Gold Bulletin最新文献

{"title":"Enrichment of placer gold ore through Knelson concentrator optimization","authors":"Çağri Çerik,&nbsp;Gül Akar Şen,&nbsp;Sezai Şen","doi":"10.1007/s13404-024-00352-8","DOIUrl":"10.1007/s13404-024-00352-8","url":null,"abstract":"<div><p>This study investigates the optimization of placer gold ore processing using a laboratory-scale Knelson concentrator through response surface methodology (RSM) and Box-Behnken experimental design. Fifteen experiments were conducted to assess the effects of three parameters: solid concentration (wt.%), G force (G), and fluidization water flow rate (l/min), on gold grade and recovery. Statistical analyses using Design Expert 13 revealed significant quadratic regression equations for both gold grade and recovery, with high coefficients of determination. The empirical models demonstrated the intricate relationships between the concentrator parameters and process responses. Interpretation of the equations revealed that increasing the solid concentration positively influenced gold grade and recovery, while higher G force and fluidization water flow rate negatively impacted these parameters. Moreover, synergistic effects were observed between certain parameter pairs, indicating the complex interplay of factors influencing gold concentration and extraction efficiency. The study highlights the importance of understanding the separation mechanisms within the Knelson concentrator, especially in the presence of flaky gold particles alongside spherical particles. Insights gained from this research provide valuable guidance for optimizing placer gold ore processing operations, ultimately enhancing efficiency and sustainability in mineral processing practices.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 3-4","pages":"107 - 118"},"PeriodicalIF":2.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737069","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}

{"title":"Gelation of Hydrophilic Polymer Bearing Metal-coordination Units with Au(III) Ions: Application to Synthesis of Porous Gold","authors":"Daisuke Nagai,&nbsp;Aoi Mano,&nbsp;Takafumi Ishii,&nbsp;Shusuke Okamoto","doi":"10.1007/s13404-024-00351-9","DOIUrl":"10.1007/s13404-024-00351-9","url":null,"abstract":"<div><p>We describe an environmentally benign method for the synthesis of porous gold by gelation of a hydrophilic polymer bearing metal-coordination units (thiocarbonyl groups, denoted as HPMC) and Au(III) ions. The gelation was performed by dropwise addition of a dispersed aqueous solution of HPMC to an aqueous solution of Au(III) in a test tube. Concentrations of 15 and 20 wt% HPMC provided elongated and fibrous gels. Scanning electron microscopy and transmission electron microscopy analyses of the fibrous gels revealed the formation of porous gels containing Au nanoparticles. Calcination of the polymer parts in the porous gels at 550 °C for 7 h, followed by self-assembly of the remaining Au nanoparticles, provided the golds with micrometer-size pores. Thermogravimetric analysis of the porous golds indicated that its purity was high (96 ~ 99%). Because the metal-coordination unit has soft basic characteristics, it preferentially coordinate to soft acidic noble metal ions such as platinum group metal ions, Ag(I), and so on. Therefore, this method will be applied to synthesis of various porous metals.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 3-4","pages":"79 - 86"},"PeriodicalIF":2.1,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141938657","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}

{"title":"Time-resolved spectroscopic and SERS characterization of plasmonic optical fiber sensor using glutathione-capped gold nanourchins for detection of lead in water","authors":"Mohammad E. Khosroshahi,&nbsp;Christine Gaoiran","doi":"10.1007/s13404-024-00350-w","DOIUrl":"10.1007/s13404-024-00350-w","url":null,"abstract":"<div><p>Fabrication and optical characterization of evanescent plasmonic fiber sensor for detection of Lead (Pb²⁺) ions in water are described. Glutathione-capped gold nanourchins (GNU-GSH) were immobilized onto fluorinated silicon dioxide (SiO₂) clad using (3-Aminopropyl) triethoxysilane (APTES). At 488 and 638 nm Raman wavelength, a penetration depth of 98 and 128 nm was obtained where the sensing region acts as nanoantenna at far-field for detection of analyte. The absorbance of LSPR decreased by time indicating the binding of Pb²⁺ to GSH ligand. Two types of fiber sensors were prepared using 10 and 30 min of GNU incubation time (i.e., F10 and F30) each irradiated in horizontal and vertical configurations. Dynamic SERS study of GNU-GSH-Pb²⁺ showed that F10 and F30 exhibit a similar non-linear response, where the former reached the maximum intensity faster than the latter one. Fluorescence spectroscopy of GNU-GSH in horizontal configuration indicated the maximum emission wavelength of 633 and 605 nm for F10 and F30, respectively. In the vertical configuration, the wavelengths of 607 and 727 nm were observed, respectively, for F10 and F30. When Pb²⁺ was added, a hyperchromic shift of fluorescence occurred from 652 to 655 nm in 2 min for F10, and the intensity decreased linearly by ≈ 72% in 13 min indicating the gradual binding of Pb⁺² ions to GSH sites. In the case of F30, the emission gradually red-shifted from 551 to 569 nm within 15 min, and the emission reached the maximum at 561 nm after 10 min of interaction.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 3-4","pages":"87 - 106"},"PeriodicalIF":2.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871815","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}

{"title":"Ornithine-stabilised gold nanoflowers for label-free sensitive detection of Hg2+ via amalgamation","authors":"Priya Sudhesh,&nbsp;Athira U.S.","doi":"10.1007/s13404-024-00349-3","DOIUrl":"10.1007/s13404-024-00349-3","url":null,"abstract":"<div><p>A simple, eco-friendly method for the synthesis of gold nanoflowers using a non-proteinogenic amino acid is discussed in the present work. Gold nanostructure with unique morphology was synthesized, with the assistance of ornithine amino acid. Ornithine-stabilised gold nanoflowers were found to be highly sensitive towards mercury ions (Hg²⁺) due to Au–Hg amalgamate formation. Due to amalgamate formation, an evolution in morphology of ornithine-stabilised gold nanoflowers happens which can be monitored by the red shift in surface plasmon resonance. Under optimum conditions, our sensor shows a dynamic response range with a detection limit of 6 nM. This developed nanosensor can be used as Hg²⁺ ion sensor in polluted water/waste water by a one-step assay protocol.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 1-2","pages":"1 - 7"},"PeriodicalIF":2.1,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141568960","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}

{"title":"Dioxepine-derived surface-capping gold nanoparticles (Dd-AuNPs) induces ROS-mediated apoptosis and cell cycle arrest in A549 human lung cancer cell line","authors":"Syed Zameer Ahmed Khader,&nbsp;Sidhra Syed Zameer Ahmed,&nbsp;Manthra Raju,&nbsp;Mohamed Rafi Mahboob,&nbsp;Sundarraj Subramaniyan,&nbsp;Abithaa Kaliyannan Rajavel,&nbsp;Kamaraj Chinnaperumal,&nbsp;Dhanush Sakthivel","doi":"10.1007/s13404-024-00348-4","DOIUrl":"10.1007/s13404-024-00348-4","url":null,"abstract":"<div><p>The current study exemplifies the synthesis of novel gold nanoformulations loaded with dioxepine derivative a secondary metabolite from lichen <i>Parmotrema reticulatum</i> utilizing a green approach proving an insight into the impregnation method. The characteristic features of synthesized dioxepine-derived gold NPs (Dd-AuNPs) were analyzed using FT-IR (Fourier Transform Infrared Spectroscopy); it elaborates on the presence of diverse groups with broadband at 3461 cm⁻¹ indicating the presence of the –OH group and the small dip at 2928 cm⁻¹ corresponds to the stretching vibrations of –CH of carbohydrates. The crystallinity of synthesized Dd-AuNPs displayed three distinctive peaks in the 2θ range based on the XRD (X-ray diffraction) pattern. The surface zeta potential of Dd-AuNPs was + 58 mV, which shows the prepared nanoparticle surface has high positive charges and also showed an average hydrodynamic diameter of 661 nm with a peak intensity of 88% using the dynamic light scattering technique. The study elaborates its characterization with SEM (scanning electron microscope) analysis which indicates that AuNPs were dispersed in the solution; as supplementary, the results of HRTEM (high-resolution transmission electron microscopy) were shown at different magnifications along with selected area electron diffraction (SAED) pattern with several morphologies such as spherical, triangular, and hexagonal which particle size ranges from 20 to 30 nm. The synthesized Dd-AuNPs effectively scavenged free radicals in a dose-dependent manner with 21–45% and 12–71% of DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric ion reducing antioxidant power) assay respectively. In addition, in vitro studies exhibited high cytotoxic activity against the human lung cancer cell line (A549) with IC₅₀ value of 12 μg/mL using MTT (3-(4,5-dimethylthiozol-2-yl)-3,5- diphenyl tetrazolium bromide) assay and accompanied by AO/EtBr (acridine orange (AO) and ethidium bromide (EtBr)) and DAPI (4′,6-diamidino-2-phenylindole) staining methods to confirm the apoptosis, nuclear condensation, and fragmentation. Similarly, flow cytometry analysis results provide greater shreds of evidence demonstrating that apoptosis occurred during the S phase, which was further confirmed using caspase assay proving the occurrence of apoptosis. These results highlight the intriguing potential of synthesized Dd-AuNPs as an effective source of bioactive compounds with antioxidant and anticancer abilities, necessitating additional research into their potential therapeutic potential in lung cancer cell lines.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 1-2","pages":"65 - 77"},"PeriodicalIF":2.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529051","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}

{"title":"Facile preparation of gold nanoparticle-decorated chondroitin sulfate composited formulation to reduce osteoporosis in rats with ovariectomies by regulating the microbiota by MAPK signaling pathway.","authors":"Xinyi Guo,&nbsp;Haoyu Feng","doi":"10.1007/s13404-024-00347-5","DOIUrl":"10.1007/s13404-024-00347-5","url":null,"abstract":"<div><p>Osteoporosis represents a prevalent disease that involves the degeneration of bone. The development of potent therapies is desired because the current clinical treatments are not able to provide a satisfying therapeutic effect. Recently, gold (Au) nanomaterials and chondroitin sulfate (CS) have been attracted a lot of attention in the field of drug delivery. The purpose of this research was to investigate exactly CS-AuNP function and its positive influences on anti-osteoporosis in ovariectomized (OVX) rats. The outcome of the OVX rats experimental results revealed effective anti-osteoporosis molecular targets of developed CS-AuNP formulation and their influence on the gut microbiota. Importantly, CS-AuNPs significantly improved lipid profiles, bone microstructure, metabolism markers, and bone mineral density. The findings provide more evidence that CS-AuNPs have effective therapeutic potential in anti-osteoporotic treatment by the MAPK signaling pathway.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 1-2","pages":"49 - 63"},"PeriodicalIF":2.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503406","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}

{"title":"Construction of folate-targeted delivery of polymer-coated gold nanoparticles: investigation of anticancer activity and apoptosis induction in parotid gland carcinoma","authors":"Yanling Wang,&nbsp;Lurui Yu","doi":"10.1007/s13404-024-00346-6","DOIUrl":"10.1007/s13404-024-00346-6","url":null,"abstract":"<div><p>For targeted delivery in the cancer model, this work intends to construct nanoparticles (NPs) using folate (FA)-gemcitabine (GEM)-loaded polyvinylpyrrolidone (PVP)-gold (Au) nanoparticles (GEM@FA/PVP@Au NPs). By precisely assembling the layer, we could construct gemcitabine-loaded FA-functionalized PVP@Au NPs. Various spectroscopical analyses were used and characterized with GEM@FA/PVP@Au NPs. Using MTT assay, wound migration assays, and morphological staining assays, we investigated the antimigratory and anticancer in vitro effects of NPs. To develop GEM@FA/PVP@Au NPs, gemcitabine (40 µg/mL) and folate conjugation onto PVP@Au NPs were added. The NPs demonstrated an 80% release of gemcitabine at acidic pH after their size and charge were incrementally raised by layer-by-layer assembly. Neither the human submandibular gland (HSG) cells and human oral squamous cell carcinoma (HSC-4) cells showed anticancer activity at the concentrations studied for the NPs. In in vitro studies, they inhibited cell migration and had a high apoptosis ratio. The flow cytometry analysis reveals that fabricated nanoparticles effectively kill cancer cells in both cancer cells. These findings indicate the potential of folate-based tumor targeting using GEM/PVP@Au NPs as a safe and effective method for treating parotid gland cancer tumors.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 1-2","pages":"33 - 47"},"PeriodicalIF":2.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13404-024-00346-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the alcohol and water grades on surfactant-free colloidal syntheses of gold nanoparticles in alkaline water-alcohol mixtures","authors":"Jonathan Quinson","doi":"10.1007/s13404-024-00345-7","DOIUrl":"10.1007/s13404-024-00345-7","url":null,"abstract":"<div><p>To make the most of the unique properties of nanomaterials, and to bridge the gap between fundamental and applied research, controlled, green, cheap and energy efficient syntheses of nanoparticles are required. In this respect, room and low temperature surfactant-free colloidal syntheses of nanoparticles obtained in low viscosity and low boiling point solvents, without additives or nature-derived extracts, are promising to develop more active (electro)catalysts. Recently, a room temperature synthesis of surfactant-free gold nanoparticles has been documented (<i>Chem. Mater</i>. 2023, 35, 5, 2173) that requires only water, a base such as NaOH, an alcohol and HAuCl₄. Unfortunately, the syntheses of nanomaterials are often sensitive to multiple parameters and it is well acknowledged that reproducibility is a general challenge in the chemical sciences, where the synthesis of nanomaterials is no exception. Here, we investigate the effect of the water conductivity and solvent grade on the surfactant-free low temperature (ca. 30 °C) synthesis of colloidal gold nanoparticles obtained in alkaline mixtures of ethanol and water. The synthesis can be performed with relatively low-grade ethanol but requires high purity water. The importance of water with low conductivity is also stressed for syntheses where ethylene glycol and glycerol are used as source of reducing agents. The results of this study over 100 samples pave the way to greener, more controlled and scalable syntheses of surfactant-free gold nanomaterials.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 1-2","pages":"27 - 31"},"PeriodicalIF":2.1,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13404-024-00345-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140927228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New dinuclear gold(III) complex with 1,5-naphthyridine as bridging ligand: synthesis, characterization, DNA/BSA binding studies, and anticancer activity","authors":"Snežana Radisavljević,&nbsp;Dušan Ćoćić,&nbsp;Biljana Petrović,&nbsp;Ina Kellner,&nbsp;Ivana Ivanović-Burmazović,&nbsp;Nikola Radenković,&nbsp;Danijela Nikodijević,&nbsp;Milena Milutinović","doi":"10.1007/s13404-024-00344-8","DOIUrl":"10.1007/s13404-024-00344-8","url":null,"abstract":"<div><p>To elucidate an antitumor drug exhibiting enhanced activity relative to cisplatin, a novel dinuclear gold(III) complex was synthesized, incorporating 1,5-naphthyridine as a bridging ligand. Subsequently, the newly synthesized complex underwent comprehensive characterization using various techniques to validate its structural attributes. The stability of the complex in both water and PBS buffer was assessed through UV–Vis spectroscopy. DNA binding studies were conducted employing UV–Vis, fluorescence spectroscopy, and viscosity measurements. Competitive studies with ethidium bromide (EB) or 4′-hydroxyethidium (HOE) were performed utilizing fluorescence spectroscopy. The findings indicated that the dinuclear gold(III) complex interacts with calf thymus DNA (CT-DNA) through a groove binding mode. Moreover, the investigated complex exhibited significant binding constants for its interaction with human serum albumin (HSA) and bovine serum albumin (BSA) and interactions in the presence of site markers (eosin Y or ibuprofen). The dinuclear gold(III) complex demonstrated notable cytotoxicity against HCT116 and MDA-MB-231 cancer cell lines at 24 and 72 h post-treatment. Furthermore, the complex displayed selectivity by inducing significantly lower cytotoxic activity in healthy cells than in cancerous ones. In support of its antitumor activity, the complex exhibited proapoptotic effects, as evidenced by increased caspase 9 activity and low percentages of necrosis. Molecular docking simulations were employed to corroborate all experimentally obtained results.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"57 1-2","pages":"9 - 25"},"PeriodicalIF":2.1,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140598035","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}

{"title":"Unusual selectivity in gold-catalyzed intermolecular Heck reactions","authors":"Mahesh Bhagwan Thoke,&nbsp;Nitin T. Patil","doi":"10.1007/s13404-024-00342-w","DOIUrl":"10.1007/s13404-024-00342-w","url":null,"abstract":"<div><p>The Heck reaction has been considered a robust method for the cross-coupling reaction of olefins and aryl halides to yield alkenes. However, the most significant requirement is the necessity of electronically biased olefins and the requirement of directing group to control the regioselectivity of the Heck reaction. The research group of Patil and Gandon recently documented the gold-catalyzed Heck reaction, demonstrating the utilization of simple aliphatic alkenes as substrates. This approach does not need electronically biased olefins and offers a distinct regioselectivity when compared to the Heck reaction catalyzed by other transition metal catalysts.</p></div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"56 4","pages":"159 - 165"},"PeriodicalIF":2.1,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140302592","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}