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•A high quality Cu/GO nanohybrid was fabricated via a facile one-step reduction method.•The Cu/GO nanohybrid displays excellent electrocatalytic property for the oxidation of ...2-NAP.•The Cu/GO electrode displays super comprehensive performances for the detection of 2-NAP.•This proposed method was successfully applied to detect 2-NAP in water samples.
A copper nanostructures-graphene oxide (Cu/GO) hybrid as a new electrocatalyst for highly sensitive detection of 2-naphthol (2-NAP) was successfully synthesized by a one-pot and in situ chemical reduction approach. The characterization results reveal that the cubic Cu nanostructures are tightly attached onto the GO sheets in the resulting hybrid. A lower oxidation potential and a larger peak current were observed for the 2-NAP oxidation at the Cu/GO modified electrode, demonstrating the synergistic electrocatalysis from Cu nanostructures and GO sheets. Consequently, the Cu/GO hybrid exhibits a low detection limit (5.0nM) and wide linear ranges (0.1–4.0μM and 4.0–130.0μM) when used as a sensing material for the sensitive detection of 2-NAP. Finally, the fabricated sensor was successfully applied in the detection of 2-NAP in real samples and satisfactory recoveries in the range of 99.3%–104.0% were achieved.
Hybrid composites containing Cu nanostructures (NSs), reduced graphene oxide (RGO), and polystyrene (PS) were produced for electromagnetic shielding application. First, Cu NSs including nanoparticles ...(NPs), nanorods (NRs), and nanowires (NWs) were prepared by a green method using eucalyptus bark extract from the reaction of copper(II) chloride in ethylene glycol (EG) at 186 °C. The FE-SEM images, XRD patterns, and Raman spectroscopy were used to characterize these NSs. The RGO/PS composite was prepared by introducing RGO to the PS matrix. The tensile test revealed that by adding 10% of RGO to the PS matrix, the tensile strength of the RGO/PS composite increased by 13.8%. The thermal properties of the RGO/PS composite indicated that with the uniform incorporation of RGO on the PS matrix, the thermal stability of the polymer composite was elevated to 350 °C and the Tg to 112 °C. Conductive polymer nanocomposites (PNCs) were prepared by adding Cu NSs to the RGO/PS composite. The results showed that these PNCs had electromagnetic interference (EMI) shielding; the shielding effectiveness of PNCs containing 10% RGO and 25% Cu NWs was 36.0 dB at 8.0 GHz and 29.5 dB at 12.0 GHz. The predominant mechanism of protection in the frequency range and percentages of the filler under study was of the reflection type.
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The Cu/RGO/PS polymer NCs have the ability of shielding against the interference of electromagnetic waves; so that the shielding effectiveness in the sample of polymer NCs containing 10 wt% of RGO and 25 wt% of Cu NWs were 36.0 dB at 8.0 GHz and 29.5 dB at 12.0 GHz.
•RGO & Cu NSs were prepared by a green method using eucalyptus bark extract.•Adding 10% RGO, the tensile strength of RGO/PS polymer composite increased by 13.8%.•Thermal stability and Tg of Cu/RGO/PS NCs increased to 350 and 112 °C, respectively.•Conductive polymer NCs was prepared by adding Cu NSs to RGO/PS polymer composite.•Shielding effectiveness of Cu/RGO/PS NCs were 36 dB at 8 GHz and 29.5 dB at 12.0 GHz.
For the efficient surface plasmon resonance (SPR)-based DNA assay researching, signal amplification tactics were absolutely necessary. In this work, a sensitive SPR-DNA sensor was developed by ...employing in situ synthesis of copper nanoparticles (CuNPs) templated by poly-T sequences DNA from terminal deoxynucleotidyl transferase (TdT)-mediated extension, and synergistically with nano-effect deposition as the mass relay. The objective of this strategy was manifold: firstly, tDNA hybridized with the optimal designed probes to active the TdT-mediated DNA extension onto the surface of SPR chip, resulted a long poly-T sequences ssDNA chain in dsDNA terminal onto surface of gold chip and characterized by SPR signal amplitudes. Secondly, copper ion (Cu2+) adsorbed into the skeleton of poly-T sequences DNA, with the aid of ascorbic acid (VC) to achieve the Cu2+ reduction, copper nanostructures (CuNPs) was synchronously generated onto the single nucleotide chain anchoring in dsDNA derivatives and the formation was featured by transmission electron micrographs (TEM) and electrochemistry. Lastly, dsDNA-complexed CuNPs (CuNPs@dsDNA) triggered the final signal amplification via real-time conversion of the additive catechol violet (CV) into oligomer or chelation precipitation by CuNPs-tagged reporters. With the proposed setups, a precise and replicable DNA sensing platform for specific target oligo was obtained with a detection limit down to 3.21 femtomolar, demonstrating a beneficial overlapping exploitation of nanomaterials and biochemical reaction as unique SPR infrastructure. Such triple-amplification strategic setups, the possibility of various methods abutment and biocompatibility weight reactor was amassed and adapted to more biological detection field.
•An ultrasensitive SPR sensor of femtomolar-level DNA detection was developed with triple-dual amplification.•CuNPs could be in situ synthesized with the templates of poly-T sequences in dsDNA origami individuals.•Catechol violet was selected as a real-time initiator for mass reply by labeled CuNPs@dsDNA.
We demonstrated the usefulness of Cu light-harvesting plasmonic nanoantennae for the development of inexpensive and efficient artificial organic photoelectric conversion systems. The systems ...consisted of the stacked structures of layers of porphyrin as a dye molecule, oxidation-suppressing layers, and plasmonic Cu arrayed electrodes. To accurately evaluate the effect of Cu nanoantenna on the porphyrin photocurrent, the production of Cu2O by the spontaneous oxidation of the electrode surfaces, which can act as a photoexcited species under visible light irradiation, was effectively suppressed by inserting the ultrathin linking layers consisting of 16-mercaptohexadecanoic acid, titanium oxide, and poly(vinyl alcohol) between the electrode surface and porphyrin molecules. The reflection spectra in an aqueous environment of the arrayed electrodes, which were prepared by thermally depositing Cu on two-dimensional colloidal crystals of silica with diameters of 160, 260, and 330 nm, showed clear reflection dips at 596, 703, and 762 nm, respectively, which are attributed to the excitation of localized surface plasmon resonance (LSPR). While the first dip lies within the wavelengths where the imaginary part of the Cu dielectric function is moderately large, the latter two dips lie within a region of a quite small imaginary part. Consequently, the LSPR excited at the red region provided a particularly large enhancement of porphyrin photocurrent at the Q-band (ca. 59-fold), compared to that on a Cu planar electrode. These results strongly suggest that the plasmonic Cu nanoantennae contribute to the substantial improvement of photoelectric conversion efficiency at the wavelengths, where the imaginary part of the dielectric function is small.
Metallic copper and copper oxide thin films were fabricated on surface of glass slide substrates. Copper oxide thin films were prepared by a hydrothermal method using an α-phase layered hydroxide, ...copper hydroxide nitrate as a precursor. Morphology, thickness and crystallite size of the obtained copper oxide thin films changed by changing the time of hydrothermal treatment. Accordingly, the copper oxide thin films showed various water contact angles and optical band gaps. As, the optical band gap of the nanostructured copper oxide thin films increased with an increase in hydrothermal time from 1.85 to 2.95eV. Moreover, the water contact angles changed from 16.4 to 38.8° by changing the hydrothermal time. By a reductive hydrothermal-treatment route, the copper oxide thin film was reduced to metallic copper thin film without any particle growth.
SEM image of copper oxide thin film (inset shows its contact angle image of surface). Display omitted
•An α-phase layered hydroxide was used to produce copper oxide thin films.•Metallic copper thin film was also produced by a hydrothermal method.•Nano copper oxide thin films showed tunable band gap and wettability.
The intrinsic affinity of DNA molecules toward metallic ions can drive the specific formation of copper nanostructures within the nucleic acid helix structure in a sequence-dependent manner. The ...resultant nanostructures have interesting fluorescent and electrochemical properties, which are attractive for novel biosensing applications. However, the potential of using DNA-templated nano- structures for precision disease diagnosis remains unexplored. Particularly, DNA- templated nanostructures show high potential for the universal amplification-free detection of different RNA biomarker species. Because of their low cellular levels and differing species-dependent length and sequence features, simultaneous detection of different messenger RNAs, microRNAs, and long non-coding RNAs species with a single technique is challenging. Here, we report a contemporary technique for facile in situ assembly of DNA-templated copper nanoblocks （CuNBs） on various RNA species targets after hybridization-based magnetic isolation. Our approach circumvents the typical limitations associated with amplification and labeling procedures of current RNA assays. The synthesized CuNBs enabled amplification-free fM-level RNA detection with flexible fluorescence or electrochemical readouts. Furthermore, our nanosensing technique displays potential for clinical application, as demonstrated by non-invasive analysis of three diagnostic RNA biomarkers from a cohort of 10 prostate cancer patient urinary samples with 100%-concordance （quantitative reverse transcription- polymerase chain reaction （PCR） validation）. The good analytical performance and versatility of our method may be useful in both diagnostics and research fields.
Cu-based nanomaterials have received increasing interest for electrocatalytic applications in the CO2 reduction reaction. However, it is challenging to design nanostructured Cu electrodes to improve ...both the chemical kinetics and molecular transport under the reaction conditions. Here we report on a new type of three-dimensional Cu-based nanostructures as advanced electrocatalysts for CO2 reduction. Driven by thermal oxidation, CuO nanowires and/or porous nanostructures are grown on commercial Cu foams with three-dimensional (3D) frameworks. An electrochemical method is used to reduce CuO to Cu with the structural features largely preserved. The derived Cu-based hierarchical nanostructures demonstrate high catalytic activity and selectivity for CO2 reduction, achieving >80% Faradaic efficiency and ∼3 times enhancement in terms of CO2 conversion rate as compared to the Cu nanowires grown on planar electrodes. Our work highlights the great potential of 3D Cu nanostructures for improving the energy efficiency and power performance of CO2 electrolysis.
Due to the low cost and plasmonic properties existence in the visible range of wavelengths, copper nanostructures are of great interest for Surface-enhanced Raman spectroscopy. In this paper we ...propose a method for synthesizing copper nanostructures by galvanic displacement into the pores of the ion-track SiO2/Si template. The copper deposit morphology grown in a limited volume of SiO2 pores on silicon is studied. The results of electron diffraction indicate that copper deposit contains oxides phases CuO and Cu2O. By using of x-ray photoelectron spectroscopy, chemical composition and elements bonds of SiO2(Cu)/Si system are studied in detail. The possibility of using such structures for Surface-enhanced Raman spectroscopy is discussed.
Abstract Hyperthermia is a cancer treatment strategy that involves raising the temperature of the afflicted tissues without disrupting the surrounding tissues. This study is focused on finite element ...analysis of copper, nanoellipsoids, nanorods, nanospheres and core-shells for potential hyperthermia application. The temperature of copper nanostructures was elevated using an external source to the desired temperature to destroy the cancerous cell. The COMSOL Multiphysics package was used to calculate how long it would take to achieve the desired temperature using different nanostructures of copper. Thermal sensitivity of the tested nanostructures was checked by putting them in a spherical domain of tissue. It was observed that copper nano-rod attained the highest temperature of 43.3 °C compared to other geometries. It was also found that these geometries attained thermal equilibrium just after 0.5 μ s. However, the copper nano-ellipsoid had a higher core volume, which is utilized to determine the thermal sensitivity of the nanostructures. Noble metal (Au) coating was first found to be better than PEG polymer coating for investigating core–shell structures. The Au coating on the surface of the copper core resulted in a gradual decrease in temperature with an increasing volume coverage ratio. These results conclude that copper nanostructures can be suitable candidates for hyperthermia.
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