Our study producted Polydopamine modified gold nanoflowers with controlled morphology for anti-tumor photothermal therapy.The branch structure containsabundant(Au NFs).By adjusting the reduction rate,the dosage of red...Our study producted Polydopamine modified gold nanoflowers with controlled morphology for anti-tumor photothermal therapy.The branch structure containsabundant(Au NFs).By adjusting the reduction rate,the dosage of reducing agent(sodium borohydride)and the reduction temperature,we can adjust tthe morphology and particle size of Au NFs.We found that the lower reaction temperature is,the more abundant the surface branching structure of gold nanoflowers is,by adjusting the reaction temperature.and the largest specific surface area of golden nanopowder was found at 0℃.The results of TEM indicated that with the increase of sodium borohydride,the diameter of gold nano flowers gold nanoflowers decreased and was in the range of 60~100nm,and it has good EPR effect After that,we modify poly(dopamine)(PDA)biomimetic layer on the surface of golden nanoparticles to obtain Au NFS@PDA.Poly(dopamine)has the ability,of photothermal conversion,which can enhance the plasma resonance ability and biocompatibility of gold nanoflowers in the near infrared region.We can control the thickness of polydopamine layer on the surface of gold nanoflowers between 7~15nm by adjusting dopamine DA concentrationgold nanoflowers.Au NFS@PDA was characterized by its morphology and physical properties.We detect(UV-Vis)spectra in the near infrared region.And it showed obvious absorption peaks in the near infrared region of 575~650nm.Under the 808nm irradiation laser,the photothermal conversion of gold nanoflowers and polydopamine can be rapidly increased to 57°C.Fourier Transform Infrared Absorption Spectroscopy(FTIR)and X-ray Diffraction(XRD)analysis showed that polydopamine was modified successfully,Au NFS@PDA and Au NFs had no obvious difference in crystal form.The cell viability test showed that the bionic Au NFS@PDA had good biocompatibility and showed good antitumor activity against HeLa cells under NIR irradiation.The cell viability was only 12%.Therefore,we can use Au NFS@PDA with good biocompatibility as a promising photothermal conversion agent in tumor therapy.展开更多
By binding molecular probes that target tumor cells, gold nanoparticles （AuNPs） with superior characteristics have shown great potential in tumor molecular imaging studies. The non-invasive, high-resolution, and thr...By binding molecular probes that target tumor cells, gold nanoparticles （AuNPs） with superior characteristics have shown great potential in tumor molecular imaging studies. The non-invasive, high-resolution, and three-dimensional imaging of the targeted AuNPs within the tumor is desirable for both diagnosis and therapy. In this study, gold nanoflowers （AuNFs） are presented as a novel contrast agent for photoacoustic tomography （PAT）. By binding to folic acid, the molecular probe, the tail-vein injected AuNFs concentrated within the tumor site in mice; this was clearly visualized by three-dimensional （3D） PAT imaging. In addition, toxicity assay proved that AuNFs were harmless to living cells and animals. Our results demonstrate that AuNFs have great potential in tumor molecular imaging.展开更多
We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal ...We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal enhancement. We further found that iodide ions （I^-） could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance （LSPR） bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I^-.展开更多
Facile synthesis of multi-branched gold nanostructures by using the tetrabutyl ammonium bromide （TBAB） as a capping agent is described. The reaction is carried out in a one-step process at mild temperature. Gold nan...Facile synthesis of multi-branched gold nanostructures by using the tetrabutyl ammonium bromide （TBAB） as a capping agent is described. The reaction is carried out in a one-step process at mild temperature. Gold nanostructures with more than six sharp branches ranging from 70 to 130 nm in length are synthesized in high yield. It is proposed that the relative weak adsorption capacity of TBAB leads to the incompletely covered gold surface and the growth of nanoparticles occurs on the uncovered gold surface, and therefore short branches appear consequently. Then positively charged TBAB layers on the gold surfaces prevent the branches from aggregating with each other which stimulates the branch growth. The prepared branched gold nanoparticles show efficient surface-enhanced Raman scattering （SERS） properties. Low temperature （4 ℃） is unfavorable to the formation of multi-branched gold nanostructures, and only thin small irregular plate-like nanoparticles are produced. The addition of SDS in TBAB aqueous solution results in forming SDS micelles at much lower concentration of SDS （0.4 mmol/L） as compared to that in pure water, and short branched gold nanoparticles are obtained in the SDS-TBAB system.展开更多
A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber m...A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.展开更多
文摘Our study producted Polydopamine modified gold nanoflowers with controlled morphology for anti-tumor photothermal therapy.The branch structure containsabundant(Au NFs).By adjusting the reduction rate,the dosage of reducing agent(sodium borohydride)and the reduction temperature,we can adjust tthe morphology and particle size of Au NFs.We found that the lower reaction temperature is,the more abundant the surface branching structure of gold nanoflowers is,by adjusting the reaction temperature.and the largest specific surface area of golden nanopowder was found at 0℃.The results of TEM indicated that with the increase of sodium borohydride,the diameter of gold nano flowers gold nanoflowers decreased and was in the range of 60~100nm,and it has good EPR effect After that,we modify poly(dopamine)(PDA)biomimetic layer on the surface of golden nanoparticles to obtain Au NFS@PDA.Poly(dopamine)has the ability,of photothermal conversion,which can enhance the plasma resonance ability and biocompatibility of gold nanoflowers in the near infrared region.We can control the thickness of polydopamine layer on the surface of gold nanoflowers between 7~15nm by adjusting dopamine DA concentrationgold nanoflowers.Au NFS@PDA was characterized by its morphology and physical properties.We detect(UV-Vis)spectra in the near infrared region.And it showed obvious absorption peaks in the near infrared region of 575~650nm.Under the 808nm irradiation laser,the photothermal conversion of gold nanoflowers and polydopamine can be rapidly increased to 57°C.Fourier Transform Infrared Absorption Spectroscopy(FTIR)and X-ray Diffraction(XRD)analysis showed that polydopamine was modified successfully,Au NFS@PDA and Au NFs had no obvious difference in crystal form.The cell viability test showed that the bionic Au NFS@PDA had good biocompatibility and showed good antitumor activity against HeLa cells under NIR irradiation.The cell viability was only 12%.Therefore,we can use Au NFS@PDA with good biocompatibility as a promising photothermal conversion agent in tumor therapy.
文摘By binding molecular probes that target tumor cells, gold nanoparticles （AuNPs） with superior characteristics have shown great potential in tumor molecular imaging studies. The non-invasive, high-resolution, and three-dimensional imaging of the targeted AuNPs within the tumor is desirable for both diagnosis and therapy. In this study, gold nanoflowers （AuNFs） are presented as a novel contrast agent for photoacoustic tomography （PAT）. By binding to folic acid, the molecular probe, the tail-vein injected AuNFs concentrated within the tumor site in mice; this was clearly visualized by three-dimensional （3D） PAT imaging. In addition, toxicity assay proved that AuNFs were harmless to living cells and animals. Our results demonstrate that AuNFs have great potential in tumor molecular imaging.
基金supported by the National Natural Science Foundation of China (21305113)the Chongqing Fundamental and Advanced Research Project (cstc2013jcyjA50008)+2 种基金the Fundamental Research Funds for the Central Universities (XDJK2015B029)the fund of State Key Laboratory of Electroanalytical Chemistry (Changchun Institute of Applied Chemistry, Chinese Academy of Sciences) (SKLEAC201312)the Research Fund for the Doctor Program of Southwest University (swu111077)
文摘We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal enhancement. We further found that iodide ions （I^-） could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance （LSPR） bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I^-.
基金Project supported by the National Natural Science Foundation of China （Nos. 50872042, 51003040）, Open Research Project （No. KF0802） from State Key Laboratory of Crystal Material （Shandong University） and the Special Fund for Postdoctoral Innovation Program of Shandong Province （No. 200703075）.
文摘Facile synthesis of multi-branched gold nanostructures by using the tetrabutyl ammonium bromide （TBAB） as a capping agent is described. The reaction is carried out in a one-step process at mild temperature. Gold nanostructures with more than six sharp branches ranging from 70 to 130 nm in length are synthesized in high yield. It is proposed that the relative weak adsorption capacity of TBAB leads to the incompletely covered gold surface and the growth of nanoparticles occurs on the uncovered gold surface, and therefore short branches appear consequently. Then positively charged TBAB layers on the gold surfaces prevent the branches from aggregating with each other which stimulates the branch growth. The prepared branched gold nanoparticles show efficient surface-enhanced Raman scattering （SERS） properties. Low temperature （4 ℃） is unfavorable to the formation of multi-branched gold nanostructures, and only thin small irregular plate-like nanoparticles are produced. The addition of SDS in TBAB aqueous solution results in forming SDS micelles at much lower concentration of SDS （0.4 mmol/L） as compared to that in pure water, and short branched gold nanoparticles are obtained in the SDS-TBAB system.
基金the National Natural Science Foundation of China (Nos. 21775097 and 21804106)the China Postdoctoral Science Foundation (No. 2017M620444)the Fundamental Research Funds for the Central Universities (Nos. XJJ2018247 and GK201801006)
文摘A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.
