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We report a simple and economical colorimetric bacterial sensing strategy with catalytic amplification using dopamine-capped iron oxide (Dop-Fe3O4) nanoparticles. These nanoparticles catalyse the oxidation of a chromogenic substrate in the presence of H2O2 into a green colored product. The catalytic activity of the nanoparticles is inhibited in the presence of bacteria, providing naked eye detection of bacteria at 104 cfu mL-1 and by spectrophotometric detection down to 102 cfu mL-1.
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Bacillus subtilis/aislamiento & purificación , Técnicas Biosensibles , Colorimetría , Dopamina/química , Escherichia coli/aislamiento & purificación , Nanopartículas de Magnetita/química , Catálisis , Tamaño de la Partícula , EspectrofotometríaRESUMEN
Protein-based biomaterials provide versatile scaffolds for generating functional surfaces for biomedical applications. However, tailoring the functional and biological properties of protein films remains a challenge. Here, we describe a high-throughput method to designing stable, functional biomaterials by combining inkjet deposition of protein inks with a nanoimprint lithography based methodology. The translation of the intrinsically charged proteins into functional materials properties was demonstrated through controlled cellular adhesion. This modular strategy offers a rapid method to produce customizable biomaterials.
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Nanoestructuras , Materiales Biocompatibles , Adhesión Celular , Humanos , Impresión , Proteínas , Propiedades de SuperficieRESUMEN
Effective detection of low molecular weight compounds in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is often hindered by matrix interferences in the low m/z region of the mass spectrum. Here, we show that monolayer-protected gold nanoparticles (AuNPs) can serve as alternate matrices for the very sensitive detection of low molecular weight compounds such as amino acids. Amino acids can be detected at low fmol levels with minimal interferences by properly choosing the AuNP deposition method, density, size, and monolayer surface chemistry. By inkjet-printing AuNPs at various densities, we find that AuNP clusters are essential for obtaining the greatest sensitivity. Graphical Abstract á .
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Aminoácidos/análisis , Oro/química , Nanopartículas del Metal/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Nanotecnología , Impresión , Propiedades de SuperficieRESUMEN
Prolonged retention of internalized nanoparticulate systems inside cells improves their efficacy in imaging, drug delivery, and theranostic applications. Especially, regulating exocytosis of the nanoparticles is a key factor in the fabrication of effective nanocarriers for chemotherapeutic treatments but orthogonal control of exocytosis in the cellular environment is a major challenge. Herein, we present the first example of regulating exocytosis of gold nanoparticles (AuNPs), a model drug carrier, by using a simple host-guest supramolecular system. AuNPs featuring quaternary amine head groups were internalized into the cells through endocytosis. Subsequent in situ treatment of a complementary cucurbit[7]uril (CB[7]) to the amine head groups resulted in the AuNP-CB[7] complexation inside cells, rendering particle assembly. This complexation induced larger particle assemblies that remained sequestered in the endosomes, inhibiting exocytosis of the particles without any observed cytotoxicity.
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Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Exocitosis , Nanopartículas del Metal/química , Aminas/química , Hidrocarburos Aromáticos con Puentes/química , Endosomas/metabolismo , Oro/química , Oro/metabolismo , Humanos , Imidazoles/química , Células MCF-7RESUMEN
Sensing clinically relevant biomolecules is crucial for the detection and prevention of disease. Currently used detection methods tend to be expensive, time intensive, and specific for only one particular biomolecule of interest. Nanoparticle-based arrays using conjugated polymers have emerged as an analytical and potential clinical tool, allowing detection of a wide range of biomolecules using selective, not specific, sensor components. In this report, we highlight recent progress in nanoparticle - polymer sensor arrays in both the fundamental understanding of how the sensor arrays function as well as the detection of clinically relevant bacteria and cells.
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Low-cost diagnostics for drinking water contamination have the potential to save millions of lives. We report a method that uses inkjet printing to copattern an enzyme-nanoparticle sensor and substrate on a paper-based test strip for rapid detection of bacteria. A colorimetric response is generated on the paper substrate that allows visual detection of contamination without the need for expensive instrumentation. These strips demonstrate a viable nanomanufacturing strategy for low-cost bacterial detection.
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Bacterias/aislamiento & purificación , Agua Potable/análisis , Nanopartículas/química , Colorimetría , Humanos , Impresión , Contaminación del AguaRESUMEN
The elastic modulus of an ultrathin nanoparticle (NP) monolayer film is tuned by modulating the binding strength between the NPs on a molecular level. NP monolayer films constructed by crosslinking NPs of different binding affinities are fabricated at oil/water interfaces. By inducing buckling patterns on these films, the correlation between the binding affinity of the NPs and the elastic modulus is investigated.
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Módulo de Elasticidad , Nanopartículas/química , Nanotecnología/métodos , Membranas Artificiales , Aceites/química , Propiedades de Superficie , Termodinámica , Agua/química , beta-Ciclodextrinas/químicaRESUMEN
Hydrogen bonding heavily influences conformations, rate of reactions, and chemical equilibria. The development of a method to monitor hydrogen bonding interactions independent of polarity is challenging as both are linked. We have developed two solvatochromic dyes that detect hydrogen-bond-donating solvents. The unique solvatochromism of the triazine architecture has allowed the development of probes that monitor hydrogen-bond-donating species including water.
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Drug delivery systems (DDSs) face several challenges including site-specific delivery, stability, and the programmed release of drugs. Engineered nanoparticle (NP) surfaces with responsive moieties can enhance the efficacy of DDSs for in vitro and in vivo systems. This triggering process can be achieved through both endogenous (biologically controlled release) and exogenous (external stimuli controlled release) activation. In this review, we will highlight recent examples of the use of triggered release strategies of engineered nanomaterials for in vitro and in vivo applications.
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Gold nanoparticles are engineered for direct imprinting of stable structures. This imprinting strategy provides access to new device architectures, as demonstrated through the fabrication of a prototype photoswitchable device.
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Catalytically active iron oxide nanoparticles are used as recognition elements and signal amplifiers for the array-based colorimetric sensing of proteins. Interactions between cationic monolayers on the Fe(3) O(4) NPs and analyte proteins differentially modulates the peroxidase-like activity of Fe(3) O(4) NPs, affording catalytically amplified colorimetric signal patterns that enable the detection and identification of proteins at 50 nM.
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Nanopartículas/química , Proteínas/análisis , Técnicas Biosensibles , Catálisis , Colorimetría/métodos , Compuestos Férricos/química , Peroxidasa/química , Peroxidasa/metabolismo , Proteínas/químicaRESUMEN
Patterns created by the inkjet printing of functionalized gold nanoparticles (NPs) can be selectively detected by laser desorption/ionization imaging mass spectrometry (LDI-IMS). These patterns can only be visualized by mass, providing a robust yet tunable system for potential anti-counterfeiting applications.
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Biocompatible structures are produced for cellular patterning. The biocompatible surfaces are generated to provide protein nonfouling patterns, offering direct communication to the cells for controlling cell adhesion and proliferation. These biofunctional surfaces provide a platform for aligning the cells in the direction of patterns, indicating potential application in the field of tissue engineering.
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Materiales Biocompatibles/química , Oro/química , Nanopartículas del Metal/química , Animales , Adhesión Celular/fisiología , Supervivencia Celular/fisiología , Nanopartículas del Metal/ultraestructura , Ratones , Células 3T3 NIH , Ingeniería de Tejidos/métodosRESUMEN
Gold nanoparticles (AuNPs) are important components for biomedical applications. AuNPs have been widely employed for diagnostics, and have seen increasing use in the area of therapeutics. In this mini-review, we present fabrication strategies for AuNPs and highlight a selection of recent applications of these materials in bionanotechnology.
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Biotecnología/métodos , Oro/uso terapéutico , Nanocápsulas/uso terapéutico , Nanomedicina/métodosRESUMEN
Nanoparticle-based arrays have been used to distinguish a wide range of biomolecular targets through pattern recognition. In this report, we highlight new 'chemical nose' methodologies that use nanoparticle systems to provide high sensitivity sensing of biomolecular targets, including fluorescent polymer/gold nanoparticle complexes that can discriminate between different bioanalytes including proteins, bacteria, and mammalian cells as well as dye-based micellar systems for the detection of clinically important metalloproteins and nonmetalloproteins.
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Técnicas Biosensibles/métodos , Membrana Celular/química , Nanopartículas del Metal/análisis , Animales , Humanos , Nanopartículas del Metal/química , Metaloproteínas/químicaRESUMEN
Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective immobilization of amine-functionalized silica nanoparticles on gold substrates. The available amine groups on the upper surface of the immobilized silica nanoparticles were further utilized for postdeposition of additional materials including particles, dyes, and biomolecules. The robustness of dithiocarbamate-mediated immobilization enables orthogonal assembly on surfaces via selective removal of the masking thiol ligands using iodine vapor etching followed by further functionalization.