Pub Date : 2019-01-01DOI: 10.17104/9783406732133-21
B. Grewe
{"title":"Ökonomie und Gold in Frühgeschichte und Antike","authors":"B. Grewe","doi":"10.17104/9783406732133-21","DOIUrl":"https://doi.org/10.17104/9783406732133-21","url":null,"abstract":"","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77519596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, at first, gold nanorods (GNRs) were synthesized and then they were coated with a layer of hydrogel composed of poly(N-isopropylacrylamide) (PNIPAM) grafted onto carboxymethyl cellulose (CMC) as a backbone. The chemical structure of GNRs/PNIPAM-g-CMC hydrogel was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), atomic-force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The swelling properties of the obtained GNRs/PNIPAM-g-CMC hydrogel were studied at different times and temperatures. In addition, drug release from doxorubicin-loaded GNRs/PNIPAM-g-CMC hydrogel was examined at different temperatures during time. The drug release mechanism was studied by first-order, second-order, and Ritger–Peppas models. Finally, the GNRs/PNIPAM-g-CMC hydrogel biocompatibility was tested against L929 mouse fibroblast cells by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. Our study suggests that GNRs coated with low-cost hydrogels can be excellent candidate for drug delivery systems.
{"title":"Development of a novel thermo-responsive hydrogel-coated gold nanorods as a drug delivery system","authors":"Mehran Kurdtabar, Gazal Baghestani, Ghasem Rezanejade Bardajee","doi":"10.1007/s13404-018-0248-x","DOIUrl":"https://doi.org/10.1007/s13404-018-0248-x","url":null,"abstract":"<p>In this study, at first, gold nanorods (GNRs) were synthesized and then they were coated with a layer of hydrogel composed of poly(<i>N</i>-isopropylacrylamide) (PNIPAM) grafted onto carboxymethyl cellulose (CMC) as a backbone. The chemical structure of GNRs/PNIPAM-g-CMC hydrogel was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), atomic-force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The swelling properties of the obtained GNRs/PNIPAM-g-CMC hydrogel were studied at different times and temperatures. In addition, drug release from doxorubicin-loaded GNRs/PNIPAM-g-CMC hydrogel was examined at different temperatures during time. The drug release mechanism was studied by first-order, second-order, and Ritger–Peppas models. Finally, the GNRs/PNIPAM-g-CMC hydrogel biocompatibility was tested against L929 mouse fibroblast cells by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. Our study suggests that GNRs coated with low-cost hydrogels can be excellent candidate for drug delivery systems.</p>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-018-0248-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4330430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-20DOI: 10.1007/s13404-018-0247-y
Krishna Kanta Haldar, Rathindranath Biswas, Amitava Patra, Krishna Kamal Halder, Tapasi Sen
Photoelectrochemical cell composed of solution-processed nanoflower heterostructure of Au core and eight CdSe petals was investigated for enhanced photocurrent generation. The electrode of CdSe nanorods displayed photocurrent density of 2.1?mA/cm2 whereas the Au core CdSe nanoflower exhibited 4.6?mA/cm2 corresponding to a 119% increase during photoelectrochemical cell performance. Both electrodes showed prompt response to the on/off cycles of light, the photocurrent gain (IPhoton/Idark) in CdSe nanorods is 124.7, while the value is 223.3 for Au/CdSe nanoflower, calculated from the growth-decay curves. Photoresponse time was dramatically improved for Au/CdSe nanoflower samples due to increasing in 66% incident photon-to-current emission. Electron lifetime of 21.63 and 48.71?ns was observed for the electrode of CdSe nanorods and Au/CdSe nanoflowers respectively. The prolonged electron lifetime in the case of the electrode of Au/CdSe nanoflowers was responsible for improving charge separation and as a consequence, higher photocurrent generation.
{"title":"Au/CdSe hybrid nanoflowers: a high photocurrent generating photoelectrochemical cells","authors":"Krishna Kanta Haldar, Rathindranath Biswas, Amitava Patra, Krishna Kamal Halder, Tapasi Sen","doi":"10.1007/s13404-018-0247-y","DOIUrl":"https://doi.org/10.1007/s13404-018-0247-y","url":null,"abstract":"<p>Photoelectrochemical cell composed of solution-processed nanoflower heterostructure of Au core and eight CdSe petals was investigated for enhanced photocurrent generation. The electrode of CdSe nanorods displayed photocurrent density of 2.1?mA/cm<sup>2</sup> whereas the Au core CdSe nanoflower exhibited 4.6?mA/cm<sup>2</sup> corresponding to a 119% increase during photoelectrochemical cell performance. Both electrodes showed prompt response to the on/off cycles of light, the photocurrent gain (<i>I</i><sub>Photon</sub>/<i>I</i><sub>dark</sub>) in CdSe nanorods is 124.7, while the value is 223.3 for Au/CdSe nanoflower, calculated from the growth-decay curves. Photoresponse time was dramatically improved for Au/CdSe nanoflower samples due to increasing in 66% incident photon-to-current emission. Electron lifetime of 21.63 and 48.71?ns was observed for the electrode of CdSe nanorods and Au/CdSe nanoflowers respectively. The prolonged electron lifetime in the case of the electrode of Au/CdSe nanoflowers was responsible for improving charge separation and as a consequence, higher photocurrent generation.</p>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-018-0247-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4803708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-20DOI: 10.1007/s13404-018-0250-3
Panupon Samaimongkol, Hans D. Robinson
We confirm that the unusual purple color of the intermetallic compound AuAl2 is of a plasmonic origin by launching surface plasmons (SPs) in thin AuAl2 films. We measure the SP dispersion relation and also use the films to measure the index of refraction of sucrose solutions using standard SP resonance sensing. We find that the SP energy in planar AuAl2 is approximately 2.1?eV, about 0.4?eV lower than in gold, and the material is highly resistant to oxidation. This is close to what is expected from previously reported measurements of the dielectric function of AuAl2. On this basis, we predict that AuAl2 nanoparticles will a have very strong, spectrally nearly uniform light absorbance about an order of magnitude greater than standard carbon black. Such particles may therefore find applications as obscurants or as an alternative to more complex light-absorbing gold structures in areas such as photothermal therapy or solar steam generation, or in plasmonic catalysis.
{"title":"Launching low-energy surface plasmons in purple gold (AuAl2)","authors":"Panupon Samaimongkol, Hans D. Robinson","doi":"10.1007/s13404-018-0250-3","DOIUrl":"https://doi.org/10.1007/s13404-018-0250-3","url":null,"abstract":"<p>We confirm that the unusual purple color of the intermetallic compound AuAl<sub>2</sub> is of a plasmonic origin by launching surface plasmons (SPs) in thin AuAl<sub>2</sub> films. We measure the SP dispersion relation and also use the films to measure the index of refraction of sucrose solutions using standard SP resonance sensing. We find that the SP energy in planar AuAl<sub>2</sub> is approximately 2.1?eV, about 0.4?eV lower than in gold, and the material is highly resistant to oxidation. This is close to what is expected from previously reported measurements of the dielectric function of AuAl<sub>2</sub>. On this basis, we predict that AuAl<sub>2</sub> nanoparticles will a have very strong, spectrally nearly uniform light absorbance about an order of magnitude greater than standard carbon black. Such particles may therefore find applications as obscurants or as an alternative to more complex light-absorbing gold structures in areas such as photothermal therapy or solar steam generation, or in plasmonic catalysis.</p>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-018-0250-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4807001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-15DOI: 10.1007/s13404-018-0239-y
Lev A. Dykman, Sergey A. Staroverov, Alexander S. Fomin
Gold nanoparticles (AuNPs) are successfully used as an adjuvant in the design of effective vaccines and in the preparation of high-affinity antibodies to haptens and complete antigens. Here, we assessed the adjuvant properties of AuNPs conjugated to a synthetic M2e peptide of the influenza A virus capsid. The resulting conjugate, a commercial influenza vaccine, and M2e in combination with different adjuvants were used to immunize laboratory mice. The highest titer was detected in the sera of mice immunized with two adjuvants: AuNPs and AuNP-conjugated CpG oligodeoxynucleotide 1826. With this combination, we also recorded increases in the respiratory activity of splenic lymphocytes, in the respiratory activity of peritoneal macrophages, and in the production of proinflammatory cytokines (IL-6 and IFN-γ). The results indicate that simultaneous immunization of the animals with two conjugates—M2e + AuNPs and CpG + AuNPs—activates antibody development. Therefore, the use of AuNPs as an antigen carrier leads to a complete and coordinated immune response from both cellular and humoral immunity.
{"title":"Effect of M2e peptide–gold nanoparticle conjugates on development of anti-influenza antibodies","authors":"Lev A. Dykman, Sergey A. Staroverov, Alexander S. Fomin","doi":"10.1007/s13404-018-0239-y","DOIUrl":"https://doi.org/10.1007/s13404-018-0239-y","url":null,"abstract":"<p>Gold nanoparticles (AuNPs) are successfully used as an adjuvant in the design of effective vaccines and in the preparation of high-affinity antibodies to haptens and complete antigens. Here, we assessed the adjuvant properties of AuNPs conjugated to a synthetic M2e peptide of the influenza A virus capsid. The resulting conjugate, a commercial influenza vaccine, and M2e in combination with different adjuvants were used to immunize laboratory mice. The highest titer was detected in the sera of mice immunized with two adjuvants: AuNPs and AuNP-conjugated CpG oligodeoxynucleotide 1826. With this combination, we also recorded increases in the respiratory activity of splenic lymphocytes, in the respiratory activity of peritoneal macrophages, and in the production of proinflammatory cytokines (IL-6 and IFN-γ). The results indicate that simultaneous immunization of the animals with two conjugates—M2e + AuNPs and CpG + AuNPs—activates antibody development. Therefore, the use of AuNPs as an antigen carrier leads to a complete and coordinated immune response from both cellular and humoral immunity.</p>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-018-0239-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4596301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-07DOI: 10.1007/s13404-018-0244-1
Chunli Lu, Peter Majewski
The paper presents an investigation of the synthesis of gold particles on liquid–liquid interfaces using room temperature ionic liquids (RTIL) and ethylene glycol at temperatures up to 180?°C. The results show that depending on the RTIL used, the resulting gold particles are of different shape like trigonal and hexagonal plates, single fibers as well as bundles of fibers, and polyhedral and globular particles. This indicates that the shape of gold particles can be tailored by choosing appropriate RTIL. An increase of processing temperature mainly results in the growth of the particles.
{"title":"Synthesis of gold particles at ionic liquid–ethylene glycol interfaces","authors":"Chunli Lu, Peter Majewski","doi":"10.1007/s13404-018-0244-1","DOIUrl":"https://doi.org/10.1007/s13404-018-0244-1","url":null,"abstract":"<p>The paper presents an investigation of the synthesis of gold particles on liquid–liquid interfaces using room temperature ionic liquids (RTIL) and ethylene glycol at temperatures up to 180?°C. The results show that depending on the RTIL used, the resulting gold particles are of different shape like trigonal and hexagonal plates, single fibers as well as bundles of fibers, and polyhedral and globular particles. This indicates that the shape of gold particles can be tailored by choosing appropriate RTIL. An increase of processing temperature mainly results in the growth of the particles.</p>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2018-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-018-0244-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4285396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}