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1.
Anal Chem ; 93(36): 12329-12336, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34474564

RESUMO

"On-demand" accurate imaging of multiple intracellular miRNAs will significantly improve the detection reliability and accuracy. However, the "always-active" design of traditional multicomponent detection probes enables them to passively recognize and output signals as soon as they encounter targets, which will inevitably impair the detection accuracy and, inevitably, result in false-positive signals. To address this scientific problem, in this work, we developed a near-infrared (NIR) light-activated multicomponent detection intelligent nanoprobe for spatially and temporally controlled on-demand accurate imaging of multiple intracellular miRNAs. The proposed intelligent nanoprobe is composed of a rationally designed UV light-responsive triangular DNA nano sucker (TDS) and upconversion nanoparticles (UCNPs), named UCNPs@TDS (UTDS), which can enter cells autonomously through endocytosis and enable remote regulation of on-demand accurate imaging for multiple intracellular miRNAs using NIR light illumination at a chosen time and place. It is worth noting that the most important highlight of the UTDS we designed in this work is that it can resist nonspecific activation as well as effectively avoid false-positive signals and improve the accuracy of imaging of multiple intracellular miRNAs. Moreover, distinguishing different kinds of cell lines with different miRNA expressions levels can be also achieved through this NIR light-activated intelligent UTDS, showing feasible prospects in precise imaging and disease diagnosis.


Assuntos
MicroRNAs , Nanopartículas , DNA , Raios Infravermelhos , Reprodutibilidade dos Testes
2.
World J Clin Cases ; 9(4): 976-982, 2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33585647

RESUMO

BACKGROUND: Squamous cell carcinoma (SCC) of bone is usually caused by metastasis from the lungs, bladder, or other sites. Primary SCC of bone most frequently involves the skull bones, and primary involvement of other sites in the skeletal system is extremely rare. To date, only three such cases have been reported, which makes the diagnosis, treatment, and prognosis of this disease a challenge. CASE SUMMARY: A 76-year-old Chinese man presented to our hospital with nonspecific pain and limited mobility in the right shoulder for 4 mo. He underwent three-dimensional computed tomography reconstruction and magnetic resonance imaging of the right shoulder, which revealed an osteolytic destructive lesion in the right scapula with invasion into the surrounding muscles and soft tissues. Ultrasound-guided core needle biopsy detected a malignant tumor, and immunohistochemical analysis revealed a poorly differentiated SCC. Wide excision of the right scapular bone was performed, and pathological examination of the surgical specimen confirmed the diagnosis. At the last follow-up examination within 2 years, the patient was doing well with the pain significantly relieved in the right shoulder. CONCLUSION: Primary SCC of bone is extremely rare at sites other than the skull. Clinicians must exhaust all available means for the diagnosis of primary SCC of the bone, so greater attention can be paid to its timely and effective management. Regular and adequate follow-up is essential to help rule out metastasis and judge the prognosis.

3.
Anal Chem ; 93(4): 2480-2489, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33410672

RESUMO

Plasmon-enhanced fluorescence (PEF) is considered to be a powerful signal amplification technology to overcome intrinsic shortcomings of photobleaching and brightness of the traditional fluorescent dyes. Nevertheless, exploitation of PEF-based probes for bioimaging application is still at a very early stage. In this work, a simple but powerful gold nanostar (Au NST)@SiO2-based PEF probe with 20 symmetric "hot spots" was developed for highly sensitive "lighting up" in situ imaging of intracellular microRNAs (miRNAs). By regulating the thickness of the silica shell, the distance between Au NSTs and fluorescent dyes was controlled, and the optimum fluorescence enhancement (21-fold) was obtained with the silica shell thickness of approximately 22 nm. Thanks to the 20 more powerful "hot spots" that can produce stronger localized electric fields, the Au NST-based PEF probe exhibits stronger PEF effects than the traditional plasmonic nanostructures such as gold nanorods (Au NRs), gold nanobipyramids (Au NBPs), and triangular gold nanoprisms (Au NPRs), resulting in high sensitivity and improved detection limit (LOD) of 0.21 pM for miRNA-21 analysis. Moreover, not only cancer cells (MCF-7 and Hela) and normal cells (L02) with distinct miRNA-21 expression levels can be discriminated but also tumor cells in co-cultured mixtures can be recognized, indicating its promising potential in clinical diagnosis.

4.
Anal Chem ; 92(22): 15169-15178, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33125850

RESUMO

Versatile all-in-one nanoplatforms that inherently possess both diagnostic imaging and therapeutic capabilities are highly desirable for efficient tumor diagnosis and treatment. Herein, we have developed a novel core-shell multifunctional nanomaterial-based all-in-one nanoplatform composed of gold nanobipyramids@polydopamine (Au NBPs@PDA) and gold nanoclusters (Au NCs) for simultaneous in situ multilayer imaging of dual types of tumor biomarkers (using a single-wavelength excitation) with different intracellular spatial distributions and fluorescence-guided photothermal therapy. The competitive combination between target transmembrane glycoprotein mucin1 (MUC1) and its aptamer caused Au NCs (620 nm) labeled with MUC1 aptamer to detach from the surface of Au NBPs@PDA, turning on the red fluorescence. Meanwhile, the hybridization between microRNA-21 (miRNA-21) and its complementary single-stranded DNA triggered the green fluorescence of Au NCs (515 nm). Based on this, simultaneous in situ multilayer imaging of dual types of tumor biomarkers with different intracellular spatial distributions was achieved. In addition, the potential of Au NBPs@PDA/Au NCs was also confirmed by simultaneous multilayer in situ imaging within not only three cell lines (MCF-7, HepG2, and L02 cells) with different expression levels of MUC1 and miRNA-21 but also cancer cells treated with different inhibitors. Moreover, the remarkable photothermal properties of Au NBPs@PDA resulted in the more efficient killing of cancer cells, demonstrating the great promise of the all-in-one nanoplatform for accurate diagnosis and tumor therapy.


Assuntos
Biomarcadores Tumorais/metabolismo , Imagem Molecular/métodos , Nanoestruturas/química , Fototerapia , Nanomedicina Teranóstica/métodos , Linhagem Celular Tumoral , Humanos
5.
Chem Commun (Camb) ; 56(89): 13828-13831, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33079123

RESUMO

Based on the distinct fingerprint-like fluorescence responses generated by different electrostatic and hydrophobic interactions between three kinds of self-designed water-soluble aggregation-induced emission (AIE) fluorogens (AIEgens) and proteins, a fast responsive (10 min) and one-step "lighting up" fluorescent sensor array for rapid protein discrimination was developed.


Assuntos
Proteínas/química , Técnicas Biossensoriais , Fluorescência , Corantes Fluorescentes/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Solubilidade , Espectrometria de Fluorescência , Água
6.
Chem Commun (Camb) ; 56(29): 4074-4077, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32159543

RESUMO

In this study, three kinds of CDs with blue, yellow and red emissions were prepared and their luminescence mechanisms through theoretical calculations together with experimental data were further investigated in depth. Afterwards, a sensor array was constructed by using three kinds of CD-metal ions for rapid discrimination of different types of sulfur-containing species.

7.
Comput Methods Programs Biomed ; 187: 105236, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31786452

RESUMO

BACKGROUND AND OBJECTIVE: Videocapsule endoscopy (VCE) is a relatively new technique for evaluating the presence of villous atrophy in celiac disease patients. The diagnostic analysis of video frames is currently time-consuming and tedious. Recently, computer-aided diagnosis (CAD) systems have become an attractive research area for diagnosing celiac disease. However, the images captured from VCE are susceptible to alterations in light illumination, rotation direction, and intestinal secretions. Moreover, textural features of the mucosal villi obtained by VCE are difficult to characterize and extract. This work aims to find a novel deep learning feature learning module to assist in the diagnosis of celiac disease. METHODS: In this manuscript, we propose a novel deep learning recalibration module which shows significant gain in diagnosing celiac disease. In this recalibration module, the block-wise recalibration component is newly employed to capture the most salient feature in the local channel feature map. This learning module was embedded into ResNet50, Inception-v3 to diagnose celiac disease using a 10-time 10-fold cross-validation based upon analysis of VCE images. In addition, we employed model weights to extract feature points from training and test samples before the last fully connected layer, and then input to a support vector machine (SVM), k-nearest neighbor (KNN), and linear discriminant analysis (LDA) for differentiating celiac disease images from heathy controls. RESULTS: Overall, the accuracy, sensitivity and specificity of the 10-time 10-fold cross-validation were 95.94%, 97.20% and 95.63%, respectively. CONCLUSIONS: A novel deep learning recalibration module, with global response and local salient factors is proposed, and it has a high potential for utilizing deep learning networks to diagnose celiac disease using VCE images.


Assuntos
Doença Celíaca/diagnóstico por imagem , Aprendizado Profundo , Diagnóstico por Computador/métodos , Endoscopia , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Calibragem , Endoscopia por Cápsula , Análise Discriminante , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Mucosa Intestinal/diagnóstico por imagem , Luz , Modelos Lineares , Aprendizado de Máquina , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Máquina de Vetores de Suporte , Gravação em Vídeo
8.
ACS Appl Mater Interfaces ; 12(1): 373-379, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31840494

RESUMO

A simple and label-free sensing platform with low background based on the chain-displacement triggered self-assembly of Ag NCs was developed for ratiometric visual analysis of intracellular miRNA-21. Based on this sensitively ratiometric sensing approach, a picomole limit detection for miRNA-21 can be obtained. Most importantly, compared with the traditional single base mismatch detection method, our proposed method can realize single base mismatch detection according to the remarkable fluorescence color conversion, rather than simple fluorescence intensity change, which can obviously improve the accuracy and reliability. In addition, successful multicolor real-time monitoring of intracellular miRNA-21 makes the probe a potential candidate for miRNA-21 inhibiting drug screening. Furthermore, MCF-7, HeLa, and normal L02 cells can also be visually differentiated according to the fluorescence color by using the label-free sensing platform, showing its potential prospect in target visual analysis.


Assuntos
Nanopartículas Metálicas/química , Nanoestruturas/química , Ácidos Nucleicos/química , Prata/química , Técnicas Biossensoriais/métodos , Células HeLa , Humanos , Células MCF-7 , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão
9.
Anal Chem ; 91(21): 13947-13952, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31558029

RESUMO

Gold nanoclusters (Au NCs) coated with various peptides have been widely used as fluorescent probes, and nowadays the most commonly used are cysteine (C) and tyrosine (Y) based ones. Herein, we report the preparation and clinical application of highly efficient and stable fluorescent Au NCs protected by screened peptides with a specific amino acid sequence Cys-Met-Met-Met-Met-Met (CMMMMM). Compared with traditional C, Y based peptide (CYYYYY) protected Au NCs, the fluorescence intensity of the CMMMMM-Au NCs increased by 230%, and the photobleaching resistance or stability of the CMMMMM-Au NCs increased by about 300% (after continuous ultraviolet irradiation for 60 min, the fluorescence of the CMMMMM-Au NCs remained more than 90% of their initial intensity, while the CYYYYY-Au NCs remained less than 30%). Assaying arrays based on CMMMMM protected Au NCs with different positive or negative charges as sensing receptors were developed through regulating different pH values, and multivariate analysis on the patterns obtained by these arrays allowed effective identification of not only ten proteins separately but also complex protein mixtures with subtly diverse compositions. The docking simulation and isothermal titration confirmed that target proteins interacted with CMMMMM-Au NCs mainly through electrostatic interactions and partly hydrophobic interactions, which affected the binding energy and fluorescence lifetime of CMMMMM-Au NCs, resulting in the unique fingerprint-like recognition patterns. Furthermore, serums from breast cancer, severe osteoarthritis, and rectal cancer patients can be effectively identified with healthy people using this CMMMMM-Au NCs based sensor array.


Assuntos
Ouro , Nanopartículas Metálicas/química , Peptídeos/química , Sequência de Aminoácidos , Neoplasias da Mama/diagnóstico , Corantes Fluorescentes/química , Osteoartrite/diagnóstico , Fotodegradação , Proteômica/métodos , Neoplasias Retais/diagnóstico , Eletricidade Estática
10.
Analyst ; 144(20): 6019-6024, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31538152

RESUMO

With the increase in cancer risk, early immunodiagnosis is of great significance for timely therapy. In this work, a DNA-mediated immunosensor for the highly sensitive detection of prostate specific antigen (PSA) is proposed, which is mainly based on a portable personal glucose meter (PGM). Gold nanoparticles (AuNPs) functionalized with PSA detection antibodies and DNA primers are introduced. When the target of the PSA is present, rolling circle amplification (RCA) reactions on AuNPs are triggered and numerous repeated RCA products hybridize with the DNA-conjugated invertase; thus the signal of the PGM is generated and the PSA is quantified indirectly. With the use of a portable PGM, our method realizes a linear detection range of 0.003-50 ng mL-1, with a low detection limit of 0.1 pg mL-1, which is comparable to that of the traditional methods using expensive apparatus. Besides, the analysis of clinical human serum samples is performed to investigate its good practicability. This simple, low-cost, and miniaturized immunosensor is promising for the point-of-care testing of cancer markers.


Assuntos
Anticorpos Imobilizados/química , Técnicas Biossensoriais/métodos , DNA/química , Ouro/química , Nanopartículas Metálicas/química , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Humanos , Imunoensaio , Limite de Detecção , Masculino , Neoplasias da Próstata/sangue
11.
Anal Chim Acta ; 1079: 192-199, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387710

RESUMO

Herein, a zinc ion (Zn2+)-triggered aggregation induced emission enhancement (AIEE) fluorescence "on-off-on" nanoswitch was fabricated for inorganic pyrophosphate (PPi) and inorganic pyrophosphatase (PPase) activity detection. Dual ligand functionalized Au NCs were utilized as the substrate of the AIEE nanoswitch. The introduction of Zn2+ can cause Au NCs aggregated along with the enhanced fluorescence. After the addition of PPi, aggregated Au NCs disaggregated along with decreased fluorescence due to the competitive combination between PPi and Zn2+ (on-off). When PPase was introduced, PPi was hydrolyzed and release Zn2+, resulting in aggregated Au NCs along with enhanced fluorescence again (off-on). On the basis of this, highly selective and sensitive detection PPi (liner range from 0.1 to 300 µM) and PPase activity (liner range from 0.1 to 10 mU) can be achieved. The detection limits are 0.04 µM for PPi and 0.03 mU for PPase, respectively. Furthermore, the as-prepared Zn2+-triggered AIEE nanoswitch was successfully used for quantitative analysis of PPase activity in human serum with satisfactory spiked recoveries, and applied for the inhibitors screening.


Assuntos
Difosfatos/sangue , Pirofosfatase Inorgânica/sangue , Nanopartículas Metálicas/química , Zinco/química , Ensaios Enzimáticos/métodos , Fluorescência , Ouro/química , Humanos , Limite de Detecção , Espectrometria de Fluorescência/métodos
12.
Mikrochim Acta ; 186(7): 447, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197573

RESUMO

A sensitive and rapid fluorometric "switch on" assay is described for the detection of microRNA-21. It is based on the use of a fluorescence resonance energy transfer pair consisting of lysozyme-modified gold nanoclusters (Lys-Au NCs) and carbon nanotubes (CNTs). The Lys-Au NCs can be synthesized by a microwave-assisted technique within 2.5 min. They were modified with the ss-DNA probe (a 22-mer) for microRNA-21. Once the ss-DNA associates with the CNTs due to π stacking, the orange-red fluorescence (with excitation/emission peaks at 500/610 nm) is quenched. Nevertheless, the quenched fluorescence can be recovered after addition of microRNA-21 because of the stronger affnity between ss-DNA and microRNA-21. On the basis of the fluorescence recovery at 610 nm caused by microRNA-21, the latter can be quantified in the 0.01 to 100 nM concentration range, with a 36 pM detection limit. The method was applied to the determination of microRNA-21 in spiked serum with recoveries ranging from 98.6% to 110.0%. It also enables normal and cancer cells to be differentiated by direct imaging of intracellular microRNA-21. Graphical abstract A sensitive "switch on" FRET-based fluorometric assay for microRNA-21 is described. It is based on the use of  lysozyme-modified gold nanoclusters (Lys-Au NCs) and carbon nanotubes (CNTs) as energy donor and energy acceptor, respectively.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Nanopartículas Metálicas/química , MicroRNAs/sangue , Nanotubos de Carbono/química , Ouro/química , Humanos , Limite de Detecção , Microscopia de Fluorescência/métodos
13.
Anal Chim Acta ; 1071: 53-58, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31128755

RESUMO

An ultrasensitively multicolor colorimetric assay on the basis of enzyme-catalyzed reaction mediated etching of gold nanobipyramids (Au NBPs) is developed for detection of blood glucose with naked eye. This assay depends on the catalytic oxidation of H2O2 (generated from glucose oxidation) by horseradish peroxidase (HRP) to generate hydroxyl radicals (•OH) with strong oxidizability, which can accelerate the Au NBPs etching and accompany with vivid color changes and localized surface plasmon resonance (LSPR) blue shift. On the basis of this, the proposed colorimetric glucose assay accomplishes a dynamic range of 0.05-90 µM with detection limit of 0.02 µM, which is almost three orders of magnitude lower than that (10 µM) based on gold nanorods (Au NRs). Moreover, the approximate glucose levels can be intuitively and conveniently judged by the color changes with naked eye. Most importantly, visually distinguish between healthy people and diabetic patients by naked eye dispense with any sophisticated instrument is the most important highlight of this colorimetric assay, indicating the available potential for diagnosis. To the best of our knowledge, this is the first report of colorimetric assay using Au NBPs as etching substrates for visually analysis of glucose.


Assuntos
Glicemia/análise , Colorimetria/métodos , Ouro/química , Nanopartículas Metálicas/química , Armoracia/enzimologia , Glicemia/química , Cor , Diabetes Mellitus/sangue , Glucose Oxidase/química , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Oxirredução , Propriedades de Superfície
14.
ACS Sens ; 4(4): 938-943, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30864786

RESUMO

Highly sensitive analysis of cancer biomarkers demonstrates an important impact in early diagnosis and therapies of cancer. A novel surface-enhanced Raman scattering (SERS) based immunoassay using microfluidic technique was reported for rapid analysis of prostate-specific antigen (PSA) biomarker. It is a useful screening test to discriminate prostate cancer and other diseases related to prostate. A "sandwich" immunoassay based on SERS nanotags, PSA biomarkers, and magnetic beads was applied on a pump-free microfluidic sensor. Magnetic immunocomplexes are isolated and trapped at the detection chamber by a permanent magnet integrated into the chip. The PBS buffer washed magnetic immunocomplexes and brought the free gold nanoparticles to the downsteam channel for waste. Our results show a good linear response in the range from 0.01 to 100 ng mL-1. The limit of detection of the PSA level is estimated to be below 0.01 ng mL-1 using this chip. This detection level of PSA biomarker in human serum can be accomplished in 5 min without manual incubation and a heavy syringe pump. To the best of our knowledge, this is the first SERS-based immunoassay which applied a pump-free microfluidic chip as a detection platform. We believe that the proposed method reveals a valuable potential tool for the diagnosis of prostate cancer.


Assuntos
Biomarcadores Tumorais/sangue , Imunoensaio/métodos , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/métodos , Antígeno Prostático Específico/sangue , Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/imunologia , Desenho de Equipamento , Humanos , Separação Imunomagnética/métodos , Limite de Detecção , Masculino , Técnicas Analíticas Microfluídicas/instrumentação , Antígeno Prostático Específico/imunologia , Neoplasias da Próstata/diagnóstico , Análise Espectral Raman/métodos
15.
Biomolecules ; 9(2)2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30678100

RESUMO

Tobacco mosaic virus (TMV) is a common source of biological stress that significantly affects plant growth and development. It is also useful as a model in studies designed to clarify the mechanisms involved in plant viral disease. Plant responses to abiotic stress were recently reported to be regulated by complex mechanisms at the post-translational modification (PTM) level. Protein phosphorylation is one of the most widespread and major PTMs in organisms. Using immobilized metal ion affinity chromatography (IMAC) enrichment, high-pH C18 chromatography fraction, and high-accuracy mass spectrometry (MS), a set of proteins and phosphopeptides in both TMV-infected tobacco and control tobacco were identified. A total of 4905 proteins and 3998 phosphopeptides with 3063 phosphorylation sites were identified. These 3998 phosphopeptides were assigned to 1311 phosphoproteins, as some proteins carried multiple phosphorylation sites. Among them, 530 proteins and 337 phosphopeptides corresponding to 277 phosphoproteins differed between the two groups. There were 43 upregulated phosphoproteins, including phosphoglycerate kinase, pyruvate phosphate dikinase, protein phosphatase 2C, and serine/threonine protein kinase. To the best of our knowledge, this is the first phosphoproteomic analysis of leaves from a tobacco cultivar, K326. The results of this study advance our understanding of tobacco development and TMV action at the protein phosphorylation level.


Assuntos
Proteômica , Vírus do Mosaico do Tabaco/química , Tabaco/química , Cromatografia de Afinidade , Fosforilação , Tabaco/metabolismo , Tabaco/virologia , Vírus do Mosaico do Tabaco/isolamento & purificação , Vírus do Mosaico do Tabaco/metabolismo
16.
Colloids Surf B Biointerfaces ; 173: 478-485, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30326364

RESUMO

Alzheimer's disease (AD) is a common neurodegenerative disorder in elderly people, and is associated with a heavy financial burden on our society. The use of serologic biomarkers is an attractive method to diagnose AD. Although the determination of blood-based biomarkers for AD has been explored in many studies, few practical diagnosis methods have been used in the clinic. In this work, we constructed a "chemical tongue" sensor array that is easy to use and based on four kinds of fluorescent gold nanoclusters (Au NCs) for discriminating between multiple proteins at nanomolar concentrations. The device utilizes a linear discrimination analysis based on fluorescence intensity response patterns. Using this chemical tongue sensor array, multiple proteins can be confidently identified even in complex biological systems, such as human urine. Most importantly, sera of AD patients could be effectively discriminated from those of osteoarthritis patients, or of healthy people. Also, the results obtained for the AD patients by the chemical tongue sensor array were validated by CSF determination. We conclude that the chemical tongue sensor array manufactured in this work paves the way for designing an auxiliary diagnosis method for AD that is less invasive and more convenient for the large-scale screening of patients.


Assuntos
Doença de Alzheimer/diagnóstico , Técnicas Biossensoriais , Proteínas Sanguíneas/análise , Ouro/química , Nanopartículas Metálicas/química , Osteoartrite/diagnóstico , Análise Serial de Proteínas/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/fisiopatologia , Biomarcadores/sangue , Estudos de Casos e Controles , Diagnóstico Diferencial , Ácidos Graxos/química , Feminino , Fluorescência , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/sangue , Osteoartrite/fisiopatologia , Análise Serial de Proteínas/instrumentação , Espectrometria de Fluorescência , Compostos de Sulfidrila/química
17.
ACS Appl Mater Interfaces ; 10(50): 43472-43481, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-30480991

RESUMO

The simple, sensitive, and specific detection of hydrogen sulfide (H2S) is of great importance because of its crucial role in food safety, environmental pollution, and various pathological and physiological processes. Here, we reported activatable fluorescence nanoprobe-based quantum dots (QDs) for sensitive and selective monitoring of H2S in red wine, environmental water samples, and lysosome of live cancer cells. The nanoprobe was prepared through a strong electrostatic interaction between thioglycolic-acid-stabilized CdTe QDs and p-amino thiophenol capped silver nanoparticles (AgNPs) that resulted in the formation of the assembled nanostructure, called QD/AgNP nanocomplexes. The initial fluorescence of QDs was effectively quenched by the AgNPs because of the inner filter effect. Upon interaction with H2S, the strong etching ability of H2S to AgNPs could trigger the disassembly of QD/AgNP nanocomplexes and generate Ag2S on the surface of QDs, achieving a shell-core Ag2S/CdTe QDs with remarkable fluorescence as a result of the termination of inner filter effect. The aqueous solution studies displayed that the assembled QD/AgNP nanoprobe was sensitive to detect H2S, with a detection limit of 15 nM. In addition, this assembled QD/AgNP nanoprobe showed a high specificity toward H2S over other anions and biologically relevant species. The subsequent fluorescence imaging studies demonstrated that the assembled QD/AgNP nanoprobe exhibited high ability to enter into cellular lysosome and generated an enhancement fluorescence, which was used for endogenous H2S detection in lysosome of living cancer cells. This proposed nanoprobe revealed a more simple, rapid, time-saving, low-cost, sensitive, and selective process for monitoring of H2S in further environmental pollution, food safety, and clinical diagnosis of H2S-related diseases.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Lisossomos/metabolismo , Nanopartículas Metálicas/química , Pontos Quânticos/química , Prata , Células HeLa , Humanos , Sulfeto de Hidrogênio/análise , Limite de Detecção , Microscopia de Fluorescência , Prata/química , Prata/farmacologia
18.
ACS Appl Mater Interfaces ; 10(32): 26851-26858, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30043605

RESUMO

Herein, we developed a novel plasmon-enhanced fluorescence (PEF)-based telomerase-responsive nanoprobe for in situ fluorescence "turn on" visualization of telomerase activity in live cells. The as-prepared nanoprobe was composed of a nicked molecular beacon (which contains Cy5.5-labeled hairpin-DNA sequences hybridized with telomerase primers)-functionalized gold nanobipyramids (Au NBPs). Au NBPs were selected as both fluorescence resonance energy-transfer and PEF dual-functional substrates, while DNA was selected to be the precise spacer to manage the interval between the Au NBPs and Cy5.5. On the basis of this target-triggered PEF probe, optimal fluorescence enhancement can be obtained with 49 DNA bases, which was higher than gold nanorods. The proposed method accomplishes sensitive telomerase activity detection down to 23 HeLa cells with a dynamic range of 40-1200 HeLa cells. On the basis of this, in situ fluorescence imaging of telomerase activity in live cells and real-time analysis of the variation in intracellular telomerase activity can be achieved. Moreover, cancer cells and normal cells can also be successfully discriminated even in their co-cultured mixtures, indicating promising potential in clinical diagnoses.


Assuntos
Nanoestruturas , Corantes Fluorescentes , Ouro , Células HeLa , Humanos , Nanotubos , Telomerase
19.
Anal Chem ; 90(6): 4039-4045, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29488383

RESUMO

A novel fluorescence resonance energy transfer (FRET)-based platform using polydopamine nanospheres (PDANSs) as energy acceptors and dual colored Au NCs as energy donors for simultaneous detection of multiple tumor-related microRNAs with DNase-I-assisted target recycling amplification was developed for the first time. On the basis of monitoring the change of the recovered fluorescence intensity at 445 and 575 nm upon the addition of targets miRNA-21 and let-7a, these two microRNAs (miRNAs) can be simultaneously quantitatively detected, with detection limits of 4.2 and 3.6 pM (3σ) for miRNA-21 and let-7a, which was almost 20 times lower than that without DNase I. Additionally, semiquantitative determination of miRNA-21 and let-7a can also be realized through photovisualization. Most importantly, serums from normal and breast cancer patients can be visually and directly discriminated without any sample pretreatment by confocal microscope experiments, demonstrating promising potential for auxiliary clinical diagnosis.


Assuntos
Técnicas Biossensoriais/métodos , Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Indóis/química , MicroRNAs/análise , Nanosferas/química , Polímeros/química , Neoplasias da Mama/sangue , Desoxirribonuclease I/química , Feminino , Humanos , MicroRNAs/sangue , Nanosferas/ultraestrutura
20.
Mikrochim Acta ; 185(3): 156, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29594672

RESUMO

An electrochemical biosensor for the detection of microRNA was prepared via chemical grafting of a Methylene Blue labeled reporter (MB-Rep) duplex onto a nanostructured surface that was obtained by electrodeposition of cobalt oxide and poly(o-phenylenediamine). This is followed by the attachment of hyaluronic acid and gold nanoclusters. In the presence of the target (microRNA), the probe-target duplex and the MB-Rep hairpin are formed. These will displace the labeled reporter from the sensor surface, and this results in a decrease of the amperometric signal for MB at a typical working voltage of -0.28 V (vs. Ag/AgCl). The electrode modified with hyaluronic acid possesses a large electroactive surface area and an excellent antifouling property. This makes it useful for ultrasensitive quantitation of microRNA even in complex biological media. The sensor has a linear response in the 100 f. to 0.1 µM microRNA concentration range, and a 33.3 f. detection limit. It was successfully applied to the determination of microRNA in cancer cells. Graphical abstract ᅟ.


Assuntos
Incrustação Biológica , Análise Química do Sangue/métodos , Ouro/química , Ácido Hialurônico/química , Limite de Detecção , Nanopartículas Metálicas/química , MicroRNAs/sangue , Eletroquímica , Humanos , Células MCF-7
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