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Nanotechnology has become more and more potentially used in diagnosis or treatment of diseases. Advances in nanotechnology have led to new and improved nanomaterials in biomedical applications. Common nanomaterials applicable in b...
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Nanotechnology has become more and more potentially used in diagnosis or treatment of diseases. Advances in nanotechnology have led to new and improved nanomaterials in biomedical applications. Common nanomaterials applicable in biomedical applications include liposomes, polymeric micelles, graphene, carbon nanotubes, quantum dots, ferroferric oxide nanoparticles, gold nanoparticles (Au NPs), and so on. Among them, Au NPs have been considered as the most interesting nanomaterial because of its unique optical, electronic, sensing and biochemical properties. Au NPs have been potentially applied for medical imaging, drug delivery, and tumor therapy in the early detection, diagnosis, and treatment of diseases. This review focuses on some recent advances in the use of Au NPs as drug carriers for the intracellular delivery of therapeutics and as molecular nanoprobes for the detection and monitoring of target molecules. View Full-Text
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A novel dual-signal ratiometric electrochemical nanosensor for highly sensitive and selective detection of Ag+ ion has been designed on the basis of decreasing overpotential of high nitrogen doped carbon nanosheets and poly(dially...
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A novel dual-signal ratiometric electrochemical nanosensor for highly sensitive and selective detection of Ag+ ion has been designed on the basis of decreasing overpotential of high nitrogen doped carbon nanosheets and poly(diallyldimethylammonium chloride)-coated oxidized single-walled carbon nanotubes (HNCNs/PDDA/SWCNTs) and highly specific response strategy. The formation of HNCNs/PDDA/SWCNTs nanocomposite not only provides a higher surface area, but also nitrogen- hole microenvironment for retaining the native activity of the reacted Ag+ ion. As a ratiometric amperometric sensor, the resulting HNCNs/PDDA/SWCNTs nanocomposite-modified electrode exhibited high sensitivity and selectivity for the detection of Ag+ ion in the range of 5 nM-10 μM and 10-200 μM with a detection limit of 1.97 nM (S/N = 3). The results indicated that the synergetic effect with PDDA/SWCNTs changes the analytical path of the HNCNs matrix for Ag+ ion detection. This work demonstrated that HNCNs/PDDA/SWCNTs nanocomposite possesses the feasibility and potential applications in electrochemical sensing.
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Graphene quantum-dot-like structures of highly enriched N-based dual-color single-functional polymer carbon nanosheets (GLNPCNs) with an average diameter as large as 170 nm (ca. five layers) are prepared through a facile hydrother...
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Graphene quantum-dot-like structures of highly enriched N-based dual-color single-functional polymer carbon nanosheets (GLNPCNs) with an average diameter as large as 170 nm (ca. five layers) are prepared through a facile hydrothermal method. Intermolecular C_5H_5N_5···C_5H_5N_5 and/or C_2H_5OH chemical polymerization interactions in the liquid state of the peripheral crown-ether-like "hole"-decorated compound GLNPCNs lead to a fascinating 2D supramolecular polymer architecture, which exhibits near-ultraviolet (NUV) fluorescence, ultrahigh brightness, a narrow fullwidth at half-maximum, and excellent potential for practical applications. The unique NUV fluorescence of the GLNPCNs might be attributed to the "self-passivated" crown-ether-like layer on their surface; the GLNPCNs exhibit properties independent of the excitation wavelength, which is unexpected in the NUV region. Moreover, these GLNPCNs show highly selective and sensitive detection of hazardous and toxic silver (Ag~+) ions, and discriminate other metal ions or anions in the range 1.5 nm to 50 μm through a fluorescence quenching response. The high sensing selectivity toward Ag~+ ions could be attributable to the restricted rigid conformation of the peripheral crown-ether-like "hole", which binds exclusively to the Ag~+ ion. In addition to Ag~+ ion sensing, the GLNPCNs quenched by Ag~+ ions exhibit high selectivity and sensitivity for cysteine (Cys) in the range 2.0 nm to 50 μm through a fluorescence recovery process, which could be attributed to the effective coordination/chelation interactions between Ag~+ ions and the plentiful mercapto and amino groups of Cys. Our results suggest that the facile preparation, biocompatibility, outstanding photoluminescence, and physicochemical properties of these GLNPCNs make them potentially useful in numerous applications such as bioimaging, optical and electrochemical sensors, and energy devices.
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p-Nitrophenol and its derivatives can cause serious harm to the health of mankind and the earth's ecosystem. Therefore, it is necessary to develop a novel and rapid detection technology for p-nitrophenol and its derivative. Herein...
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p-Nitrophenol and its derivatives can cause serious harm to the health of mankind and the earth's ecosystem. Therefore, it is necessary to develop a novel and rapid detection technology for p-nitrophenol and its derivative. Herein, excellent water-soluble, large-size and dual-emissive neuron cell-analogous carbon-based probes (NCNPs) have been prepared via a solvothermal approach, using o-phenylenediamine as the only precursor, which exhibit two distinctive fluorescence (FL) peaks at 420 and 555 nm under 345 nm excitation. The NCNPs show a neuron cell-like branched structure, are cross-connected, and are in the range of 10-20 nm in skeleton diameter. Interestingly, their blue-green dual-colour fluorescence is quenched by p-nitrophenol or its derivative due to the specific mechanism of the π?π stacking interactions or internal filtration effect. Accordingly, a simple, rapid, direct and free-label ratiometric FL detection of p-nitrophenol is proposed. An excellent linear relationship shows linear regions over the range of 0.1-50 μM between the ratio of the FL intensity (FL555 nm/FL420 nm) and the concentrations of p-nitrophenol. The detection limit is as low as 43 nM (3σ). Importantly, the NCNP-based probe also shows acceptable repeatability and reproducibility for the detection of p-nitrophenol and its derivatives, and the recovery results for p-nitrophenol in real wastewater samples are favourable.
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Herein, a novel and convenient electrochemical sensor based on a glassy carbon electrode modifiedwith multi-walled carbon nanotubes-titanium nitride (MWCNTs-TiN) film for sensitive and efficientdetection of bisphenol A (BPA) was d...
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Herein, a novel and convenient electrochemical sensor based on a glassy carbon electrode modifiedwith multi-walled carbon nanotubes-titanium nitride (MWCNTs-TiN) film for sensitive and efficientdetection of bisphenol A (BPA) was developed. Several important parameters controlling theperformance of the sensor, such as scan rate, the volume of MWCNTs-TiN dispersion and the pHvalue of buffer solution, were be investigated and optimized by cyclic voltammetry (CV) anddifferential pulse voltammetry (DPV). It was notable that the oxidation peak current of BPA hadenhanced greatly and the oxidation overpotential had decreased significantly. Under the optimizedconditions, the oxidation peak current was proportional to BPA concentration in the range of 0.1- 50M, and the detection limit was 0.05M. Meanwhile, the modified electrode was also exhibitedgood reproducibility and stability, and was employed to in-situ determinate BPA in water samples withsatisfying results.
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Currently, as food additives, synthetic colourants have been drawn much attention. This paper studiedthe electrocatalytic oxidation of amaranth (AM), with a novel electrochemical sensor based on single- walled carbon nanotube-Tita...
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Currently, as food additives, synthetic colourants have been drawn much attention. This paper studiedthe electrocatalytic oxidation of amaranth (AM), with a novel electrochemical sensor based on single- walled carbon nanotube-Titanium nitride (SWCNT-TiN) nanocomposites modified glassy carbonelectrode. Owing to the high accumulation effect and great catalytic capability of SWCNT-TiNnanocomposites, the developed sensor exhibited well-defined voltammetric peaks for AM. The peakcurrents of AM increased linearly with its concentration in the ranges of 0.1-100 M. The detectionlimit is 40 nM. The developed sensor was successfully applied in the determination of AM in beveragesamples. Results indicated that the developed sensor was fast, sensitive and reliable.
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Recently, the development of a novel fluorescent (FL) nanoprobe for ratiometric detection of antibiotics in real-world samples has received more and more attention. In this article, the distinctive optical properties of deep-ultra...
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Recently, the development of a novel fluorescent (FL) nanoprobe for ratiometric detection of antibiotics in real-world samples has received more and more attention. In this article, the distinctive optical properties of deep-ultraviolet emission, a narrowed full width at half maximum (~20 nm) and excitation-independent emission of a carbonized nanoprobe (CNP) were easily prepared by an environmentally friendly approach of solvothermal treatment using melamine as the precursor and H_2O as the solvent. The obtained CNP can be further utilized as an efficient ratiometric FL nanoprobe for enrofloxacin (EFC) and feroxacin (FXC) detection based on the fact that the FL quenching of the CNP was accompanied by an FL increase with EFC/FXC based on the inner filter effect (IFE). Under the optimal conditions, excellent linear relationships existed between the relative FL intensity (FL_(290 nm)/FL_(412 nm), CNP for FL_(290 nm) and antibiotics for FL_(412 nm)) and the concentrations of FXC and EFC in the range of 0.05-500.0 μM and 0.05-200.0 μM, with limits of detection of 21.74 and 22.43 nM (3σ/k), respectively. With the proposed ratiometric FL sensor, FXC and EFC in milk and serum samples can be rapidly and selectively analyzed without tedious pretreatment processes for real-world samples.
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In this study, a novel nanocomposite material consisted of oxygen-doped, nitrogen-rich carbon nanoribbons polymer and single-walled carbon nanotubes (ONPCNRs/SWCNTs) has been facilely synthesized through simply electrostatic inter...
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In this study, a novel nanocomposite material consisted of oxygen-doped, nitrogen-rich carbon nanoribbons polymer and single-walled carbon nanotubes (ONPCNRs/SWCNTs) has been facilely synthesized through simply electrostatic interaction process using poly(diallyldimethylammonium chloride) polycationic compound (PDDA). During the synthesis, the N-containing of ONPCNRs could undergo protonation to produce protonated compound under pH 6.5 condition, which could improve electrocatalytic activity of the vertically aligned N-containing ONPCNRs/SWCNTs nanocomposite due to the electron withdrawing ability of nitrogen atoms to create net positive charge on the adjacent carbon atoms in the PDDA-modified SWCNTs (PDDA/SWCNTs) plane. Meanwhile, due to the high N-doping ONPCNRs have high adsorption capacity and selectivity toward H_2O_2 adsorption, the combination of PDDA/SWCNTs and use of high N-doping ONPCNRs overlayer lead to an effective reduction in overpotential, enhanced Faradaic efficiencies and current densities for H_2O_2 reduction to H_2O. As a non-enzymatic amperometric sensor, the resulting ONPCNR/SWCNTs nanocomposite-modified electrode exhibited high sensitivity and selectivity for the detection of H_2O_2 in the range of 1.0-500 μM with a detection limit of 0.51 μM (S/N=3). The results indicated that the synergetic effect with ONPCNRs improves the capability of the PDDA/SWCNTs matrix for H_2O_2 detection. This work demonstrated that ONPCNRs/SWCNTs nanocomposite possesses the feasibility and potential applications in sensing.
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A simple one-pot reduction/decoration strategy was reported to produce Au nanoparticles (NPs) dotted three-dimensional (3D) porous reduced graphene oxide-single walled carbon nanotube (rGO-SWCNT-Au) nanocomposites. In the synthesi...
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A simple one-pot reduction/decoration strategy was reported to produce Au nanoparticles (NPs) dotted three-dimensional (3D) porous reduced graphene oxide-single walled carbon nanotube (rGO-SWCNT-Au) nanocomposites. In the synthesis process, GO was used to disperse SWCNT and the obtained GO-SWCNT conjugate was used as supporting material to further disperse in situ growing Au NPs. Bovine serum albumin (BSA) was used as both reducing and stabilizing agent to reduce GO and HAuCl_4 and to stabilize rGO-SWCNT and Au NPs. The morphology and microstructure characterization revealed that the proposed method could lead to the simultaneous reduction of GO and HAuCl_4 together with efficient dispersion of Au NPs on the surface of rGO-SWCNT. Furthermore, electrochemical experiments demonstrated that rGO-SWCNT-Au nanocomposites could be used as electrocatalysts towards the oxidation of glucose, leading to an enzymeless glucose sensor with a wide linear range and a lower detection limit.
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Chemical modification with foreign atoms is a leading strategy to intrinsically modify the properties of host materials. Among them, potassium (K) modification plays a critical role in adjusting the electronic properties of carbon...
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Chemical modification with foreign atoms is a leading strategy to intrinsically modify the properties of host materials. Among them, potassium (K) modification plays a critical role in adjusting the electronic properties of carbon materials. Craphene, a true 2D carbon material, has shown fascinating applications in electrochemical sensing and biosensing. In this work, a facile and mild strategy to K-modifying in graphene at room-temperature is reported for the first time. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), transmission electron microscopy (TEM), Raman spectra, and cyclic voltammetry are used to characterize this K-modified graphene. The K-modified graphene is capable of acting as an electron transfer medium and more efficiently promotes charge transfer than unmodified graphene. A highly sensitive and stable amperometric sensor based on its excellent electrocata-lytic activity toward the oxidation of NO_2~- is proposed. The sensor shows a linear range from 0.5 μm to 7.8 mm with a detection limit of 0.2 μm at a signal-to-noise ratio of 3. The modified electrode has excellent analytical performance and can be successfully applied in the determination of NO_2~- released from liver cancer and leukemia cells and shows good application potential in biological systems.
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