Biomed Anal ; 196: 113924, 2021 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-33581588

RESUMEN

Owing to its simplicity and low cost, the lateral flow assay (LFA) is one of the most commonly used point-of-care diagnostic techniques, despite its low sensitivity and poor quantification. Here, we report a newly developed LFA-NanoSuit method (LNSM) combined with a desktop scanning electron microscope (SEM) for the direct observation of immunocomplexes labeled with a colloidal metal instead of signal enhancement strategies, such as using color, electrochemical signals, silver enhancement, magnetic properties, luminescent, and surface-enhanced Raman spectroscopy (SERS). The proposed LNSM suppresses cellulose deformity, thereby allowing the acquisition of high-resolution images of gold/platinum-labeled immunocomplexed pathogens such as influenza A, without conductive treatment as in conventional SEM. Electron microscopy-based diagnosis of influenza A exhibited 94 % clinical sensitivity (29/31; 95 % confidence interval [CI]: 79.3-98.2 %) and 100 % clinical specificity (95 % CI: 98.1-100 %), which was more sensitive (71.4 %) than visual detection (14.3 %), especially in the lower influenza A-RNA copy number group. The detection ability of our method was nearly comparable to that of real-time reverse transcription-PCR. This is the first report on the diagnosis of clinical diseases using LFA equipped with a desktop SEM. This simple and highly sensitive quantitative analysis method involving LFA can be used to diagnose various diseases in humans and livestock, including highly infectious diseases such as COVID-19.


Asunto(s)
Bioensayo/métodos , Oro/química , Nanopartículas del Metal/química , Microscopía Electrónica de Rastreo/métodos , Platino (Metal)/química , Animales , Estudios de Evaluación como Asunto , Humanos , Límite de Detección , Ganado , Pruebas en el Punto de Atención , Espectrometría Raman/métodos
13.
Nat Commun ; 12(1): 159, 2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33420035

RESUMEN

The quantitative label-free detection of neurotransmitters provides critical clues in understanding neurological functions or disorders. However, the identification of neurotransmitters remains challenging for surface-enhanced Raman spectroscopy (SERS) due to the presence of noise. Here, we report spread spectrum SERS (ss-SERS) detection for the rapid quantification of neurotransmitters at the attomolar level by encoding excited light and decoding SERS signals with peak autocorrelation and near-zero cross-correlation. Compared to conventional SERS measurements, the experimental result of ss-SERS shows an exceptional improvement in the signal-to-noise ratio of more than three orders of magnitude, thus achieving a high temporal resolution of over one hundred times. The ss-SERS measurement further allows the attomolar SERS detection of dopamine, serotonin, acetylcholine, γ-aminobutyric acid, and glutamate without Raman reporters. This approach opens up opportunities not only for investigating the early diagnostics of neurological disorders or highly sensitive biomedical SERS applications but also for developing low-cost spectroscopic biosensing applications.


Asunto(s)
Técnicas Biosensibles/métodos , Neurotransmisores/análisis , Espectrometría Raman/métodos , Estudios de Factibilidad , Oro/química , Nanopartículas del Metal/química
14.
Food Chem ; 347: 129023, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33484959

RESUMEN

This study developed a novel surface-enhanced Raman spectroscopy (SERS) method coupled with cellulose nanofiber (CNF)-based SERS wipers that were fabricated on quartz papers coated with a mixture of silver nanoparticle (AgNP) and gold nanostar (AuNS). A "drop-wipe-test" protocol was developed for rapid detection of pesticide residues in vegetables by SERS. Tremendously enhanced Raman scattering signals were obtained from the quartz/CNF/mixture (AgNP + AuNS) substrate, which were much higher than the paper/mixture (AgNP + AuNS) substrate. This method was used to detect ferbam on kale leaves within a few minutes and the detection limit was 50 µg/kg based on the PLS models (R2 = 0.89). The enhancement factor of the SERS substrate was calculated to be ~ 104 with satisfactory reproducibility. Satisfactory SERS performance could be achieved within 1-month storage period. These results demonstrate that this CNF-based SERS/wiper method is a practical approach for rapid detection of chemical contaminants in fresh produce.


Asunto(s)
Brassica/química , Dimetilditiocarbamato/análisis , Nanopartículas del Metal/química , Nanofibras/química , Espectrometría Raman/métodos , Celulosa/química , Oro/química , Residuos de Plaguicidas/análisis , Reproducibilidad de los Resultados , Plata/química
15.
Int J Mol Sci ; 22(2)2021 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-33466869

RESUMEN

Raman spectroscopy (RS), a non-invasive and label-free method, has been suggested to improve accuracy of cytological and even histopathological diagnosis. To our knowledge, this novel technique tends to be employed without concrete knowledge of molecular changes in cells. Therefore, identification of Raman spectral markers for objective diagnosis is necessary for universal adoption of RS. As a model study, we investigated human mammary epithelial cells (HMEpC) and breast cancer cells (MCF-7) by RS and employed various multivariate analyses (MA) including principal components analysis (PCA), linear discriminant analysis (LDA), and support vector machine (SVM) to estimate diagnostic accuracy. Furthermore, to elucidate the underlying molecular changes in cancer cells, we utilized multivariate curve resolution analysis-alternating least squares (MCR-ALS) with non-negative constraints to extract physically meaningful spectra from complex cellular data. Unsupervised PCA and supervised MA, such as LDA and SVM, classified HMEpC and MCF-7 fairly well with high accuracy but without revealing molecular basis. Employing MCR-ALS analysis we identified five pure biomolecular spectra comprising DNA, proteins and three independent unsaturated lipid components. Relative abundance of lipid 1 seems to be strictly regulated between the two groups of cells and could be the basis for excellent discrimination by chemometrics-assisted RS. It was unambiguously assigned to linoleate rich glyceride and therefore serves as a Raman spectral marker for reliable diagnosis. This study successfully identified Raman spectral markers and demonstrated the potential of RS to become an excellent cytodiagnostic tool that can both accurately and objectively discriminates breast cancer from normal cells.


Asunto(s)
Neoplasias de la Mama/metabolismo , Mama/metabolismo , Células Epiteliales/metabolismo , Espectrometría Raman/métodos , Biomarcadores de Tumor/análisis , Mama/citología , Neoplasias de la Mama/diagnóstico , Análisis Discriminante , Glicéridos/análisis , Humanos , Análisis de los Mínimos Cuadrados , Ácido Linoleico/análisis , Células MCF-7 , Análisis Multivariante , Análisis de Componente Principal , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Máquina de Vectores de Soporte
17.
Anal Chem ; 93(4): 2183-2190, 2021 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-33410673

RESUMEN

Monitoring externalization of phosphatidylserine (PS) and gaining insights into molecular events of cell membrane damage are significant for programmed cell death studies. Herein, by encapsulating zeolitic imidazole frameworks-8 with plasmonic gold nanoparticles to form micron-nano composites and using them as a single-particle surface-enhanced Raman spectroscopy (SERS) substrate, we succeeded in real-time discriminating and monitoring the externalization of PS on cell membranes during electrostimulus-induced apoptosis. The micron-nano composite probe provides rich "hot spots" and robust anchoring capacity for cell membranes, achieving the capture and label-free single-particle SERS detection of the externalized PS. By this method, the dynamic PS externalization process differences between cancerous cells and normal cells were clearly revealed of which the cell membrane damage of cancerous cells was more serious than that of normal cells. This method is versatile and robust for monitoring the externalization of PS and uncovering related cell membrane damage mechanisms. This work also broadens the application of metal-organic framework materials for advanced biomedical applications.


Asunto(s)
Membrana Celular/química , Nanopartículas del Metal/química , Fosfatidilserinas/química , Imagen Individual de Molécula/métodos , Espectrometría Raman/métodos , Línea Celular Tumoral , Oro/química , Humanos , Imidazoles/química , Nanocompuestos , Fosfatidilserinas/metabolismo , Rodaminas , Propiedades de Superficie
18.
Anal Chem ; 93(4): 2125-2134, 2021 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-33435684

RESUMEN

To profile the metabolic dynamics responding to drugs at the single-cell/organelle resolution, rapid and economical mechanism-revealing methods are required. Here, we introduced D2O-probed Raman microspectroscopy in combination with the multivariate curve resolution-alternating least squares (MCR-ALS or MCR) algorithm. Exploiting MCR to deconvolute each macromolecular component specifically, the method is able to track and distinguish changes in lipid and protein metabolic activities in a human cancer cell line (MCF-7) and in Saccharomyces cerevisiae, in response to the metabolism-inhibitory effect of rapamycin, which inhibits the mammalian/mechanistic target of rapamycin (mTOR) signaling. Under rapamycin, in the lipid bodies of cancer cells, metabolic activities of both protein and lipid are suppressed; in the nucleus, protein synthesis remains active, whereas lipid synthesis is inhibited; in the cytoplasm, syntheses of protein and lipid are both dose- and duration-dependent. Thus, rapamycin differentially influences protein and lipid synthesis in mTOR signaling. Moreover, the strong correlation between macromolecular-specific components of yeast and those in MCF-7 cytoplasm, nucleus, and lipid bodies revealed similarity in rapamycin response. Notably, highly metabolically active cancer cells after high-dosage rapamycin exposure (500 or 5000 × IC50) were revealed, which escape detection by population-level cytotoxicity tests. Thus, by unveiling macromolecule-specific metabolic dynamics at the organelle level, the method is valuable to mechanism-based rapid screening and dissection of drug response.


Asunto(s)
Antineoplásicos/farmacología , Óxido de Deuterio , Sustancias Macromoleculares/metabolismo , Orgánulos/efectos de los fármacos , Sirolimus/farmacología , Espectrometría Raman/métodos , Antibióticos Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células MCF-7 , Orgánulos/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos
19.
J Environ Sci Health B ; 56(3): 222-234, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33417510

RESUMEN

Surface-enhanced Raman scattering (SERS) is a promising technique for rapid detection of pesticide residues. However, conventional SERS substrates require extraction processes which are time consuming and they also lack selectivity, stability and reproducibility. Herein, we present a multifunctional stable zero-valent iron based core-shell substrate. It combines magnetic separation, selective adsorption by molecular imprinting technique and sensitive detection of carbaryl by SERS. The core-shell substrate was successfully prepared by immobilizing silver on the surface of zero-valent iron microspheres. Subsequent molecular imprinting on the bimetallic magnetic silver microspheres ensured selective removal and detection. The substrate exhibited magnetization saturation of 8.89 emu/g providing efficient analyte separation. It showed high sensitivity and selectivity toward carbaryl detection to nanomolar concentration level. Linear regression models for peaks at Raman shift 1599 cm-1 and 2233 cm-1 demonstrated a good linear fit with R2=0.9738 and R2=0.8952 respectively. The composite was successfully applied on spiked water samples resulting in average recovery rate of 89%. The findings of this study demonstrate great substrate potential for application in separation and detection of trace quantities of chemical contaminants for environment safety and protection.


Asunto(s)
Carbaril/análisis , Nanopartículas del Metal/química , Residuos de Plaguicidas/análisis , Espectrometría Raman/métodos , Contaminantes Químicos del Agua/análisis , Adsorción , Hierro/química , Fenómenos Magnéticos , Microesferas , Impresión Molecular/métodos , Oxidación-Reducción , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Plata/química
20.
Commun Biol ; 4(1): 70, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33452375

RESUMEN

The proliferation and transmission of viruses has become a threat to worldwide biosecurity, as exemplified by the current COVID-19 pandemic. Early diagnosis of viral infection and disease control have always been critical. Virus detection can be achieved based on various plasmonic phenomena, including propagating surface plasmon resonance (SPR), localized SPR, surface-enhanced Raman scattering, surface-enhanced fluorescence and surface-enhanced infrared absorption spectroscopy. The present review covers all available information on plasmonic-based virus detection, and collected data on these sensors based on several parameters. These data will assist the audience in advancing research and development of a new generation of versatile virus biosensors.


Asunto(s)
/diagnóstico , Pandemias , Espectrometría Raman/métodos , Resonancia por Plasmón de Superficie/métodos , /virología , Humanos , Nanoestructuras/química , Espectrometría de Fluorescencia/métodos , Espectrofotometría Infrarroja/métodos
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