To accelerate the kinetics of the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells,ultrafine Pt nanoparticles modified with trace amounts of cobalt were fabricated and decorated on carbon black thr...To accelerate the kinetics of the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells,ultrafine Pt nanoparticles modified with trace amounts of cobalt were fabricated and decorated on carbon black through a strategy involving modified glycol reduction and chemical etching.The obtained Pt36Co/C catalyst exhibits a much larger electrochemical surface area(ECSA)and an improved ORR electrocatalytic activity compared to commercial Pt/C.Moreover,an electrode prepared with Pt36Co/C was further evaluated under H2-air single cell test conditions,and exhibited a maximum specific power density of 10.27 W mgPt^-1,which is 1.61 times higher than that of a conventional Pt/C electrode and also competitive with most state-of-the-art Pt-based architectures.In addition,the changes in ECSA,power density,and reacting resistance during the accelerated degradation process further demonstrate the enhanced durability of the Pt36Co/C electrode.The superior performance observed in this work can be attributed to the synergy between the ultrasmall size and homogeneous distribution of catalyst nanoparticles,bimetallic ligand and electronic effects,and the dissolution of unstable Co with the rearrangement of surface structure brought about by acid etching.Furthermore,the accessible raw materials and simplified operating procedures involved in the fabrication process would result in great cost-effectiveness for practical applications of PEMFCs.展开更多
Copper nanoparticles was prepared by ascorbic acid reducing CuC12 solution modified with [ BMIm ] BF4 ionic liquid. The size of copper nanoparticles was obviously affected by the concentration of Cu2+ . The diameter ...Copper nanoparticles was prepared by ascorbic acid reducing CuC12 solution modified with [ BMIm ] BF4 ionic liquid. The size of copper nanoparticles was obviously affected by the concentration of Cu2+ . The diameter of nanoparticles was smaller than 10 nm when the Cu2+ concentration was smaller than 2× 10.2 moL/L. The pH and temperature of reductive reaction had no obvious effect on the size of copper nanoparticles.展开更多
The graphene-gold nanoparticles composite film modified glassy carbon electrode (EG- AuNPs/GCE) was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water wit...The graphene-gold nanoparticles composite film modified glassy carbon electrode (EG- AuNPs/GCE) was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water with differential pulse stripping voltammetry. Such a nanostructured composite film combined with the advantages of gold nanoparticles and graphene, can greatly promote the electron-transfer process and increase accumulation abil-ity for Hg(Ⅱ), leading to a remarkably improved sensitivity. The linear calibration curve ranged from 0.2 μg/L to 30 μg/L for Hg(Ⅱ) and the detection limit (S/N=3) was found to be 0.03 μg/L at a deposition time of 300 s. Moreover, the stablity of the as-prepared electrode and interferences from other substances were evaluated. The modified electrode was successfully applied to the direct detection of Hg(Ⅱ) in real water samples.展开更多
Protein coronas provide the biological identity of nanomaterials in vivo. Here we have used dynamic light scattering (DLS) and transmission electron microscopy (TEM) to investigate the adsorption of serum proteins...Protein coronas provide the biological identity of nanomaterials in vivo. Here we have used dynamic light scattering (DLS) and transmission electron microscopy (TEM) to investigate the adsorption of serum proteins, including bovine serum albumin (BSA), transferrin (TRF) and fibrinogen (FIB), on gold nanoparticles (AuNPs) with different surface modifications (citrate, thioglycolic acid, cysteine, polyethylene glycol (PEG, Mw = 2 k and 5 k)). AuNPs with PEG(5 k) surface modification showed no protein adsorption. AuNPs with non-PEG surface modifications showed aggregation with FIB. AuNPs with citrate and thioglycolic acid surface modifications showed 6-8 nm thick BSA and TRF coronas (corres- ponding to monolayer or bilayer proteins), in which the microscopic dissociation constants of BSA and TRF protein coronas are in the range of 104 to 104 M.展开更多
DNA modified nanoparticles(Au NPs) are an established and widely used type of nucleotide sensor. We sought to improve the design by applying short rigid DNA duplexes near the surface of the Au NPs forming a so called ...DNA modified nanoparticles(Au NPs) are an established and widely used type of nucleotide sensor. We sought to improve the design by applying short rigid DNA duplexes near the surface of the Au NPs forming a so called double-anchored Au NP sensor, and compared it with other conventional DNA modified Au NPs. The improved design exhibited higher assembly efficiency, and consequently increased its sensitivity to target DNA.展开更多
This review reports some recent advances on the use of dendrimer-based systems for cancer therapy. Dendrimers are emerging as promising carriers or stabilizers for drugs and nanoparticles(NPs) due to their highly br...This review reports some recent advances on the use of dendrimer-based systems for cancer therapy. Dendrimers are emerging as promising carriers or stabilizers for drugs and nanoparticles(NPs) due to their highly branched 3-dimensional globular shape, internal hydrophobic cavity and multiple peripheral functional groups. The fabricated nanoplatforms loaded with therapeutic agents such as drugs,siRNAs or NPs can be further modified to have targeting specificity, antifouling properties and good biocompatibility.In particular, recent advances in the surface modifications of dendrimers and the application of dendrimers as versatile platforms for different therapeutic treatments to cancer including chemotherapy, radiotherapy, photothermal therapy,photodynamic therapy, gene therapy, and combination therapy will be introduced in detail.展开更多
Herein, platinum nanoparticles-decorated molybdenum disulfide (PtNPs@MoS2) nanocomposite has been synthesized via a microwave-assisted hydrothermal method, which was characterized by transmission electron microscopy...Herein, platinum nanoparticles-decorated molybdenum disulfide (PtNPs@MoS2) nanocomposite has been synthesized via a microwave-assisted hydrothermal method, which was characterized by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). This MoSz-based nanocomposite modified glass carbon electrode (PtNPs@MoSz/GCE) exhibited excellent electrocatalytic activity toward dopamine (DA) and uric acid (UA) due to their synergistic effect. Two well-defined oxidation peaks of DA and UA were obtained at PtNPs@MoS2/GCE with a large peak separation of 160 mV (DA-UA), sug- gesting that the modified electrode could individually or simultaneously analyze DA and AA. Under the optimal conditions, the peak currents of DA and UA were linearly dependent on their concentrations in the range of 0.5-150 and 5-1000 gmol/L with detection limit of 0.17 and 0.98 gmol/L, respectively. The proposed MoSz-based sensor can also be employed to examine DA and UA in real samples with satisfactory results. Therefore, the PtNPs@MoS2 nanocomposite might offer a good possibil- ity for electrochemical sensing and other electrocatalytic applications.展开更多
基金supported by the National Major Research Project(2016YFB0101208)the National Natural Science Foundation of China(21576257)+1 种基金the Natural Science Foundation-Liaoning United Fund(U1508202)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB06050303)~~
文摘To accelerate the kinetics of the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells,ultrafine Pt nanoparticles modified with trace amounts of cobalt were fabricated and decorated on carbon black through a strategy involving modified glycol reduction and chemical etching.The obtained Pt36Co/C catalyst exhibits a much larger electrochemical surface area(ECSA)and an improved ORR electrocatalytic activity compared to commercial Pt/C.Moreover,an electrode prepared with Pt36Co/C was further evaluated under H2-air single cell test conditions,and exhibited a maximum specific power density of 10.27 W mgPt^-1,which is 1.61 times higher than that of a conventional Pt/C electrode and also competitive with most state-of-the-art Pt-based architectures.In addition,the changes in ECSA,power density,and reacting resistance during the accelerated degradation process further demonstrate the enhanced durability of the Pt36Co/C electrode.The superior performance observed in this work can be attributed to the synergy between the ultrasmall size and homogeneous distribution of catalyst nanoparticles,bimetallic ligand and electronic effects,and the dissolution of unstable Co with the rearrangement of surface structure brought about by acid etching.Furthermore,the accessible raw materials and simplified operating procedures involved in the fabrication process would result in great cost-effectiveness for practical applications of PEMFCs.
文摘Copper nanoparticles was prepared by ascorbic acid reducing CuC12 solution modified with [ BMIm ] BF4 ionic liquid. The size of copper nanoparticles was obviously affected by the concentration of Cu2+ . The diameter of nanoparticles was smaller than 10 nm when the Cu2+ concentration was smaller than 2× 10.2 moL/L. The pH and temperature of reductive reaction had no obvious effect on the size of copper nanoparticles.
文摘The graphene-gold nanoparticles composite film modified glassy carbon electrode (EG- AuNPs/GCE) was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water with differential pulse stripping voltammetry. Such a nanostructured composite film combined with the advantages of gold nanoparticles and graphene, can greatly promote the electron-transfer process and increase accumulation abil-ity for Hg(Ⅱ), leading to a remarkably improved sensitivity. The linear calibration curve ranged from 0.2 μg/L to 30 μg/L for Hg(Ⅱ) and the detection limit (S/N=3) was found to be 0.03 μg/L at a deposition time of 300 s. Moreover, the stablity of the as-prepared electrode and interferences from other substances were evaluated. The modified electrode was successfully applied to the direct detection of Hg(Ⅱ) in real water samples.
文摘Protein coronas provide the biological identity of nanomaterials in vivo. Here we have used dynamic light scattering (DLS) and transmission electron microscopy (TEM) to investigate the adsorption of serum proteins, including bovine serum albumin (BSA), transferrin (TRF) and fibrinogen (FIB), on gold nanoparticles (AuNPs) with different surface modifications (citrate, thioglycolic acid, cysteine, polyethylene glycol (PEG, Mw = 2 k and 5 k)). AuNPs with PEG(5 k) surface modification showed no protein adsorption. AuNPs with non-PEG surface modifications showed aggregation with FIB. AuNPs with citrate and thioglycolic acid surface modifications showed 6-8 nm thick BSA and TRF coronas (corres- ponding to monolayer or bilayer proteins), in which the microscopic dissociation constants of BSA and TRF protein coronas are in the range of 104 to 104 M.
基金supported by the National Basic Research Program of China (2013CB932803)the National Natural Science Foundation of China (91427302, 21421064)the National Natural Science Foundation of China-Deutsche Forschungsgemeinschaft (NSFC-DFG) joint project TRR61
文摘DNA modified nanoparticles(Au NPs) are an established and widely used type of nucleotide sensor. We sought to improve the design by applying short rigid DNA duplexes near the surface of the Au NPs forming a so called double-anchored Au NP sensor, and compared it with other conventional DNA modified Au NPs. The improved design exhibited higher assembly efficiency, and consequently increased its sensitivity to target DNA.
基金financially supported by the Fundamental Research Funds for the Central Universities (for Shi X, Xiong Z, and Shen M)the Science and Technology Commission of Shanghai Municipality (15520711400 and 17540712000)the National Natural Science Foundation of China (81761148028 and 21773026)
文摘This review reports some recent advances on the use of dendrimer-based systems for cancer therapy. Dendrimers are emerging as promising carriers or stabilizers for drugs and nanoparticles(NPs) due to their highly branched 3-dimensional globular shape, internal hydrophobic cavity and multiple peripheral functional groups. The fabricated nanoplatforms loaded with therapeutic agents such as drugs,siRNAs or NPs can be further modified to have targeting specificity, antifouling properties and good biocompatibility.In particular, recent advances in the surface modifications of dendrimers and the application of dendrimers as versatile platforms for different therapeutic treatments to cancer including chemotherapy, radiotherapy, photothermal therapy,photodynamic therapy, gene therapy, and combination therapy will be introduced in detail.
基金the National Basic Research Program of China (2012CB933301)the National Natural Science Foundation of China (21305070, 21475064)+3 种基金the Natural Science Foundation of Jiangsu Province (BK20130861)the Sci-Tech Support Plan of Jiangsu Province (BE2014719)Specialized Research Fund for the Doctoral Program of Higher Education of China (IRT1148, 20133223120013)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Herein, platinum nanoparticles-decorated molybdenum disulfide (PtNPs@MoS2) nanocomposite has been synthesized via a microwave-assisted hydrothermal method, which was characterized by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). This MoSz-based nanocomposite modified glass carbon electrode (PtNPs@MoSz/GCE) exhibited excellent electrocatalytic activity toward dopamine (DA) and uric acid (UA) due to their synergistic effect. Two well-defined oxidation peaks of DA and UA were obtained at PtNPs@MoS2/GCE with a large peak separation of 160 mV (DA-UA), sug- gesting that the modified electrode could individually or simultaneously analyze DA and AA. Under the optimal conditions, the peak currents of DA and UA were linearly dependent on their concentrations in the range of 0.5-150 and 5-1000 gmol/L with detection limit of 0.17 and 0.98 gmol/L, respectively. The proposed MoSz-based sensor can also be employed to examine DA and UA in real samples with satisfactory results. Therefore, the PtNPs@MoS2 nanocomposite might offer a good possibil- ity for electrochemical sensing and other electrocatalytic applications.