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Express and portable label-free DNA detection and recognition with SERS platform based on functional Au grating
摘要： Label-free SERS-based detection of DNA is considered as one of the most prospective analytical methods for portable and express bioanalysis. In this work, the SERS platform based on the functional surface plasmon polariton supported ordered structure is proposed as an extremely convenient and effective tool for the detection of specific DNA sequences. The designed SERS structure makes possible DNA analyses in near-real time using the portable Raman spectrometer, with high reproducibility and accuracy of the results and the detection limits of the order of 10-14 M. In order to overcome challenges, connected to meticulous affiliation and evaluation of Raman signals, principal component analysis (PCA) of raw SERS data was used for data evaluation. SERS results reproducibility was achieved through the creation of a periodical structure with homogenous distribution of plasmon energy, when the analysis functionality was implemented through the grafting of the oligonucleotide to gold surface and its further interaction with complementary, mispaired and noncomplementary oligonucleotides. It was demonstrated experimentally that with the SERS platform it is possible not only to detect and recognize pure DNA but also the simultaneous presence of complementary and mispaired DNA with estimation of their relative concentrations. Moreover, the developed SERS sensor demonstrated the perfect stability over 3 months storage period without loss of functionality.
关键词： surface functionalization,DNA recognition,label-free,plasmonic substrate,SERS
更新于2025-09-09 09:28:46
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Simultaneous reduction and surface functionalization of graphene oxide for highly conductive and water dispersible graphene derivatives
摘要： A simple and effective preparation method for the simultaneous reduction and functionalization of graphene oxide (rGO) by 2,4-diamino benzene sulfonic acid has been developed. The derivatives exhibit excellent conductivity and high dispersibility in various solvents. The successful preparation of rGO and the presence of the sulfonated aromatic diamine on rGO surface has been confirmed by infrared and X-ray photoelectron spectroscopy, while, the analysis by micro-Raman spectroscopy indicated that the reduction/functionalization alters the lattice structure of GO by the increment the defect density when the 2,4-diamino benzene sulfonic acid is used. Moreover, the study of the dried products by X-ray diffraction spectroscopy suggested the turbostratic restacking of the exfoliated rGO into graphite-like nanostructures. The obtained derivative of simultaneous reduction and functionalization of GO was used for the preparation of highly conductive water-based gravure ink, which in turn, was successfully applied in printing on various flexible substrates, demonstrating its great potentiality in graphene-based flexible and printed electronics applications.
关键词： Conductive inks,Printed electronics,Surface functionalization,Gravure,Reduced graphene oxide
更新于2025-09-09 09:28:46
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Functionalization of Nanodiamond with Four Kinds of Epoxies
摘要： In this work, a simple and effective method for the covalent functionalization of nanodiamond (ND) with four epoxies has been developed. After homogenization by mixed acids and thionyl chlorides, the surface of ND was modi?ed with triethylenetetramine (TETA) to possess amine groups, which were used as active points to react with epoxy by ring opening reaction. Four different epoxies used are bifunctional diglycidyl ether of bisphenol-A (DGEBA), trifunctional triglycidyl p-amino phenol (TGAP), tetrafunctional tetraglycidyldiamino diphenylmethane (TGDDM) and bisphenol-A novolac epoxy resin (BAEPN). FT-IR spectra revealed that the epoxy was covalently attached to the ND (ND-g-epoxy). In addition, functionalized ND particles were characterized with WAXD and UV-Vis spectra to con?rm the result. The weight gains as a result of the epoxy-functionalized ND were determined by TGA analysis. The ND-g-epoxy particles were better dispersed in common organic solvents and the average diameters were characterized. The better dispersion and of the modi?ed ND were identi?ed from the SEM images.
关键词： Epoxy,Functionalization,Nanodiamond,Dispersion
更新于2025-09-09 09:28:46
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A Review on BiOX (X= Cl, Br and I) Nano-/Microstructures for Their Photocatalytic Applications
摘要： In the recent past, bismuth oxyhalides (BiOX) have been widely used for the photocatalytic degradation of the organic pollutants and other environmental remediation because of their higher stability, economic viability, nontoxicity and effective charge separation. We begin with the review of the different approaches adopted so far for BiOX (X = Cl, Br, and I) synthesis and a study of their photocatalytic performances under UV and visible light towards the various organic as well as inorganic pollutants. Later on, a study on further enhancement of the ef?ciency of BiOX under UV and visible light irradiation using recent advancements would be presented. The new approaches involve controlled morphology by forming composite and hybrid materials with other semiconductors and also doping with other metals and nonmetals that would undoubtedly be bene?cial in the interfacial charge transfer and ef?cient inhibition of the photo-generated species. Herein, we would also exploit the recent developments in the research strategies for enhancing photocatalytic activity of BiOX.
关键词： Pollutants,Photocatalysts,Functionalization,Stability,Bismuth Oxyhalides,Heterostructures,Photogenerated Species,Environmental Remediation,Composites,Photodegradation,Visible Light
更新于2025-09-09 09:28:46
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Lanthanide-doped Hafnia Nanoparticles for Multimodal Theranostics: Tailoring the Physicochemical Properties and Interactions with Biological Entities
摘要： High-Z metal oxide nanoparticles hold promise as imaging probes and radio-enhancers. Hafnium dioxide nanoparticles have recently entered clinical evaluation. Despite promising early clinical findings, the potential of HfO2 as a matrix for multimodal theranostics is yet to be developed. Here, we investigate the physicochemical properties and the potential of HfO2-based nanoparticles for multimodal theranostic imaging. Undoped and lanthanide (Eu3+, Tb3+, and Gd3+)-doped HfO2 nanoparticles were synthesized and functionalized with various moieties, including poly(vinylpyrrolidone) (PVP), (3-aminopropyl)triethoxysilane (APTES) and folic acid (FA). We show that different synthesis routes, including direct precipitation, microwave-assisted synthesis, and sol-gel chemistry allow preparation of hafnium dioxide particles with distinct physicochemical properties. Sol-gel based synthesis allows preparation of uniform nanoparticles with dopant incorporation efficiencies superior to the other two methods. Both luminescence and contrast properties can be tweaked by lanthanide doping. We show that MRI contrast can be unified with radio-enhancement by incorporating lanthanide dopants in the HfO2 matrix. Importantly, ion leaching from the HfO2 host matrix in lysosomal-like conditions was minimal. For Gd:HfO2 nanoparticles, leaching was reduced >10× compared to Gd2O3 and no relevant cytotoxic effects have been observed in monocyte-derived macrophages for nanoparticle concentrations up to 250 μg/mL. Chemical surface modification allows further tailoring of the cyto- and hemocompatibility and enables functionalization with molecular targeting entities, which lead to enhanced cellular uptake. Taken together, the present study illustrates the manifold properties of HfO2-based nanomaterials with prospective clinical utility beyond radio-enhancement.
关键词： x-ray,magnetic resonance imaging,functionalization,bioimaging,hafnium dioxide
更新于2025-09-09 09:28:46
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Reduced Graphene Oxide–TiO2 Nanotube Composite: Comprehensive Study for Gas Sensing Applications
摘要： Graphene oxide (GO) and reduced graphene oxide (RGO) have unique properties that can revolutionize performances of functional devices. Graphene-based materials can be coupled with metal oxide nanomaterials for gas sensing applications. In this work, we report the synthesis and the gas sensing properties of a composite material based on RGO loaded TiO2 nanotubes. To properly tune the reduction of GO to RGO we adopted a gas-phase process that can be applied in situ on each gas sensor device, allowing to track the process effects through the sensor conductance. We systematically investigated the gas-response dependence from RGO loading and its reduction, showing the occurrence of an optimal RGO concentration arising from the interplay of these two parameters. Hence, these two factors should be considered in parallel to functionalize the metal oxide materials with GO for the fabrication of chemical sensor devices.
关键词： TiO2 nanotube,gas sensing,reduced graphene oxide,reduction effect,surface functionalization,Graphene oxide
更新于2025-09-09 09:28:46
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Tailoring the Linear and Second-Order Nonlinear Optical Responses of the Titanium-MIL-125 Metal-Organic Framework through Ligand Functionalization: A First Principles Study
摘要： Density functional theory calculations have been performed to investigate the linear and second order nonlinear optical (NLO) properties of titanium-based MIL-125 metal-organic frameworks in crystalline form, in which the 1,4-benzene-dicarboxylate (BDC) linkers are modified by introducing different functional groups or by extending BDC ligand to contain two (MIL-126) and three (MIL-127) benzene rings. Our results reveal that the functionalization of BDC linker tends to increase the dielectric constants and the magnitude of birefringence of MIL-125, especially for the aminated derivatives. Correspondingly, the incorporation of substituent group will improve the phase matching performance of MIL-125. As for the second harmonic generation (SHG) susceptibility, the SHG activity of the pristine MIL-125 is comparable to KDP, which can be attributed mostly to the contributions of TiO5(OH) octahedra. It is noted that after introducing substituent group into BDC linker, the organic part will have a remarkable influence on the SHG intensity. However, the specific effect on the NLO response is dependent on the type of functional group incorporated into BDC ligand, and only the inclusion of amine group that is strongly electron-donating can obviously enhance the SHG activity of MIL-125. In addition, MIL-126 and MIL-127 with longer aromatic linking unit are not suitable to act as NLO materials due to their poor phase matching abilities, but they are the promising candidates for the low dielectric constant materials. The present study can provide theoretical insights to design new second-order NLO materials based on MIL-125.
关键词： Nonlinear Optical Properties,Density Functional Theory,Hybrid Materials,Ligand Functionalization,Metal-Organic Framework,Plasmonics,Optical,Magnetic
更新于2025-09-04 15:30:14
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Azide Passivation of Black Phosphorus Nanosheets: Covalent Functionalization Affords Ambient Stability Enhancement
摘要： Two-dimensional (2D) black phosphorus (BP) has been attracting ever-growing interest due to its unique band structure, but suffers from low ambient stability owing to its high reactivity to oxygen. Covalent functionalization has been demonstrated to passivate the reactive BP effectively, however the reported covalent functionalization methods are quite limited to aryl diazonium and nucleophilic additions affording P-C and P-O-C single bonds, for which the retaining of one unpaired electron in the Group-VA phosphorus atom hampers the passivation effect. Herein, we report for the first time covalent azide functionalization of BP nanosheets (BPNSs), leading to significant enhancement of the ambient stability of BP as confirmed by UV-vis spectroscopic studies. The most stable configuration of the azide functionalized BPNSs is predicted by theoretical calculations, featuring the grafting of benzoic acid moiety onto BPNSs (f-BPNSs) via the unprecedented P=N double bonds formed through in-situ nitrene as a reactive intermediate.
关键词： covalent functionalization,2D nanosheets,nitrene,black phosphorus,azide
更新于2025-09-04 15:30:14
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A sol-gel polymerization method for creating nanoporous polyimide silsesquioxane nanostructures as soft dielectric materials
摘要： A sol–gel polymerization method was developed to make polyimide (PI) silsesquioxane (SSQ) nanoparticles as functional, soft dielectric materials. The surface functionalization of the polymer chain backbone and chain ends of poly(trimellitic anhydride chloride-co-4,40-methylenedianiline), PMR-15 resin, with para-(chloromethyl)-phenylethyltrimethoxy silane yielded a novel sol–gel reactive sites functionalized PMR-silane precursor. Upon base-catalyzed hydrolysis and condensation of the PMR-silane precursor, spherical, raspberry-like PMR-SSQ nanoparticles were obtained in considerably good yield. Controlling the particle size distribution was attempted upon adjusting the molar ratio between the silane precursor and the base, as well as in the presence of a catalytic amount of silica sols. Particle composition, thermal stability, and morphology were confirmed from Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy analyses. Nanoparticles, visualized under transmission electron microscopy exhibit a nanoporous structure. The Brunauer–Emmett–Teller analysis confirmed that the average pore dimension is ranged from 2 to 5 nm. The dielectric constant of PMR-SSQ nanoparticles was as low as 1.95, compared to dielectric constants of 3.05 and 3.13 for PMR-15 and PMR-silane, respectively. Thus, the base-catalyzed sol–gel polymerization of alkoxysilylated PI offers a novel synthetic path to make functional nanoporous PI nanostructures that possess ultralow dielectric constants.
关键词： resin,polyimides,polymer functionalization,soft dielectric materials,thermoplastics
更新于2025-09-04 15:30:14
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Electronic properties of B12N12 fullerene–like nanoclusters functionalized with Schiff bases: a DFT study
摘要： In the present study, electronic properties of B12N12 nanocage functionalized with Schiff bases are studied by means of density functional theory (DFT) calculations at wB97XD/6-31+G(d,p) computational level. Adsorption of Schiff bases on the surface of B12N12 nanocage leads to one local minimum with the adsorption energy in the range of ? 63.61 and ? 157.37 kJ/mol. Effect of substitution of Schiff bases with electron-donating and electron-withdrawing groups on the adsorption energy, electronic properties, and thermodynamic parameters of studied complexes has been reported. In general, adsorption of H2C=N–C6H4–R Schiff bases on B12N12 nanocage is stronger than adsorption of R2C=N–C6H5 moieties. The result of present study may be used for surface modification of B12N12 nanocage based on interaction with Schiff bases.
关键词： DFT,B12N12 nanocage,TDOS,Schiff base,Functionalization
更新于2025-09-04 15:30:14