Wedelia chinensis is a medicinal herb of the family Asteraceae. Green synthesis of silver nanoparticles (AgNPs) was done by using flower extract of Wedelia chinensis. Optimum conditions for AgNPs synthesis were as such: flower extract and AgNO3 (0.1 M) were taken in 1:9 ratio; temperature- 30 °C; reaction time- 12 h. UV-Visible spectra of the synthesized nanoparticle showed maximum absorption at 400 nm. Crystalline nature of silver nanoparticle was confirmed by XRD pattern. Through TEM, average size of AgNPs was observed as 51.2 nm. FTIR indicated participation of various functional groups of flower extract in the formation of nanoparticles. In DLS study, AgNPs of size 121 nm showed 100% intensity. Zeta potential was recorded as −1.24 mV. Strong peak of silver was observed in EDX study. AgNPs alone showed effective inhibition against all pathogenic bacteria taken as test organisms, but its combination with the antibiotics showed considerable enhancement in antibacterial activity. Inhibition for methicillin resistant Staphylococcus aureus (MRSA) was maximum when nanoparticles were taken in the combination of antibiotics and the extract. Significant antioxidant potential of AgNPs were observed in DPPH, ascorbic acid and DNA nicking assays. Thus, AgNPs of Wedelia chinensis flower extract showed significant medicinal efficacy as antioxidant and antibacterial.
{"title":"Biogenic synthesis of silver nanoparticle from flower extract of Wedelia chinensis and their antibacterial and antioxidant activity","authors":"Brajesh Chandra Pandey, Ashish Gupta, Alakh Niranjan Sahu, Riddha Dey, Richa Raghuwanshi and Nishi Kumari","doi":"10.1088/2632-959x/ad54df","DOIUrl":"https://doi.org/10.1088/2632-959x/ad54df","url":null,"abstract":"Wedelia chinensis is a medicinal herb of the family Asteraceae. Green synthesis of silver nanoparticles (AgNPs) was done by using flower extract of Wedelia chinensis. Optimum conditions for AgNPs synthesis were as such: flower extract and AgNO3 (0.1 M) were taken in 1:9 ratio; temperature- 30 °C; reaction time- 12 h. UV-Visible spectra of the synthesized nanoparticle showed maximum absorption at 400 nm. Crystalline nature of silver nanoparticle was confirmed by XRD pattern. Through TEM, average size of AgNPs was observed as 51.2 nm. FTIR indicated participation of various functional groups of flower extract in the formation of nanoparticles. In DLS study, AgNPs of size 121 nm showed 100% intensity. Zeta potential was recorded as −1.24 mV. Strong peak of silver was observed in EDX study. AgNPs alone showed effective inhibition against all pathogenic bacteria taken as test organisms, but its combination with the antibiotics showed considerable enhancement in antibacterial activity. Inhibition for methicillin resistant Staphylococcus aureus (MRSA) was maximum when nanoparticles were taken in the combination of antibiotics and the extract. Significant antioxidant potential of AgNPs were observed in DPPH, ascorbic acid and DNA nicking assays. Thus, AgNPs of Wedelia chinensis flower extract showed significant medicinal efficacy as antioxidant and antibacterial.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-13DOI: 10.1088/2632-959x/ad5221
Hong Son Nguyen, Van Hoang Nguyen, Thi Thu Huong Nguyen, Ngoc Toan Vu and Ngoc Hoan Le
In this study, we introduce a synthesis process of bimetallic nanoparticles (BNPs) Fe/Ni and Fe/Cu utilizing concentrated Camellia sinenis extract that was optimized with a solvent ratio of ethanol/H2O 4/1 (v/v), a metal ratio of 5/1 (w/w), a total polyphenol content (TPC) in the solution of 12.5 g.l−1, pH = 3–4, 25 °C, and the reaction time ranging from 30 min to 50 min. The structural and morphological characteristics of the resulting materials were determined using several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The maximum removal efficiency of methylene blue (MB) by BNPs Fe/Ni and Fe/Cu materials was found to be 88.60% and 91.06%, respectively, at a concentration of MB = 25 mg.l−1 and 25 °C. According to the results of the kinetic modeling study, the adsorption process of MB on the two BNPs materials followed second-order kinetics, with the maximum adsorption capacities of MB on Fe/Ni and Fe/Cu BNPs being 26.94 mg.g−1and 28.00 mg.g−1, respectively.
{"title":"Optimization of Fe/Ni, Fe/Cu bimetallic nanoparticle synthesis process utilizing concentrated Camellia sinensis extract solution and activity evaluation through methylene blue removal reaction","authors":"Hong Son Nguyen, Van Hoang Nguyen, Thi Thu Huong Nguyen, Ngoc Toan Vu and Ngoc Hoan Le","doi":"10.1088/2632-959x/ad5221","DOIUrl":"https://doi.org/10.1088/2632-959x/ad5221","url":null,"abstract":"In this study, we introduce a synthesis process of bimetallic nanoparticles (BNPs) Fe/Ni and Fe/Cu utilizing concentrated Camellia sinenis extract that was optimized with a solvent ratio of ethanol/H2O 4/1 (v/v), a metal ratio of 5/1 (w/w), a total polyphenol content (TPC) in the solution of 12.5 g.l−1, pH = 3–4, 25 °C, and the reaction time ranging from 30 min to 50 min. The structural and morphological characteristics of the resulting materials were determined using several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The maximum removal efficiency of methylene blue (MB) by BNPs Fe/Ni and Fe/Cu materials was found to be 88.60% and 91.06%, respectively, at a concentration of MB = 25 mg.l−1 and 25 °C. According to the results of the kinetic modeling study, the adsorption process of MB on the two BNPs materials followed second-order kinetics, with the maximum adsorption capacities of MB on Fe/Ni and Fe/Cu BNPs being 26.94 mg.g−1and 28.00 mg.g−1, respectively.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-11DOI: 10.1088/2632-959x/ad52b3
Zeineb Ayed, Nathaniel Davis and Renee V Goreham
The escalating issue of antibiotic resistance in bacteria necessitates innovative detection methods to identify resistance mechanisms promptly. In this study, we present a novel approach for detecting resistance in Pseudomonas aeruginosa, a bacterium known for its metallo-β-lactamase production during the development of antibiotic resistance. We have designed an aptasensor employing Förster resonance energy transfer utilising two distinct methodologies. Initially, indium phosphide quantum dots with a zinc sulphide shell, and gold nanoparticles were utilised as the Förster resonance energy transfer donor-acceptor pair. Although this system demonstrated a response, the efficiency was low. Subsequently, optimisation involved relocating the donor and acceptor in close proximity and incorporating two quantum dots with varying emission wavelengths as the acceptor and donor. This optimisation significantly enhanced the Förster resonance efficiency, resulting in a novel method for detecting metallo-β-lactamase. Förster resonance energy transfer efficiency was increased from 31% to 63% by optimising the distance and donor using a quantum dot-quantum dot pair. Our findings showcase a cheap, rapid and versatile aptasensor with potential applications beyond antibiotic resistance, highlighting its adaptability for diverse scenarios.
{"title":"Development of an aptasensor to target metallo-β-lactamase through Förster resonance energy transfer","authors":"Zeineb Ayed, Nathaniel Davis and Renee V Goreham","doi":"10.1088/2632-959x/ad52b3","DOIUrl":"https://doi.org/10.1088/2632-959x/ad52b3","url":null,"abstract":"The escalating issue of antibiotic resistance in bacteria necessitates innovative detection methods to identify resistance mechanisms promptly. In this study, we present a novel approach for detecting resistance in Pseudomonas aeruginosa, a bacterium known for its metallo-β-lactamase production during the development of antibiotic resistance. We have designed an aptasensor employing Förster resonance energy transfer utilising two distinct methodologies. Initially, indium phosphide quantum dots with a zinc sulphide shell, and gold nanoparticles were utilised as the Förster resonance energy transfer donor-acceptor pair. Although this system demonstrated a response, the efficiency was low. Subsequently, optimisation involved relocating the donor and acceptor in close proximity and incorporating two quantum dots with varying emission wavelengths as the acceptor and donor. This optimisation significantly enhanced the Förster resonance efficiency, resulting in a novel method for detecting metallo-β-lactamase. Förster resonance energy transfer efficiency was increased from 31% to 63% by optimising the distance and donor using a quantum dot-quantum dot pair. Our findings showcase a cheap, rapid and versatile aptasensor with potential applications beyond antibiotic resistance, highlighting its adaptability for diverse scenarios.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-11DOI: 10.1088/2632-959x/ad52b4
Abubakar A Sifawa, Sabah M Mohammad, A Muhammad, Shireen Mohammed Abed and Way Foong Lim
This study investigates the influence of different annealing ambient on terbium oxide (Tb4O7) passivation layers sputtered using radio frequency (RF) sputtering on silicon (Si) substrates. The passivation layers were subjected to annealing in various ambient, including oxygen (O2), nitrogen (N2), argon (Ar), and nitrogen-oxygen-nitrogen (NON). The structural, morphological, compositional, topological, and optical properties of the passivation layers were characterized using various techniques. The obtained results indicate that the annealing ambient has a significant impact on the properties of Tb4O7 passivation layers. Annealing in Ar ambient leads to the formation of Tb4O7 with improved crystallinity close to 49.75 nm and higher surface roughness at (2.32 nm). In contrast, annealing in the O2 ambient results in broad GIXRD peaks with the lowest surface roughness around (1.34 nm). Notably, annealing in N2 ambient exhibits an intermediate behavior, with partial crystallized size values (31.80 nm) compared to the Tb4O7 passivation layer annealed in Ar ambient and moderate surface roughness. The optical bandgap (Eg) was estimated by applying the Kubelka–Munk (KM) approach and the obtained values were 3.28, 3.17, 2.37, and 2.27 eV for annealed in O2, N2, Ar, and NON ambients, respectively. The investigation of Tb4O7 as a passivation material expands the range of materials available for semiconductor device fabrication, offering potential advancements in optoelectronics applications. Therefore, the significance of this study lies in its contribution to the optimization of Tb4O7 passivation layers in the field of semiconductor device technology. Hence, the sample annealed in an Ar ambient demonstrated the best results in terms of structural, morphological, compositional, topological, and optical properties of Tb4O7 passivation layers as compared to other samples.
{"title":"Influence of different annealing ambient on terbium oxide passivation layers sputtered using the RF sputtering on silicon substrate","authors":"Abubakar A Sifawa, Sabah M Mohammad, A Muhammad, Shireen Mohammed Abed and Way Foong Lim","doi":"10.1088/2632-959x/ad52b4","DOIUrl":"https://doi.org/10.1088/2632-959x/ad52b4","url":null,"abstract":"This study investigates the influence of different annealing ambient on terbium oxide (Tb4O7) passivation layers sputtered using radio frequency (RF) sputtering on silicon (Si) substrates. The passivation layers were subjected to annealing in various ambient, including oxygen (O2), nitrogen (N2), argon (Ar), and nitrogen-oxygen-nitrogen (NON). The structural, morphological, compositional, topological, and optical properties of the passivation layers were characterized using various techniques. The obtained results indicate that the annealing ambient has a significant impact on the properties of Tb4O7 passivation layers. Annealing in Ar ambient leads to the formation of Tb4O7 with improved crystallinity close to 49.75 nm and higher surface roughness at (2.32 nm). In contrast, annealing in the O2 ambient results in broad GIXRD peaks with the lowest surface roughness around (1.34 nm). Notably, annealing in N2 ambient exhibits an intermediate behavior, with partial crystallized size values (31.80 nm) compared to the Tb4O7 passivation layer annealed in Ar ambient and moderate surface roughness. The optical bandgap (Eg) was estimated by applying the Kubelka–Munk (KM) approach and the obtained values were 3.28, 3.17, 2.37, and 2.27 eV for annealed in O2, N2, Ar, and NON ambients, respectively. The investigation of Tb4O7 as a passivation material expands the range of materials available for semiconductor device fabrication, offering potential advancements in optoelectronics applications. Therefore, the significance of this study lies in its contribution to the optimization of Tb4O7 passivation layers in the field of semiconductor device technology. Hence, the sample annealed in an Ar ambient demonstrated the best results in terms of structural, morphological, compositional, topological, and optical properties of Tb4O7 passivation layers as compared to other samples.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Metformin, an anti-hypoglycemic medication, has been used for decades due to its efficiency and is the most consumed pharmaceutical drug worldwide. Consequently, monitoring its concentration in environmental water is important due to its suspected effect on human health and aquatic life. This study reported the extraction, preconcentration, separation and determination of metformin (MET) in waters. Dispersive solid phase extraction (dSPE) using UiO-66@Fe3O4 nanocomposite as a sorbent was used to extract and preconcentrate MET. The high-performance liquid chromatography-diode array detector (HPLC-DAD) achieved the separation and quantification of MET in the samples. Experiemental design was used to optimise influential variables in the extraction and preconcentration of MET. The linearity, limit of detection (LOD) and limit of quantification (LOQ) for MET were 0.5–100 μg L−1 (R2 = 0.9987), 0.16 μg L−1 and 0.53 μg L−1, respectively. The intraday (n = 10 same-day replicates) and interday (n = 5 consecutive days) precisions reported as relative standard deviations (RSD %) were less than 5%. The accuracy of the method expressed as percentage recovery (%R) ranged from 84 to 112%. The method was applied to extract and preconcentrate MET in wastewater and river water samples. The MET was detected in greater concentrations in wastewater than in river water samples. The validation based on specificity, trueness, linearity, precision, and application to the analysis of MET in real samples showed that the combination of dSPE and HPLC-DAD methods is applicable for MET monitoring in surface water and wastewater. Furthermore, the dSPE/HPLC-DAD method was rapid, simple and suitable for estimating the concentrations of MET in South African surface water and wastewater for the first time. Lastly, the environmental risk caused by the occurrence of MET in surface water was investigated in terms of hazard quotient (HQ). The HQ values were less than unity, suggesting a low possibility risk for the aquatic organisms.
二甲双胍是一种降血糖药物，因其高效而被使用了几十年，是全球消费量最大的药物。因此，由于二甲双胍可能对人类健康和水生生物产生影响，对其在环境水体中的浓度进行监测非常重要。本研究报告了水体中二甲双胍（MET）的萃取、预浓缩、分离和测定。以 UiO-66@Fe3O4 纳米复合材料为吸附剂，采用分散固相萃取（dSPE）对二甲双胍进行萃取和预浓缩。高效液相色谱-二极管阵列检测器（HPLC-DAD）实现了样品中 MET 的分离和定量。实验设计用于优化 MET 提取和预浓缩过程中的影响变量。MET 的线性相关系数、检出限（LOD）和定量限（LOQ）分别为 0.5-100 μg L-1 (R2 = 0.9987)、0.16 μg L-1 和 0.53 μg L-1。以相对标准偏差（RSD %）表示的日内（n = 10 个同日重复）和日间（n = 5 个连续日）精确度均小于 5%。以回收率 (%R) 表示的方法准确度在 84% 到 112% 之间。该方法适用于提取和预浓缩废水和河水样品中的 MET。废水中 MET 的检测浓度高于河水样品。基于特异性、真实性、线性、精密度和实际样品中 MET 分析应用的验证表明，dSPE 和 HPLC-DAD 方法组合适用于地表水和废水中 MET 的监测。此外，dSPE/HPLC-DAD 方法快速、简单，首次适用于估算南非地表水和废水中 MET 的浓度。最后，从危害商数（HQ）的角度研究了地表水中出现 MET 所造成的环境风险。HQ 值小于 1，表明对水生生物的可能性风险较低。
{"title":"UiO-66@Fe3O4 nanocomposite as an adsorbent in dispersive solid phase extraction of metformin in surface water and wastewater","authors":"Abigail Goitumetswe Sekopelo, Tshimangadzo Saddam Munonde, Azile Nqombolo, Anele Mpupa and Philiswa Nosizo Nomngongo","doi":"10.1088/2632-959x/ad461c","DOIUrl":"https://doi.org/10.1088/2632-959x/ad461c","url":null,"abstract":"Metformin, an anti-hypoglycemic medication, has been used for decades due to its efficiency and is the most consumed pharmaceutical drug worldwide. Consequently, monitoring its concentration in environmental water is important due to its suspected effect on human health and aquatic life. This study reported the extraction, preconcentration, separation and determination of metformin (MET) in waters. Dispersive solid phase extraction (dSPE) using UiO-66@Fe3O4 nanocomposite as a sorbent was used to extract and preconcentrate MET. The high-performance liquid chromatography-diode array detector (HPLC-DAD) achieved the separation and quantification of MET in the samples. Experiemental design was used to optimise influential variables in the extraction and preconcentration of MET. The linearity, limit of detection (LOD) and limit of quantification (LOQ) for MET were 0.5–100 μg L−1 (R2 = 0.9987), 0.16 μg L−1 and 0.53 μg L−1, respectively. The intraday (n = 10 same-day replicates) and interday (n = 5 consecutive days) precisions reported as relative standard deviations (RSD %) were less than 5%. The accuracy of the method expressed as percentage recovery (%R) ranged from 84 to 112%. The method was applied to extract and preconcentrate MET in wastewater and river water samples. The MET was detected in greater concentrations in wastewater than in river water samples. The validation based on specificity, trueness, linearity, precision, and application to the analysis of MET in real samples showed that the combination of dSPE and HPLC-DAD methods is applicable for MET monitoring in surface water and wastewater. Furthermore, the dSPE/HPLC-DAD method was rapid, simple and suitable for estimating the concentrations of MET in South African surface water and wastewater for the first time. Lastly, the environmental risk caused by the occurrence of MET in surface water was investigated in terms of hazard quotient (HQ). The HQ values were less than unity, suggesting a low possibility risk for the aquatic organisms.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140934884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-09DOI: 10.1088/2632-959x/ad437a
Ganganapalli Gousiya Bhanu, B Manmadha Rao
BaTiO3 nanostructures have been considered as a promising candidates in recent past for energy and biomedical sectors owing to their excellent physiochemical properties, such as high dielectric constant, excellent piezoelectric property, good biocompatibility, non-linear optical characteristics etc. Present study reveals on free-standing arrays of BaTiO3 nanostructures, were fabricated by hydrothermal conversion of anodic TiO2 nanotubes. Morphological and structural information of the BaTiO3 nanotubes were done using FESEM and XRD studies. FESEM analysis revealed that the fabricated samples were having tubular morphology of average length and pore diameter of 4.63 μm and 290 nm respectively. Cubical perovskite crystalline phase of BaTiO3 was confirmed through XRD analysis. The BaTiO3 nanotube samples had shown a higher sensitivity of 44.43 μA mM−1 cm−2 and a faster response of 0.1 s for glucose detection. The fabricated BaTiO3 nanotubes film also showed a higher contact angle of 122.70°. Therefore, our present fabrication on Titanium foil study emphasizes on arrays of BaTiO3 nanotubes which will open up a new window in the development of various types of sensing and hydrophobic coating applications.
{"title":"Free-standing arrays of BaTiO3 nanotubes for non-enzymatic glucose sensing & hydrophobic coating applications","authors":"Ganganapalli Gousiya Bhanu, B Manmadha Rao","doi":"10.1088/2632-959x/ad437a","DOIUrl":"https://doi.org/10.1088/2632-959x/ad437a","url":null,"abstract":"BaTiO<sub>3</sub> nanostructures have been considered as a promising candidates in recent past for energy and biomedical sectors owing to their excellent physiochemical properties, such as high dielectric constant, excellent piezoelectric property, good biocompatibility, non-linear optical characteristics etc. Present study reveals on free-standing arrays of BaTiO<sub>3</sub> nanostructures, were fabricated by hydrothermal conversion of anodic TiO<sub>2</sub> nanotubes. Morphological and structural information of the BaTiO<sub>3</sub> nanotubes were done using FESEM and XRD studies. FESEM analysis revealed that the fabricated samples were having tubular morphology of average length and pore diameter of 4.63 <italic toggle=\"yes\">μ</italic>m and 290 nm respectively. Cubical perovskite crystalline phase of BaTiO<sub>3</sub> was confirmed through XRD analysis. The BaTiO<sub>3</sub> nanotube samples had shown a higher sensitivity of 44.43 <italic toggle=\"yes\">μ</italic>A mM<sup>−1</sup> cm<sup>−2</sup> and a faster response of 0.1 s for glucose detection. The fabricated BaTiO<sub>3</sub> nanotubes film also showed a higher contact angle of 122.70°. Therefore, our present fabrication on Titanium foil study emphasizes on arrays of BaTiO<sub>3</sub> nanotubes which will open up a new window in the development of various types of sensing and hydrophobic coating applications.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140934882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plant mediated synthesis of silver nanoparticles is eco-friendly and of low cost. The synthesis involves a reduction of silver ions and is controlled by several independent factors. In this work, silver nanoparticles (AgNPs) were successfully synthesized using olive stone extract (OSE) and olive mill wastewater (OMW) extract. The nanoparticle synthesis was monitored using the plasmon resonance observed in the UV–Vis absorption spectrum, in which a Voigt profile was fitted. The peak wavelength (λ0), the peak area (A), and the Full Width at Half Maximum (FWHM) were the fitting parameters and were used as the response. The independent factors were the incubation temperature, the incubation time, the silver nitrate, extract, and sodium hydroxide concentrations. The influence of these factors was investigated ‘two factor at a time’, using interaction plots. Strong interaction was observed between all factors, with sodium hydroxide to have a crucial role. The optimum conditions for silver nanoparticle formation were a) OSE (1% v/v), AgNO3 (2 mM), and NaOH (0.2 mM), and b) OMW (2% v/v), AgNO3 (1 mM), and NaOH (7.9 mM), showing an absorption maximum at 414 nm, and 410 nm, respectively. The mean diameter of AgNPs using OMW, measured with Transmission Electron Microscopy was 12.87±4.84 nm. Both types of AgNPs showed antibacterial action against Staphylococcus epidermidis (S. epidermidis) and Escherichia coli (E. coli), using the broth microdilution assay. Both nanoparticle types inhibited bacterial growth up to one dilution higher than reference samples.
{"title":"Green synthesis of silver nanoparticles using olive mill wastewater and olive stones extract and testing their antimicrobial activities against Escherichia coli and Staphylococcus epidermidis","authors":"Nickolas Rigopoulos, Christina Megetho Gkaliouri, Zacharias Ioannou, Efstathios Giaouris, Viktoria Sakavitsi, Dimitrios Gournis","doi":"10.1088/2632-959x/ad2fd1","DOIUrl":"https://doi.org/10.1088/2632-959x/ad2fd1","url":null,"abstract":"Plant mediated synthesis of silver nanoparticles is eco-friendly and of low cost. The synthesis involves a reduction of silver ions and is controlled by several independent factors. In this work, silver nanoparticles (AgNPs) were successfully synthesized using olive stone extract (OSE) and olive mill wastewater (OMW) extract. The nanoparticle synthesis was monitored using the plasmon resonance observed in the UV–Vis absorption spectrum, in which a Voigt profile was fitted. The peak wavelength (<italic toggle=\"yes\">λ</italic>\u0000<sub>0</sub>), the peak area (A), and the Full Width at Half Maximum (FWHM) were the fitting parameters and were used as the response. The independent factors were the incubation temperature, the incubation time, the silver nitrate, extract, and sodium hydroxide concentrations. The influence of these factors was investigated ‘two factor at a time’, using interaction plots. Strong interaction was observed between all factors, with sodium hydroxide to have a crucial role. The optimum conditions for silver nanoparticle formation were a) OSE (1% v/v), AgNO<sub>3</sub> (2 mM), and NaOH (0.2 mM), and b) OMW (2% v/v), AgNO<sub>3</sub> (1 mM), and NaOH (7.9 mM), showing an absorption maximum at 414 nm, and 410 nm, respectively. The mean diameter of AgNPs using OMW, measured with Transmission Electron Microscopy was <inline-formula>\u0000<tex-math>\u0000<?CDATA $12.87pm 4.84$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>12.87</mml:mn><mml:mo>±</mml:mo><mml:mn>4.84</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"nanoxad2fd1ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> nm. Both types of AgNPs showed antibacterial action against <italic toggle=\"yes\">Staphylococcus epidermidis (S. epidermidis)</italic> and <italic toggle=\"yes\">Escherichia coli (E. coli)</italic>, using the broth microdilution assay. Both nanoparticle types inhibited bacterial growth up to one dilution higher than reference samples.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1088/2632-959x/ad2fd3
Aswini Ramakrishnan, Sindhu Swaminathan, Jeyanthinath Mayandi, Deepa K G
This work involves the synthesis of highly conducting, ultra-thin, mesoporous manganese dioxide, nanotubes and nanowires, using a sol–gel technique. This is a template-free method for preparing mesoporous (3.3 to 5.4 nm) nanotubes and nanowires of 10–15 nm radius with surface area (221.19 m2/g-102.09 m2/g). In the MnO2 lattice, oxygen and cationic vacancies are tailored by changing the reducing agent for improved energy storage. X-ray photoelectron spectroscopic studies are conducted to quantify the oxygen and cationic vacancies. The tailored one-dimensional δ-MnO2 is used as an electrode material for symmetric and asymmetric supercapacitor designs. A non-toxic, less volatile aqueous neutral electrolyte is used for the supercapacitive measurement, giving a specific capacitance of 460.75 F g−1 at 2 mV s−1 with symmetric mode at 1 V. With activated carbon, this material can also produce asymmetric supercapacitors with a specific capacitance of 107.38 F g−1 at 10 mV s−1 at 1.7 V.
这项工作涉及利用溶胶-凝胶技术合成高导电性、超薄、介孔二氧化锰、纳米管和纳米线。这是一种无模板方法，用于制备半径为 10-15 nm、表面积为 221.19 m2/g-102.09 m2/g 的介孔（3.3 至 5.4 nm）纳米管和纳米线。在二氧化锰晶格中，通过改变还原剂来定制氧和阳离子空位，从而改善能量存储。通过 X 射线光电子能谱研究对氧和阳离子空位进行了量化。定制的一维 δ-MnO2 可用作对称和非对称超级电容器设计的电极材料。超级电容测量使用的是无毒、挥发性较低的水性中性电解质，在 1 V 的对称模式下，2 mV s-1 的比电容为 460.75 F g-1。利用活性碳，这种材料还能产生不对称超级电容器，在 1.7 V 时，10 mV s-1 的比电容为 107.38 F g-1。
{"title":"Template free synthesis of vacancy tailored, highly mesoporous one-dimensional δ-MnO2 for energy storage applications","authors":"Aswini Ramakrishnan, Sindhu Swaminathan, Jeyanthinath Mayandi, Deepa K G","doi":"10.1088/2632-959x/ad2fd3","DOIUrl":"https://doi.org/10.1088/2632-959x/ad2fd3","url":null,"abstract":"This work involves the synthesis of highly conducting, ultra-thin, mesoporous manganese dioxide, nanotubes and nanowires, using a sol–gel technique. This is a template-free method for preparing mesoporous (3.3 to 5.4 nm) nanotubes and nanowires of 10–15 nm radius with surface area (221.19 m<sup>2</sup>/g-102.09 m<sup>2</sup>/g). In the MnO<sub>2</sub> lattice, oxygen and cationic vacancies are tailored by changing the reducing agent for improved energy storage. X-ray photoelectron spectroscopic studies are conducted to quantify the oxygen and cationic vacancies. The tailored one-dimensional <italic toggle=\"yes\">δ</italic>-MnO<sub>2</sub> is used as an electrode material for symmetric and asymmetric supercapacitor designs. A non-toxic, less volatile aqueous neutral electrolyte is used for the supercapacitive measurement, giving a specific capacitance of 460.75 F g<sup>−1</sup> at 2 mV s<sup>−1</sup> with symmetric mode at 1 V. With activated carbon, this material can also produce asymmetric supercapacitors with a specific capacitance of 107.38 F g<sup>−1</sup> at 10 mV s<sup>−1</sup> at 1.7 V.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1088/2632-959x/ad2fd2
Qihong Lu, Ning Yang, Lei Zuo, Wenjian Fang, Jing Dong, Xianghua Zeng
Zinc cadmium sulfide solid (ZnxCd1−xS) related composites received great attention in photocatalytic hydrogen production because of their tunable bandgap and strong visible light absorption range. But sulfide-based metal materials commonly suffer from photo-corrosion issues. It is very important to construct the photocatalysts with high efficient activity and photostability for H2 production. Herein, we successively prepared ZnCdS/ZnS (ZCS/ZS) heterostructures, ZnCdS/ZnS/MoS2 (ZCS/ZS/M) heterostructures decorated ZCS/ZS with MoS2 quantum dots, then we obtained x-C@ZCS/ZS and x-C@ZCS/ZS/M heterostructures encapsulated ZCS/ZS and ZCS/ZS/M with carbon layer. The performance of the photocatalytic hydrogen production showed that sample 0.05-C@ZCS/ZS/M has a remarkable photocatalytic H2 evolution rate of 15.231 mmol·h−1·g−1 with noble metal-free co-catalysts. This rate was approximately 21 times higher than that of the pristine ZCS/ZS photocatalyst. The optimized sample reveals an excellent stability, without activity losses after 10 h. The improved photocatalytic activity can be attributed to the unique heterojunction structure formed by ZCS/ZS and MoS2. Additionally, the carbon films played a crucial role in providing excellent stability by spatially separating the sites for redox reactions, thereby inhibiting the recombination of photo-generated electron–hole pairs.
{"title":"Photostability and visible-light-driven photoactivity enhancement of hierarchical C@ZnCdS/ZnS/MoS2","authors":"Qihong Lu, Ning Yang, Lei Zuo, Wenjian Fang, Jing Dong, Xianghua Zeng","doi":"10.1088/2632-959x/ad2fd2","DOIUrl":"https://doi.org/10.1088/2632-959x/ad2fd2","url":null,"abstract":"Zinc cadmium sulfide solid (Zn<sub>\u0000<italic toggle=\"yes\">x</italic>\u0000</sub>Cd<sub>1−<italic toggle=\"yes\">x</italic>\u0000</sub>S) related composites received great attention in photocatalytic hydrogen production because of their tunable bandgap and strong visible light absorption range. But sulfide-based metal materials commonly suffer from photo-corrosion issues. It is very important to construct the photocatalysts with high efficient activity and photostability for H<sub>2</sub> production. Herein, we successively prepared ZnCdS/ZnS (ZCS/ZS) heterostructures, ZnCdS/ZnS/MoS<sub>2</sub> (ZCS/ZS/M) heterostructures decorated ZCS/ZS with MoS<sub>2</sub> quantum dots, then we obtained <italic toggle=\"yes\">x</italic>-C@ZCS/ZS and <italic toggle=\"yes\">x</italic>-C@ZCS/ZS/M heterostructures encapsulated ZCS/ZS and ZCS/ZS/M with carbon layer. The performance of the photocatalytic hydrogen production showed that sample 0.05-C@ZCS/ZS/M has a remarkable photocatalytic H<sub>2</sub> evolution rate of 15.231 mmol·h<sup>−1</sup>·g<sup>−1</sup> with noble metal-free co-catalysts. This rate was approximately 21 times higher than that of the pristine ZCS/ZS photocatalyst. The optimized sample reveals an excellent stability, without activity losses after 10 h. The improved photocatalytic activity can be attributed to the unique heterojunction structure formed by ZCS/ZS and MoS<sub>2</sub>. Additionally, the carbon films played a crucial role in providing excellent stability by spatially separating the sites for redox reactions, thereby inhibiting the recombination of photo-generated electron–hole pairs.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1088/2632-959x/ad34a4
Sibel Seven, Evin Yiğit, Sinan Bayındır, Feride Akman, Ö. Sevgili, Osman Dayan, I. Orak
The synthesis and investigation of photoelectric studies of simple organic compounds as organic interlayers are of significant importance and widely studied. As such, we synthesized naphthalene diimide (NDI)-appended ruthenium complexes (Ru-NDIs) to function as the interface layer, and have fabricated novel Al/NDIs or Ru-NDIs/p-Si devices (D1-D4) to investigate their photoelectric properties. Subsequently, we compared and discussed the photoelectric properties of these devices after synthesis and fabrication. According to this, the band-gap energy (Eg) values of organic materials were found to range from 2.95 eV to 3.14 eV, making them ideal for solar cells applications. Additionally, the photoresponse (Pr) values of Al/NDIs or Ru-NDIs/p-Si devices (D1-D4) were found to be 59.25, 1593.08, 198.77, and 134.47, respectively. Moreover, the Al/Ru-NDIs/p-Si D2 structure exhibited the highest Pr values. Experimental results indicate that since the four optoelectronic devices arranged with the derivation of synthesized compounds have good photoresponse characteristics, they can be utilized as a photosensor or photodiodes in different electronic and optoelectronic technologies.
{"title":"The photodiode performances of NDI-appended ruthenium complexes","authors":"Sibel Seven, Evin Yiğit, Sinan Bayındır, Feride Akman, Ö. Sevgili, Osman Dayan, I. Orak","doi":"10.1088/2632-959x/ad34a4","DOIUrl":"https://doi.org/10.1088/2632-959x/ad34a4","url":null,"abstract":"\u0000 The synthesis and investigation of photoelectric studies of simple organic compounds as organic interlayers are of significant importance and widely studied. As such, we synthesized naphthalene diimide (NDI)-appended ruthenium complexes (Ru-NDIs) to function as the interface layer, and have fabricated novel Al/NDIs or Ru-NDIs/p-Si devices (D1-D4) to investigate their photoelectric properties. Subsequently, we compared and discussed the photoelectric properties of these devices after synthesis and fabrication. According to this, the band-gap energy (Eg) values of organic materials were found to range from 2.95 eV to 3.14 eV, making them ideal for solar cells applications. Additionally, the photoresponse (Pr) values of Al/NDIs or Ru-NDIs/p-Si devices (D1-D4) were found to be 59.25, 1593.08, 198.77, and 134.47, respectively. Moreover, the Al/Ru-NDIs/p-Si D2 structure exhibited the highest Pr values. Experimental results indicate that since the four optoelectronic devices arranged with the derivation of synthesized compounds have good photoresponse characteristics, they can be utilized as a photosensor or photodiodes in different electronic and optoelectronic technologies.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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