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Functional nanomaterials have attracted attention by producing different structures in any field. These materials have several potential applications, including medicine, electronics, and energy, which provide many unique properties. These nanostructures can be synthesized using various methods, including self-assembly, which can be used for the same applications. This unique nanomaterial is increasingly being used for biological detection due to its unique optical, electrical, and mechanical properties, which provide sensitive and specific sensors for detecting biomolecules such as DNA, RNA, and proteins. This review highlights recent advances in the field and discusses the fabrication and characterization of the corresponding materials, which can be further applied in optical, magnetic, electronic, and sensor fields.
Assuntos
Técnicas Biossensoriais , Nanoestruturas , Técnicas Biossensoriais/métodos , Nanoestruturas/química , Proteínas , DNA , EletrônicaRESUMO
BACKGROUND: Prostate cancer cells have very high PCA3 messenger RNA levels, which turns them into one of the new biomarkers for prostate cancer prognosis and diagnosis. OBJECTIVE: Our goal here is to develop a new aptasensor to detect PCA3 release by the cancer cell. METHODS: DNA hairpin containing PCA3 aptamer was thiolated, conjugated to methylene blue (MB) redox probe, and immobilized on gold electrode through self-assembly to detect label-free cancer cells. RESULTS: Our data have evidenced stable and sensitive sensors presenting a wide linear detection range (0-150ng/mL). In addition, monitoring PCA3 released by different types of prostate cells can provide in-depth knowledge about prostate cancer dynamics; therefore, it is a powerful platform for earlier clinical diagnostic. The released PCA3 can vary depending on the type of adopted prostate cells. CONCLUSION: PCA3 release was monitored in a group of cells for 2 h; it showed significantly higher expression in both LNCaP and PC-3 cells. This strategy provides a unique and simple methodology to achieve more sensitive and specific PCA3 detection; thus, it emerged as a promising tool for early cost-effective diagnosis.
Assuntos
Aptâmeros de Nucleotídeos , Neoplasias da Próstata , Antígenos de Neoplasias , Biomarcadores Tumorais/genética , DNA , Ouro , Humanos , Masculino , Azul de Metileno , Próstata , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , RNA MensageiroRESUMO
The aim of the current study is to introduce a methodology aimed at producing a biosensor that uses gold nanoparticles (AuNPs) to detect porcine circovirus 2 (PCV-2). This biosensor was based on AuNPs, which were modified with self-assembled monolayers (SAMs) and antibodies. The AuNPs' surface and virus modification process applied to enable antibody binding was accompanied by localized surface plasmon resonance (LSPR), surface plasmon resonance (SPR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Virus quantification was possible by the light absorption difference in the spectrum at concentrations of 105, 106, 107, 108, and 109 DNA copies/mL PCV-2 in relation to quantitative PCR (qPCR), with an R2 value >0.98. The visualization of colorimetric changes in the different PCV-2 concentrations was possible without the use of equipment. The biosensor production methodology presented reproducibility and specificity, as well as easy synthesis and low cost. An enhanced version of it may be used in the future to replace traditional tests such as PCR.
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: The aim of the current study is to present a strategy to improve the efficiency of 5-fluorouracil (5-FU), which is widely used as antineoplastic agent against solid tumors-based on the use of gold nanocarriers to overcome the resistance of colorectal cancer cells. 5-FU was loaded on gold nanoparticles (AuNP) coated with anti-EGFR antibodies in order to target them towards colorectal cancer cells that overexpress epidermal growth factor receptors (EGFR). Physicochemical characterization has shown that AuNP size was approximately 20 nm and that AuNP functionalization led to spherical nanoparticles. Flow cytometry allowed observing that some compounds synthesized by our research group have induced apoptosis/necrosis and impaired the proliferation of colon cancer cell lines 'HCT-116' and 'HT-29'. The antibody/drug combination in AuNP (AuNP 5FU EGFR) has improved the apoptosis rate and impaired cell proliferation in both cell lines, regardless of the exposure time. Overall, these results have shown that AuNP functionalization with monoclonal antibodies focused on delivering 5-FU to tumor cells is an exciting strategy against colorectal cancer.
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A new immunosensor using hybrid nanomaterials for the detection of dengue virus was demonstrated in this work. This immunosensor composed of nanoparticles of γ-Fe2O3(SAMN) modified with MPA- SAMN@MPA was characterized by FTIR spectroscopy, transmission electron microscopy,quartz crystal microbalance, UV-vis and LSPR technique. The binding of SAMN@MPA with AuNPs conjugated with aptamers(SAMN@MPA@AuNPs@aptamer) provides specific chemical bonds to four dengue serotypes. Colorimetric changes in the modification steps provided rapid visual detection of the virus without the use of equipment. Variations of aptamers concentrations 1.0-10.0 µM where the 3.0 µM aptamer concentration is sufficient to completely cover the surface of the modified AuNPs with an R2 value of>â¯0.99. This new proposed methodology presenting some advantages in relation to traditional detection methods such as time optimization and cost,can be used as a diagnostic method.
Assuntos
Aptâmeros de Nucleotídeos/química , Vírus da Dengue/isolamento & purificação , Óxido Ferroso-Férrico/química , Imunoensaio , Nanopartículas de Magnetita/química , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
The aim of the present research is to propose a new method based on localized surface plasmon resonance (LSPR) for fast dengue virus detection. A pool with four dengue serotypes (DENV-1, -2, -3, -4) was detected through antigen-antibody binding using gold nanoparticles (AuNPs) as signaling antibody carriers. Such result was confirmed through surface plasmon resonance (SPR), transmission electron microcopy (TEM), and dynamic light scattering (DLS) techniques. The limit of detection was calculated for TCID50 107 demonstrating a linear correlation between viral concentration and number of cells with an r2 value of > 0.993. The assay presented good sensibility and reproducibility of results and the negative controls were not mistakenly detected. This design requires no pretreatment or high trained person. In the future, it can be used in commercial antibody detection kits.