We synthesize hollow-structured Ag@Au nanoparticles with single porous shell and Ag@Au/Ag@Au double shells by using the galvanic replacement reaction and investigate their linear and nonlinear optical properties. Our ...We synthesize hollow-structured Ag@Au nanoparticles with single porous shell and Ag@Au/Ag@Au double shells by using the galvanic replacement reaction and investigate their linear and nonlinear optical properties. Our results show that the surface plasmon resonance wavelength of the hollow porous nanoparticles could be easily tuned in a wide range in the visible and near infrared region by controlling the volume of HAuCl4. The nonlinear optical refraction of the double-shelled Ag@Au/Ag@Au nanoparticles is prominently enhanced by the plasmon resonance. Our findings may find applications in biosensors and nonlinear optical nanodevices.展开更多
Stretchable and transparent electrodes(STEs)based on silver nanowires(AgNWs)have garnered considerable attention due to their unique optoelectronic features.However,the low oxidation resistance of AgNWs severely limit...Stretchable and transparent electrodes(STEs)based on silver nanowires(AgNWs)have garnered considerable attention due to their unique optoelectronic features.However,the low oxidation resistance of AgNWs severely limits the reliability and durability of devices based on such STEs.The present work reports a type of core-sheath silver@gold nanowires(Ag@Au NWs)with a morphology resembling dual-headed matchsticks and an average Au sheath thickness of 2.5 nm.By starting with such Ag@Au NWs,STEs with an optical transmittance of 78.7%,a haze of 13.0%,a sheet resistance of 13.5Ω·sq.−1,and a maximum tensile strain of 240%can be formed with the aid of capillary-force-induced welding.The resultant STEs exhibit exceptional oxidation resistance,high-temperature resistance,and chemical/electrochemical stability owing to the conformal and dense Au sheath.Furthermore,non-enzymatic glucose biosensors are fabricated employing the Ag@Au NW STEs.The electrocatalytic oxidation currents are proportional to glucose concentrations with a high sensitivity of 967μA·mM−1·cm−2 and a detection limit of 125μM over a detection range of 0.6 to 16 mM.Additionally,the biosensors demonstrate an appealing robustness and antiinterference characteristics,high repeatability,and great stability that make them adequate for practical use.展开更多
Due to the serious harm of diabetes to human health,development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes.Currently,most conventional enzyme-based glu...Due to the serious harm of diabetes to human health,development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes.Currently,most conventional enzyme-based glucose sensors suffer from high cost and low stability due to the inherent defects of natural enzymes.Herein,we develop a pure nanozyme-based glucose detection method using Ag@Au core/shell triangular nanoplates(TNPs),which combines glucose oxidase(GOD)-and horseradish peroxidase(HRP)-like activities of the Au shell and inherent plasmonic properties of Ag TNPs.The sensing mechanism is based on the fact that the Au shell possessed GOD-like activity,enabling the oxidation of glucose to produce H2O2,which can further etch the silver core,leading to the decrease of absorbance at 800 nm and the color change from blue to colorless.Compared with the previous nanozymes-based glucose sensors,our method avoids the use of enzymes and organic chromogenic agent.Moreover,the stability of the Ag@Au core/shell TNPs is much better than that of Ag TNPs due to the protection by the coating of the Au shell.This method was successfully applied to the detection of urine samples from patients with diabetes,indicating its practical applicability for real sample analysis.展开更多
We report an experimental study on the synthesis of metal nanoparticles （NPs） with adjustable optical density based on surface plasmon resonance （SPR）. Metal NPs prepared by laser ablation in liquid method and the...We report an experimental study on the synthesis of metal nanoparticles （NPs） with adjustable optical density based on surface plasmon resonance （SPR）. Metal NPs prepared by laser ablation in liquid method and the effect of laser parameters on the size, distribution, wavelength of SPR of Ag, Au, and mixture of Ag-Au, and Ag core/Au shell NPs are investigated. Our results show that the adjustable SPR band can be achieved in each class of NPs which is suitable for adjustable optical window applications.展开更多
Petrographic and geochemical studies of syenite-looking Ayetoro and Sasaro plutons within Igarra Schist Belt were carried out in order to classify them and determine their tectonic setting and mineralization potential...Petrographic and geochemical studies of syenite-looking Ayetoro and Sasaro plutons within Igarra Schist Belt were carried out in order to classify them and determine their tectonic setting and mineralization potential. Petrographic study and geochemical classification revealed that while Ayetoro boss is microgranite constituting an aggregate of medium grained muscovite, quartz and biotite minerals, Sasaro stock is micromonzonite made up of medium grained albite, orthoclase, biotite, hornblende and pyroxene. Geotectonic setting showed the boss and stock are orogenic, probably derived from the same upper mantle magma as Igarra batholith that got contaminated by crustal materials responsible for their difference in lithology. Their mineralization potential showed that the massive Ayetoro microgranite with no appreciable trace-element contents cannot serve as host of any metallic deposit, and should be suitable for industrial applications. Whereas, the silicified, highly sheared Sasaro monzonite, with elevated level of some trace elements contents as Ag, Au and Cu, could harbor Ag-Au-Cu deposit.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174229,11204221 and 11374236the National Basic Research Program of China under Grant No 2011CB922201
文摘We synthesize hollow-structured Ag@Au nanoparticles with single porous shell and Ag@Au/Ag@Au double shells by using the galvanic replacement reaction and investigate their linear and nonlinear optical properties. Our results show that the surface plasmon resonance wavelength of the hollow porous nanoparticles could be easily tuned in a wide range in the visible and near infrared region by controlling the volume of HAuCl4. The nonlinear optical refraction of the double-shelled Ag@Au/Ag@Au nanoparticles is prominently enhanced by the plasmon resonance. Our findings may find applications in biosensors and nonlinear optical nanodevices.
基金The authors acknowledge financial support from National Natural Science Foundation of China(Nos.52073026 and U20A20264).
文摘Stretchable and transparent electrodes(STEs)based on silver nanowires(AgNWs)have garnered considerable attention due to their unique optoelectronic features.However,the low oxidation resistance of AgNWs severely limits the reliability and durability of devices based on such STEs.The present work reports a type of core-sheath silver@gold nanowires(Ag@Au NWs)with a morphology resembling dual-headed matchsticks and an average Au sheath thickness of 2.5 nm.By starting with such Ag@Au NWs,STEs with an optical transmittance of 78.7%,a haze of 13.0%,a sheet resistance of 13.5Ω·sq.−1,and a maximum tensile strain of 240%can be formed with the aid of capillary-force-induced welding.The resultant STEs exhibit exceptional oxidation resistance,high-temperature resistance,and chemical/electrochemical stability owing to the conformal and dense Au sheath.Furthermore,non-enzymatic glucose biosensors are fabricated employing the Ag@Au NW STEs.The electrocatalytic oxidation currents are proportional to glucose concentrations with a high sensitivity of 967μA·mM−1·cm−2 and a detection limit of 125μM over a detection range of 0.6 to 16 mM.Additionally,the biosensors demonstrate an appealing robustness and antiinterference characteristics,high repeatability,and great stability that make them adequate for practical use.
基金supported by the National Natural Science Foundation of China(No.21876206)the Fundamental Research Funds for the Central Universities(No.18CX02037A)。
文摘Due to the serious harm of diabetes to human health,development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes.Currently,most conventional enzyme-based glucose sensors suffer from high cost and low stability due to the inherent defects of natural enzymes.Herein,we develop a pure nanozyme-based glucose detection method using Ag@Au core/shell triangular nanoplates(TNPs),which combines glucose oxidase(GOD)-and horseradish peroxidase(HRP)-like activities of the Au shell and inherent plasmonic properties of Ag TNPs.The sensing mechanism is based on the fact that the Au shell possessed GOD-like activity,enabling the oxidation of glucose to produce H2O2,which can further etch the silver core,leading to the decrease of absorbance at 800 nm and the color change from blue to colorless.Compared with the previous nanozymes-based glucose sensors,our method avoids the use of enzymes and organic chromogenic agent.Moreover,the stability of the Ag@Au core/shell TNPs is much better than that of Ag TNPs due to the protection by the coating of the Au shell.This method was successfully applied to the detection of urine samples from patients with diabetes,indicating its practical applicability for real sample analysis.
文摘We report an experimental study on the synthesis of metal nanoparticles （NPs） with adjustable optical density based on surface plasmon resonance （SPR）. Metal NPs prepared by laser ablation in liquid method and the effect of laser parameters on the size, distribution, wavelength of SPR of Ag, Au, and mixture of Ag-Au, and Ag core/Au shell NPs are investigated. Our results show that the adjustable SPR band can be achieved in each class of NPs which is suitable for adjustable optical window applications.
文摘Petrographic and geochemical studies of syenite-looking Ayetoro and Sasaro plutons within Igarra Schist Belt were carried out in order to classify them and determine their tectonic setting and mineralization potential. Petrographic study and geochemical classification revealed that while Ayetoro boss is microgranite constituting an aggregate of medium grained muscovite, quartz and biotite minerals, Sasaro stock is micromonzonite made up of medium grained albite, orthoclase, biotite, hornblende and pyroxene. Geotectonic setting showed the boss and stock are orogenic, probably derived from the same upper mantle magma as Igarra batholith that got contaminated by crustal materials responsible for their difference in lithology. Their mineralization potential showed that the massive Ayetoro microgranite with no appreciable trace-element contents cannot serve as host of any metallic deposit, and should be suitable for industrial applications. Whereas, the silicified, highly sheared Sasaro monzonite, with elevated level of some trace elements contents as Ag, Au and Cu, could harbor Ag-Au-Cu deposit.
