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Peptide-Functionalized Quantum Dots for Rapid Label-Free Sensing of 2,4,6-Trinitrotoluene
摘要： Explosive compounds, such as 2,4,6-trinitrotoluene (TNT), pose a great concern in terms of both global public security and environmental protection. There are estimated to be hundreds of TNT contaminated sites all over the world, which will affect the health of humans, wildlife, and the ecosystem. Clearly, the ability to detect TNT in soils, water supplies, and wastewater is important for environmental studies but also important for security, such as in ports and boarders. However, conventional spectroscopic detection is not practical for on-site sensing because it requires sophisticated equipment and trained personnel. We report a rapid and simple chemical sensor for TNT by using TNT binding peptides which are conjugated to fluorescent CdTe/CdS quantum dots (QDs). QDs were synthesized in the aqueous phase, and the peptide was attached directly to the surface of the QDs by using thiol groups. The fluorescent emission from the QDs was quenched in response to the addition of TNT. The response could even be observed by the naked eye. The limit of detection from fluorescence spectroscopic measurement was estimated to be approximately 375 nM. In addition to the rapid response (within a few seconds), selective detection was demonstrated. We believe this label-free chemical sensor contributes to progress for the on-site explosive sensing.
关键词： quantum dots (QDs),explosive detection,2,4,6-trinitrotoluene (TNT),label-free sensing,peptide-functionalized
更新于2025-11-14 15:23:50
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Preparation of DNA functional phosphorescent quantum dots and application in melamine detection in milk
摘要： Bio-functionalization of quantum dots (QDs) is of important value in practical applications. With single-stranded DNA (ssDNA) rich in thymine T and thioguanine G taken as the template, a new-type nanocomposite material (ssDNA-PQDs) synthesized from low-toxicity T-ssDNA functionalized Mn–ZnS and room-temperature phosphorescent (RTP) QDs (PQDs) was prepared in this paper by optimizing synthesis conditions, and these ssDNA-PQDs could emit orange RTP signals at 590 nm. As these ssDNA-PQDs are rich in T sequences and T sequences can bond with melamine through the hydrogen-bond interaction, ssDNA-PQDs experience aggregation, thus causing phosphorescent exciton energy transfer (PEET) between ssDNA-PQDs of di?erent particle sizes and their RTP quenching. Based on this principle, an RTP detection method for melamine was established. The linear range and detection limit of the detection method are 0.005–6 mM and 0.0016 mM respectively. As this method is based on the RTP nature of ssDNA-PQDs, it can avoid disturbance from background ?uorescence and scattered light of the biological ?uid, and it is very suitable for melamine detection in the biological ?uid milk.
关键词： DNA functionalized quantum dots,milk safety,melamine detection,room-temperature phosphorescent
更新于2025-11-14 15:23:50
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Functionalized Single-Atom-Embedded Bilayer Graphene and Hexagonal Boron Nitride
摘要： Single-atom-embedded bilayer graphene and two-dimensional hexagonal boron nitride are proposed in terms of first-principles calculations. In particular, a series of 68 different single atoms are embedded within bilayer graphene and boron nitride. It is revealed that the magnetic moment and bandgap behave differently depending on the atomic element used for doping where it becomes possible to form a magnet, conductor, semiconductor, or insulator. The electronic and geometrical properties of bilayer graphene and boron nitride are, in principle, able to be tailored and tuned, thereby expanding on how two-dimensional materials are functionalized and designed.
关键词： single atom,boron nitride,bandgap,graphene,functionalized graphene,magnetic moment
更新于2025-09-23 15:23:52
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Amino-Functionalized Al-MOF for Fluorescent Detection of Tetracyclines in Milk
摘要： A fluorescent method for detection of tetracyclines (TCs) in milk was developed by using the NH2-MIL-53(Al) nanosensor synthesized via a one-pot hydrothermal method. The nanosensor had a crystalline nanoplates structure with rich groups of -NH2 and -COOH. The -NH2/-COOH of NH2-MIL-53(Al) reacted with the -CO-/-OH of TCs to form a complex. The electron of -NH2/-COOH from the NH2-BDC ligand transferred to the -CO-/-OH of TCs. -NH2 of the NH2-MIL-53(Al) interacted with the -CO-/-OH of TCs by hydrogen bonding. Quenching efficiency of inner filter effect (IFE) was calculated to contribute 57-89%. The synergistic effect of photoinduced electron transfer (PET) and IFE account for fluorescence quenching. TCs were quantitatively detected in milk samples with recoveries of 85.15 ~ 112.13%, the results were in great accordance with high performance liquid chromatography (HPLC) (P > 0.05), confirming the NH2-MIL-53(Al) nanosensor has potential applicability for the detection of TCs in food matrix.
关键词： Nanosensor,inner filter effect (IFE),Amino-functionalized organic Metal Framework,Tetracyclines,Fluorescence detection,Milk
更新于2025-09-23 15:23:52
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(Bz) <sub/><i>n</i> </sub> and (VBz) <sub/><i>n</i> </sub> covalent functionalized MoS <sub/>2</sub> monolayer: electronic and transport properties
摘要： Inspired by Benzene (Bz) derivatives dramatically enhancing MoS2 monolayer electronic properties (ACS Nano. 2015, 9, 6018–6030), we have investigated electronic and transport properties of (Bz)n/MoS2 and (VBz)n/MoS2, which are designed by grafting (Bz)n and (VBz)n arrays onto 2D monolayer MoS2 (ML-MoS2), respectively, using density functional theory (DFT) and non-equilibrium Green’s function (NEGF) methods. ML-MoS2 provides a perfect substrate for grafting (Bz)n and (VBz)n arrays upon its surface as a result of stable covalent binding energy with -3.841 eV and -1.953 eV for (Bz)n/MoS2 and (VBz)n/MoS2 respectively. From the electronic properties, we can find that grafting (Bz)n onto the ML-MoS2 surface turns ML-MoS2 from typical semiconductor to metallic properties because four wide bands coupled by (Bz)n and MoS2 in (Bz)n/MoS2 show better delocalization in heterointerface, resulting to these bands across the Fermi level (Ef). Furthermore, the introduction of metal V. Transport properties of ML-MoS2, (Bz)n/MoS2 or (VBz)n/MoS2 for two-probe devices are all studied in zigzag and armchair direction. The ferromagnetic (VBz)n/MoS2 shows a spin polarized transport characteristic, spin-down state gives a higher conductivity than spin-up state. By comparison the zigzag direction is the preferential pathway for electron transport. Finally this work suggests that the novel (VBz)n nanowire grafted on MoS2 should have potential application in low-dimensional magnetic nanoelectronic devices.
关键词： (Bz)n/MoS2,(VBz)n/MoS2,covalent functionalized,electronic property,transport property
更新于2025-09-23 15:22:29
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Preparation of Functionalized SiO2 Microspheres by One Step Method
摘要： Functional silica microparticle is a kind of important inorganic non-metallic oxide with a wide range of applications in many fields due to its excellent chemical and thermal stabilities. Post modification is the most common functional method, but, low efficiency. In this paper, a new acid hydrolysis and subsequent alkaline condensation method was developed to prepare SiO2 microspheres with functional groups on surface by condensing or co-condensing functional organosilane precursors (γ-Aminopropyltriethoxysilane (APTES), γ-Mercaptopropyltriethoxysilane (MPTES) and γ-Mercaptopropyltrimethoxysilane (MPTMS) etc) with phenyltrimethoxysilane (PTMS). Series of characterization methods, such as IR, XPS and Raman, demonstrated that the surface of the as-prepared SiO2 microspheres was successfully functionalized with amine or sulfydryl groups. This method may provide a reference for one-step preparation of functional SiO2 microspheres.
关键词： Functionalized SiO2 microspheres,Condensation,One-step method
更新于2025-09-23 15:22:29
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Functionalized fluorescent carbon nanoparticles for sensitively targeted of folate-receptor-positive cancer cells
摘要： The folic acid-functionalized fluorescent carbon dots (FA-CDs) was synthesized via the assembly of FA to the surface of CDs. A facile hydrothermal method with proline and ethylenediamine as precursors was used to fabricate CDs. The as-prepared CDs possessed active amino groups where the CDs could be further engineered for the conjugation with FA. The uptake of the as-synthesized FA-CDs by FR positive MCF-7 cells (FR++) and HepG-2 cells (FR+) via receptor-mediated endocytosis was demonstrated by confocal laser scanning microscopy, which is further verified by a comparative study with FR-negative PC-12 cells (FR-). The bright fluorescence can be observed in FR positive MCF-7 cells while negligible fluorescence was observed in PC-12 cells with low-expressed FR, demonstrating that FA-CDs could accurately identify FR-positive cancer cells from normal cells. The FA-CDs shared favorable biocompatibility, excellent optical properties and ultra-low toxicity etc. Holding these superior properties, the FA-CDs was implemented as a highly effective platform for biological labeling and imaging, which may provide a innovative vision for cancer diagnosis and succeeding personalized therapy.
关键词： Folic acid-functionalized,Targeted bioimaging,Cancer cells,Carbon dots
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE SENSORS - New Delhi, India (2018.10.28-2018.10.31)] 2018 IEEE SENSORS - A Flexible Room Temperature Ammonia Sensor Based on Large Area, Transparent Single Wall Carbon Nanotube Thin Film
摘要： A low-temperature, wet-chemical process for the synthesis of single wall carbon nanotubes (SWCNTs) films on large area, transparent, flexible substrates were developed and its application to ammonia detection at room temperature were demonstrated. The carboxyl groups were attached in the sidewalls of carbon nanotubes due to wet-chemical process which helps to improve the sensor performance. The transmittance measurement showed that the film is ninety percent transparent to visible spectrum with respect to air. Selectivity measurements were also performed. The sensor responses were same for both the fat and bend film. The present SWCNTs based sensors could potentially be used to develop low cost, flexible, foldable and disposable sensor system for the monitoring of toxic gases like ammonia in environment.
关键词： functionalized SWCNTs,ammonia sensor,Flexible gas sensor,room temperature,gas sensor
更新于2025-09-23 15:22:29
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Enhanced photoacoustic and photothermal effect of functionalized polypyrrole nanoparticles for near-infrared theranostic treatment of tumor
摘要： Functionalized nanomaterials with near-infrared (NIR) responsive capacity are quite promising for theranostic treatment of tumors, but formation of NIR responsive nanomaterials with enhanced theranostic ability and excellent biocompatibility is still very challenging. Herein, PEGylated indocyanine green (ICG)-loaded polypyrrole nanoparticles (PPI NPs) were designed and successfully formed through selecting polydopamine as the linkage between each component, demonstrating enhanced NIR responsive theranostic ability against tumor. Combining in vitro cell study with in vivo assay, the formed PPI NPs were proved being fantastic biocompatible while effectively internalizing in HeLa cells and retaining in HeLa tumor demonstrated by in vitro flow cytometry/confocal measurement and in vivo photoacoustic imaging assay. With the guidance of photoacoustic imaging, successful photothermal ablation of tumor was achieved when treating with PPI NPs plus laser, which was much more effective than the group treated with NPs free of ICG. The greatly combined enhanced photoacoustic and photothermal effect is mainly ascribed to the functionalized polypyrrole nanoparticles, which could accumulate in tumor site more effectively with a relative longer retention time taking advantage of the nanomaterial-induced endothelial leakiness phenomenon. All these results demonstrate the designed PPI NPs possess enhanced NIR responsive property are to hold a great promise for tumor NIR theranostic applications.
关键词： polypyrrole nanoparticles,photoacoustic imaging,photothermal therapy,Functionalized nanomaterials,near-infrared (NIR) responsive,theranostic treatment
更新于2025-09-23 15:21:21
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Convergent and Functional-Group-Tolerant Synthesis of B-Organo BODIPYs
摘要： Boron-dipyrromethenes (BODIPYs) are one of the most important fluorescent materials. Despite their potential unique properties, however, B,B-fluoro-organo BODIPYs (BFR-BODIPYs) possessing an organo group (R) on the boron center have not been studied in detail, due in part to challenges related to their synthesis. In this paper, a convergent synthesis of BFR-BODIPYs operative under mild conditions is reported. Conversions of the thus-synthesized functionalized BFR-BODIPYs by cross-coupling, condensation, and SN2 reactions at the R group are also demonstrated.
关键词： convergent synthesis,Boron-dipyrromethenes,fluorescent materials,BODIPYs,functionalized BFR-BODIPYs
更新于2025-09-23 15:21:21