The major challenge of modern agriculture is to satisfy actual and future global food demands efficiently. This great challenge requires combined efforts to preserve natural resources to support intensive agriculture while limiting detrimental impacts on the environment. One of these efforts is using nanobiotechnology. Nanobiotechnology is the application of nanotechnology in biological science. Nanotechnology is the science of manipulating materials at the nanoscale (1 nm = 10ˉ⁹ m). This review summarizes the potential of nanobiotechnology for its importance in increasing yield in agriculture and providing consumers with quality and contamination-free food. In the agriculture sector, nanobiotechnology is necessarily used as fertilizers (nanofertilizers) for crop yield improvement, pesticides (nanopesticides) for crop protection, and nanobiosensors for the detection of crop pathogens, soil conditions, and vegetation conditions, Similarly, intelligent food packaging, and detection of pathogens, adulterants, and toxins in food are its importance in the food sector.
{"title":"Role of Nanobiotechnology Towards Agri-Food System","authors":"Niguse Hotessa Halake, Jara Muda Haro","doi":"10.1155/2022/6108610","DOIUrl":"https://doi.org/10.1155/2022/6108610","url":null,"abstract":"The major challenge of modern agriculture is to satisfy actual and future global food demands efficiently. This great challenge requires combined efforts to preserve natural resources to support intensive agriculture while limiting detrimental impacts on the environment. One of these efforts is using nanobiotechnology. Nanobiotechnology is the application of nanotechnology in biological science. Nanotechnology is the science of manipulating materials at the nanoscale (1 nm = 10ˉ⁹ m). This review summarizes the potential of nanobiotechnology for its importance in increasing yield in agriculture and providing consumers with quality and contamination-free food. In the agriculture sector, nanobiotechnology is necessarily used as fertilizers (nanofertilizers) for crop yield improvement, pesticides (nanopesticides) for crop protection, and nanobiosensors for the detection of crop pathogens, soil conditions, and vegetation conditions, Similarly, intelligent food packaging, and detection of pathogens, adulterants, and toxins in food are its importance in the food sector.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83280301","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}
The deterioration of the quality of groundwater by fluoride is the cause of shortage of drinking water supply in the rift valley region. Most people living in the rural areas are using groundwater as the source of their potable water; however, it is contaminated with high concentrations of fluoride ion above the permissible level. Hence, this study was designed to investigate the adsorption of fluoride from groundwater by graphene oxide (GO) under specific conditions, such as: agitation rate of 120 rpm, contact time of 90 minutes, adsorbent dosage of 0.42 mg/L, initial fluoride concentration of 10 mg/L, and pH of 6.8. The result obtained showed 99.3% fluoride removal from the NaF prepared solution and 91.6% fluoride removal from the real sample. The retained properties of GO after adsorption observed on UV–Vis analysis confirmed that the adsorbent can be recyclable. The result obtained also showed that the adsorption kinetics with the coefficient of determination (R2) for pseudo-second order (SSO) and pseudo-first order (SFO) were 0.99 and 0.96, respectively. Based on these results, the adsorption of fluoride onto GO is a pseudo-second-order kinetics type. According to the result, the Freundlich isotherm model showed a good fit to the experiment with R2 (0.99). The adsorption capacity of the adsorbent was found to be 301.43 mg/g. Hence, this study showed that GO is the preferred adsorbent for the removal of fluoride from groundwater.
{"title":"Graphene Oxide Nanoadsorbent for the Removal of Fluoride Ion from Groundwater: Adsorbent Performance and Adsorption Mechanism","authors":"Bayisa Meka Chufa, B. Gonfa, T. Y. Anshebo","doi":"10.1155/2022/7371227","DOIUrl":"https://doi.org/10.1155/2022/7371227","url":null,"abstract":"The deterioration of the quality of groundwater by fluoride is the cause of shortage of drinking water supply in the rift valley region. Most people living in the rural areas are using groundwater as the source of their potable water; however, it is contaminated with high concentrations of fluoride ion above the permissible level. Hence, this study was designed to investigate the adsorption of fluoride from groundwater by graphene oxide (GO) under specific conditions, such as: agitation rate of 120 rpm, contact time of 90 minutes, adsorbent dosage of 0.42 mg/L, initial fluoride concentration of 10 mg/L, and pH of 6.8. The result obtained showed 99.3% fluoride removal from the NaF prepared solution and 91.6% fluoride removal from the real sample. The retained properties of GO after adsorption observed on UV–Vis analysis confirmed that the adsorbent can be recyclable. The result obtained also showed that the adsorption kinetics with the coefficient of determination (R2) for pseudo-second order (SSO) and pseudo-first order (SFO) were 0.99 and 0.96, respectively. Based on these results, the adsorption of fluoride onto GO is a pseudo-second-order kinetics type. According to the result, the Freundlich isotherm model showed a good fit to the experiment with R2 (0.99). The adsorption capacity of the adsorbent was found to be 301.43 mg/g. Hence, this study showed that GO is the preferred adsorbent for the removal of fluoride from groundwater.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84997543","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}
In this study, zinc oxide-activated carbon nanocomposite was used as the adsorbent for the remediation of dieldrin in aqueous media. Zinc oxide nanoparticles (ZNPs) were synthesized from Cissus quadrangularis (C. quadrangularis) leaf extract, and activated carbon was derived from maize cobs. Nanocomposites were formulated by mixing the ZNPs with the activated carbon in a ratio of 1 : 50. The UV-Vis spectra showed a complete reduction of Zn2+ to Zn0 with plasmon resonance bands in the range of 361–376 nm, which is a characteristic of ZNPs. The SEM images of ZNPs showed hexagonal-shaped particles of 15–20 nm, with face-centered cubic crystals, as demonstrated by XRD analysis. FTIR results showed absorption bands in the ranges 3500–3100 cm−1 (N-H stretch), 3400–2400 cm−1 (O-H stretch), 988–830 cm−1 (C-H bend), 1612 cm−1 (C=C stretch), 400–600 cm−1 (Zn-O stretch), and 1271 cm−1 (C-O bend). Batch adsorption experiments were performed using 20 ml of dieldrin solution at varying pH values (1–14), concentrations (5–100 ppm), temperatures (293–323 K), adsorbent dosages (0.01–0.12 g), and contact times (30–180 minutes) to determine the optimum conditions. The calculated thermodynamic parameters (ΔH°, ΔS°, and ΔG°) indicated that the adsorption was spontaneous and exothermic in nature, implying decreasing randomness of dieldrin molecules at the solid-liquid interface. The isotherm and adsorption kinetics for the composite showed that the absorption process followed Langmuir isotherm and pseudo-second-order kinetics. Adsorption capacities of the nanoparticles, activated carbon, and nanocomposite at a reaction time of 120 minutes and pH of 7 were 3.72 ± 0.068 mg/g, 3.92 ± 0.061 mg/g, and 4.0 ± 0.102 mg/g, respectively, with corresponding percentage removals of 93.12 ± 0.044, 98.04 ± 0.044, and 99.76 ± 0.332. Thus, the nanocomposite exhibited a better sorbing potential for dieldrin in solution than activated carbon. This study recommends testing the remediation potential of the synthesized nanocomposite on other persistent organic pollutants.
{"title":"Synthesis, Characterization, and Evaluation of the Remediation Activity of Cissus quadrangularis Zinc Oxide Nanoparticle-Activated Carbon Composite on Dieldrin in Aqueous Solution","authors":"Calvince Ondijo, F. Kengara, Isaac O. K’Owino","doi":"10.1155/2022/2055024","DOIUrl":"https://doi.org/10.1155/2022/2055024","url":null,"abstract":"In this study, zinc oxide-activated carbon nanocomposite was used as the adsorbent for the remediation of dieldrin in aqueous media. Zinc oxide nanoparticles (ZNPs) were synthesized from Cissus quadrangularis (C. quadrangularis) leaf extract, and activated carbon was derived from maize cobs. Nanocomposites were formulated by mixing the ZNPs with the activated carbon in a ratio of 1 : 50. The UV-Vis spectra showed a complete reduction of Zn2+ to Zn0 with plasmon resonance bands in the range of 361–376 nm, which is a characteristic of ZNPs. The SEM images of ZNPs showed hexagonal-shaped particles of 15–20 nm, with face-centered cubic crystals, as demonstrated by XRD analysis. FTIR results showed absorption bands in the ranges 3500–3100 cm−1 (N-H stretch), 3400–2400 cm−1 (O-H stretch), 988–830 cm−1 (C-H bend), 1612 cm−1 (C=C stretch), 400–600 cm−1 (Zn-O stretch), and 1271 cm−1 (C-O bend). Batch adsorption experiments were performed using 20 ml of dieldrin solution at varying pH values (1–14), concentrations (5–100 ppm), temperatures (293–323 K), adsorbent dosages (0.01–0.12 g), and contact times (30–180 minutes) to determine the optimum conditions. The calculated thermodynamic parameters (ΔH°, ΔS°, and ΔG°) indicated that the adsorption was spontaneous and exothermic in nature, implying decreasing randomness of dieldrin molecules at the solid-liquid interface. The isotherm and adsorption kinetics for the composite showed that the absorption process followed Langmuir isotherm and pseudo-second-order kinetics. Adsorption capacities of the nanoparticles, activated carbon, and nanocomposite at a reaction time of 120 minutes and pH of 7 were 3.72 ± 0.068 mg/g, 3.92 ± 0.061 mg/g, and 4.0 ± 0.102 mg/g, respectively, with corresponding percentage removals of 93.12 ± 0.044, 98.04 ± 0.044, and 99.76 ± 0.332. Thus, the nanocomposite exhibited a better sorbing potential for dieldrin in solution than activated carbon. This study recommends testing the remediation potential of the synthesized nanocomposite on other persistent organic pollutants.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90917670","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}
We have studied the 1.55 μm optical properties of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs quantum wells using a self-consistent calculation combined with the anticrossing model. We have found that the increase of injected carriers’ density induces the increase of optical gain and radiative current density. The rise of doping density causes a blue shift of the fundamental transition energy accompanied with significant increase of optical gain. The quantum-confined Stark effect on radiative current density is also studied. The variation of radiative current as function of well width and Sb composition is also examined. In order to operate the emission wavelength at the optical fiber telecommunication domain, we have adjusted the well parameters of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs.
{"title":"Optical Investigation of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs Quantum Wells Emitters","authors":"I. Guizani, C. Bilel, Malak Alrowaili, A. Rebey","doi":"10.1155/2022/7971119","DOIUrl":"https://doi.org/10.1155/2022/7971119","url":null,"abstract":"We have studied the 1.55 μm optical properties of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs quantum wells using a self-consistent calculation combined with the anticrossing model. We have found that the increase of injected carriers’ density induces the increase of optical gain and radiative current density. The rise of doping density causes a blue shift of the fundamental transition energy accompanied with significant increase of optical gain. The quantum-confined Stark effect on radiative current density is also studied. The variation of radiative current as function of well width and Sb composition is also examined. In order to operate the emission wavelength at the optical fiber telecommunication domain, we have adjusted the well parameters of p-GaAs/i-GaN0.38yAs1-1.38ySby/n-GaAs.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72827626","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}
M. Mostafa, Z. Alrowaili, M.M. Al Shehri, M. Mobarak, A. Abbas
Ceramic materials have been used in various human health-related applications for considerable time. One of the important applications of ceramic materials is in electronics. Our work focuses on calcium titanate (CaTiO3). CaTiO3 is typically created via sintering. Gypsum particles is used to form calcium hydroxide, which is then combined with titanium dioxide to form rutile crystals. Thereafter, calcination is performed at 900°C, 1000°C, and 1100°C for 2 h. X-ray diffraction is employed to track the evolution of the CaTiO3 phase. Scanning electron microscopy is used to characterize the morphologies of the different preparation steps. As the calcination temperature increases from 900°C to 1000°C, the crystallite size of CaTiO3 increases from 35 nm to 45 nm. Furthermore, the energy gaps of the CaTiO3 powders obtained after calcination at 900°C and 1000°C are 5.32 eV and 5.43 eV, respectively, and their particle sizes are 150–200 nm and 200–300 nm, respectively.
{"title":"Structural and Optical Properties of Calcium Titanate Prepared from Gypsum","authors":"M. Mostafa, Z. Alrowaili, M.M. Al Shehri, M. Mobarak, A. Abbas","doi":"10.1155/2022/6020378","DOIUrl":"https://doi.org/10.1155/2022/6020378","url":null,"abstract":"Ceramic materials have been used in various human health-related applications for considerable time. One of the important applications of ceramic materials is in electronics. Our work focuses on calcium titanate (CaTiO3). CaTiO3 is typically created via sintering. Gypsum particles is used to form calcium hydroxide, which is then combined with titanium dioxide to form rutile crystals. Thereafter, calcination is performed at 900°C, 1000°C, and 1100°C for 2 h. X-ray diffraction is employed to track the evolution of the CaTiO3 phase. Scanning electron microscopy is used to characterize the morphologies of the different preparation steps. As the calcination temperature increases from 900°C to 1000°C, the crystallite size of CaTiO3 increases from 35 nm to 45 nm. Furthermore, the energy gaps of the CaTiO3 powders obtained after calcination at 900°C and 1000°C are 5.32 eV and 5.43 eV, respectively, and their particle sizes are 150–200 nm and 200–300 nm, respectively.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75444817","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}
Darbin Kumar Poudel, Purushottam Niraula, Himal Aryal, Biplab Budhathoki, S. Phuyal, R. Marahatha, Kiran Subedi
The potential applications of Ag NPs are exciting and beneficial in a variety of fields; however, there is less awareness of the new risks posed by inappropriate disposal of Ag NPs. The Ag NPs have medicinal, plasmonic, and catalytic properties. The Ag NPs can be prepared via physical, chemical, or biological routes, and the selection of any specific route depends largely on the end-use. The downside of a physical and chemical approach is that it requires a wide space, high temperature, high temperature for a longer time to preserve the thermal stability of synthesized Ag NPs, and the use of toxic chemicals. Although these methods produce nanoparticles with high purity and well-defined morphology, it is critical to develop cost-effective, energy-efficient, and facile route, such as green synthesis; it suggests the desirable use of renewable resources by avoiding the use of additional solvents and toxic reagents in order to achieve the ultimate goal. However, each method has its pros and cons. The synthesized Ag NPs obtained using the green approach have larger biocompatibility and are less toxic towards the biotic systems. However, identifying the phytoconstituents that are responsible for nanoparticle synthesis is difficult and has been reported as a suitable candidate for biological application. The concentration of the effective bioreducing phytoconstituents plays a crucial role in deciding the morphology of the nanoparticle. Besides these reaction times, temperature, pH, and concentration of silver salt are some of the key factors that determine the morphology. Hence, careful optimization in the methodology is required as different morphologies have different properties and usage. It is due to which the development of methods to prepare nanoparticles effectively using various plant extracts is gaining rapid momentum in recent days. To make sense of what involves in the bioreduction of silver salt and to isolate the secondary metabolites from plants are yet challenging. This review focuses on the contribution of plant-mediated Ag NPs in different applications and their toxicity in the aquatic system.
{"title":"Plant-Mediated Green Synthesis of Ag NPs and Their Possible Applications: A Critical Review","authors":"Darbin Kumar Poudel, Purushottam Niraula, Himal Aryal, Biplab Budhathoki, S. Phuyal, R. Marahatha, Kiran Subedi","doi":"10.1155/2022/2779237","DOIUrl":"https://doi.org/10.1155/2022/2779237","url":null,"abstract":"The potential applications of Ag NPs are exciting and beneficial in a variety of fields; however, there is less awareness of the new risks posed by inappropriate disposal of Ag NPs. The Ag NPs have medicinal, plasmonic, and catalytic properties. The Ag NPs can be prepared via physical, chemical, or biological routes, and the selection of any specific route depends largely on the end-use. The downside of a physical and chemical approach is that it requires a wide space, high temperature, high temperature for a longer time to preserve the thermal stability of synthesized Ag NPs, and the use of toxic chemicals. Although these methods produce nanoparticles with high purity and well-defined morphology, it is critical to develop cost-effective, energy-efficient, and facile route, such as green synthesis; it suggests the desirable use of renewable resources by avoiding the use of additional solvents and toxic reagents in order to achieve the ultimate goal. However, each method has its pros and cons. The synthesized Ag NPs obtained using the green approach have larger biocompatibility and are less toxic towards the biotic systems. However, identifying the phytoconstituents that are responsible for nanoparticle synthesis is difficult and has been reported as a suitable candidate for biological application. The concentration of the effective bioreducing phytoconstituents plays a crucial role in deciding the morphology of the nanoparticle. Besides these reaction times, temperature, pH, and concentration of silver salt are some of the key factors that determine the morphology. Hence, careful optimization in the methodology is required as different morphologies have different properties and usage. It is due to which the development of methods to prepare nanoparticles effectively using various plant extracts is gaining rapid momentum in recent days. To make sense of what involves in the bioreduction of silver salt and to isolate the secondary metabolites from plants are yet challenging. This review focuses on the contribution of plant-mediated Ag NPs in different applications and their toxicity in the aquatic system.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75577602","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}
Iron oxide nanoparticles (α- Fe2O3) were synthesized using an unconventional, eco-friendly technique utilizing a Hibiscus rosa sinensis flower (common name, China rose) extract as a reducer and stabilizer agent. The microwave method was successfully used for the synthesis of iron oxide nanoparticles. Various volume ratios of iron chloride tetrahydrate to the extract were taken and heated by the microwave oven for different periods to optimize iron oxide nanoparticle production. The synthesized iron oxide nanoparticles were characterized using the ultraviolet-visible spectrometer (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). X-ray diffraction confirmed the formation of α- Fe2O3 nanoparticles (hematite). The average size of iron oxide nanoparticles was found to be 51 nm. The antibacterial activity of the synthesized iron nanoparticles was investigated against different bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli. The results showed that the synthesized iron nanoparticles exhibited an inhabitation effect on all studied bacteria.
{"title":"Green Synthesis of Iron Oxide Nanoparticles Using Hibiscus rosa sinensis Flowers and Their Antibacterial Activity","authors":"F. Buarki, H. AbuHassan, F. Al Hannan, F. Henari","doi":"10.1155/2022/5474645","DOIUrl":"https://doi.org/10.1155/2022/5474645","url":null,"abstract":"Iron oxide nanoparticles (α- Fe2O3) were synthesized using an unconventional, eco-friendly technique utilizing a Hibiscus rosa sinensis flower (common name, China rose) extract as a reducer and stabilizer agent. The microwave method was successfully used for the synthesis of iron oxide nanoparticles. Various volume ratios of iron chloride tetrahydrate to the extract were taken and heated by the microwave oven for different periods to optimize iron oxide nanoparticle production. The synthesized iron oxide nanoparticles were characterized using the ultraviolet-visible spectrometer (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). X-ray diffraction confirmed the formation of α- Fe2O3 nanoparticles (hematite). The average size of iron oxide nanoparticles was found to be 51 nm. The antibacterial activity of the synthesized iron nanoparticles was investigated against different bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli. The results showed that the synthesized iron nanoparticles exhibited an inhabitation effect on all studied bacteria.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83849460","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}
A. Kotbi, M. Imran, K. Kaja, A. Rahaman, El Mostafa Ressami, M. Lejeune, B. Lakssir, M. Jouiad
The efficient monitoring of the environment is currently gaining a continuous growing interest in view of finding solutions for the global pollution issues and their associated climate change. In this sense, two-dimensional (2D) materials appear as one of highly attractive routes for the development of efficient sensing devices due, in particular, to the interesting blend of their superlative properties. For instance, graphene (Gr) and graphitic carbon nitride g-C3N4 (g-CN) have specifically attracted great attention in several domains of sensing applications owing to their excellent electronic and physical-chemical properties. Despite the high potential they offer in the development and fabrication of high-performance gas-sensing devices, an exhaustive comparison between Gr and g-CN is not well established yet regarding their electronic properties and their sensing performances such as sensitivity and selectivity. Hence, this work aims at providing a state-of-the-art overview of the latest experimental advances in the fabrication, characterization, development, and implementation of these 2D materials in gas-sensing applications. Then, the reported results are compared to our numerical simulations using density functional theory carried out on the interactions of Gr and g-CN with some selected hazardous gases’ molecules such as NO2, CO2, and HF. Our findings conform with the superior performances of the g-CN regarding HF detection, while both g-CN and Gr show comparable detection performances for the remaining considered gases. This allows suggesting an outlook regarding the future use of these 2D materials as high-performance gas sensors.
{"title":"Graphene and g-C3N4-Based Gas Sensors","authors":"A. Kotbi, M. Imran, K. Kaja, A. Rahaman, El Mostafa Ressami, M. Lejeune, B. Lakssir, M. Jouiad","doi":"10.1155/2022/9671619","DOIUrl":"https://doi.org/10.1155/2022/9671619","url":null,"abstract":"The efficient monitoring of the environment is currently gaining a continuous growing interest in view of finding solutions for the global pollution issues and their associated climate change. In this sense, two-dimensional (2D) materials appear as one of highly attractive routes for the development of efficient sensing devices due, in particular, to the interesting blend of their superlative properties. For instance, graphene (Gr) and graphitic carbon nitride g-C3N4 (g-CN) have specifically attracted great attention in several domains of sensing applications owing to their excellent electronic and physical-chemical properties. Despite the high potential they offer in the development and fabrication of high-performance gas-sensing devices, an exhaustive comparison between Gr and g-CN is not well established yet regarding their electronic properties and their sensing performances such as sensitivity and selectivity. Hence, this work aims at providing a state-of-the-art overview of the latest experimental advances in the fabrication, characterization, development, and implementation of these 2D materials in gas-sensing applications. Then, the reported results are compared to our numerical simulations using density functional theory carried out on the interactions of Gr and g-CN with some selected hazardous gases’ molecules such as NO2, CO2, and HF. Our findings conform with the superior performances of the g-CN regarding HF detection, while both g-CN and Gr show comparable detection performances for the remaining considered gases. This allows suggesting an outlook regarding the future use of these 2D materials as high-performance gas sensors.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85145754","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}
In the study, chitosan was decomposed into low molecular weight chitosan by using different H2O2 concentrations for chain termination, and then chitosan was prepared with different concentrations of tripolyphosphate cations (TPP). We have obtained the following result: the formation of chitosan depends on the concentration of TPP; TPP at low or high concentrations does not react with chitosan to form small chitosan molecules. Properly structured chitosan is only obtained when the mass ratio of chitosan/TPP is 6 : 3. At this rate, when the mass ratio of chitosan/TPP is approximately 6 : 3, there the formed nanochitosan particles have good antibacterial ability against strains of E. coli, M. catarrhalis, and S. aureus. In this work, initially, a successful preparation of a suspension between nasal spray and small chitosan suspension was found at manufacturing ratios: 5 ml nasal spray and 5 ml manufactured chitosan suspension at concentrations of 1 mg/ml, 3 mg/ml, and 5 mg/ml. It proves that the chain termination process by using H2O2 and the creation cross-linking when adding TPP are successful to a certain extent.
{"title":"Study on Fabrication of Antibacterial Low Molecular Weight Nanochitosan Using Sodium Tripolyphosphate and Hydrogen Peroxide","authors":"T. Nguyen, T. Nguyen","doi":"10.1155/2022/8368431","DOIUrl":"https://doi.org/10.1155/2022/8368431","url":null,"abstract":"In the study, chitosan was decomposed into low molecular weight chitosan by using different H2O2 concentrations for chain termination, and then chitosan was prepared with different concentrations of tripolyphosphate cations (TPP). We have obtained the following result: the formation of chitosan depends on the concentration of TPP; TPP at low or high concentrations does not react with chitosan to form small chitosan molecules. Properly structured chitosan is only obtained when the mass ratio of chitosan/TPP is 6 : 3. At this rate, when the mass ratio of chitosan/TPP is approximately 6 : 3, there the formed nanochitosan particles have good antibacterial ability against strains of E. coli, M. catarrhalis, and S. aureus. In this work, initially, a successful preparation of a suspension between nasal spray and small chitosan suspension was found at manufacturing ratios: 5 ml nasal spray and 5 ml manufactured chitosan suspension at concentrations of 1 mg/ml, 3 mg/ml, and 5 mg/ml. It proves that the chain termination process by using H2O2 and the creation cross-linking when adding TPP are successful to a certain extent.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78025242","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}
Background. With the recent increase in antibiotic resistance to conventional antibiotics, gold nanoparticles, and medicinal plants, extracts present an interesting alternative. Objectives. This study aimed to synthesize, characterize, and evaluate Pyrenacantha grandiflora Baill extracts and gold nanoparticle conjugates against pathogenic bacteria. Methods. We synthesized gold nanoparticles by chemical and biological methods. The nanoparticles were characterized by the use of UV-visible spectrophotometry, followed by transmission electron microscopy (TEM) and energy-dispersive X-ray analysis (EDX). Gold nanoparticles were conjugated to plant extracts and analyzed with a Fourier-transform infrared spectroscope (FTIR). We determined the antimicrobial activity of the conjugates using well diffusion and the microdilution assays. Results. The UV–visible spectra of gold nanoparticles showed a synthesis peak at 530 nm. FTIR analysis indicated functional biomolecules that were associated with plant extract conjugated gold nanoparticles; the formation of C–H group and carbonyl (C=O) groups, –OH carbonyl, and C≡C groups were also observed. Biologically synthesized nanoparticles were star-shaped when observed by TEM with an average size of 11 nm. Gold nanoparticles synthesized with P. grandiflora water extracts showed the largest zone of inhibition (22 mm). When the gold nanoparticles synthesized by the biological method were conjugated with acetone extracts of P. grandiflora, MIC as low as 0.0063 mg/mL was observed against beta-lactamase producing K. pneumonia. The activity of acetone extracts was improved with chemically synthesized gold nanoparticles particularly when beta-lactamase producing E. coli and MRSA were used as test organisms. A synergistic effect was observed against all tested bacteria, except for MRSA when gold nanoparticles were conjugated with acetone extract. Conclusion. Overall, P. grandiflora tuber extracts conjugated with gold nanoparticles showed a very good antibacterial activity that improved both plant extract and gold nanoparticle’s individual activity.
{"title":"Syntheses, Characterization, and Antibacterial Evaluation of P. grandiflora Extracts Conjugated with Gold Nanoparticles","authors":"A. Murei, K. Pillay, A. Samie","doi":"10.1155/2021/8687627","DOIUrl":"https://doi.org/10.1155/2021/8687627","url":null,"abstract":"Background. With the recent increase in antibiotic resistance to conventional antibiotics, gold nanoparticles, and medicinal plants, extracts present an interesting alternative. Objectives. This study aimed to synthesize, characterize, and evaluate Pyrenacantha grandiflora Baill extracts and gold nanoparticle conjugates against pathogenic bacteria. Methods. We synthesized gold nanoparticles by chemical and biological methods. The nanoparticles were characterized by the use of UV-visible spectrophotometry, followed by transmission electron microscopy (TEM) and energy-dispersive X-ray analysis (EDX). Gold nanoparticles were conjugated to plant extracts and analyzed with a Fourier-transform infrared spectroscope (FTIR). We determined the antimicrobial activity of the conjugates using well diffusion and the microdilution assays. Results. The UV–visible spectra of gold nanoparticles showed a synthesis peak at 530 nm. FTIR analysis indicated functional biomolecules that were associated with plant extract conjugated gold nanoparticles; the formation of C–H group and carbonyl (C=O) groups, –OH carbonyl, and C≡C groups were also observed. Biologically synthesized nanoparticles were star-shaped when observed by TEM with an average size of 11 nm. Gold nanoparticles synthesized with P. grandiflora water extracts showed the largest zone of inhibition (22 mm). When the gold nanoparticles synthesized by the biological method were conjugated with acetone extracts of P. grandiflora, MIC as low as 0.0063 mg/mL was observed against beta-lactamase producing K. pneumonia. The activity of acetone extracts was improved with chemically synthesized gold nanoparticles particularly when beta-lactamase producing E. coli and MRSA were used as test organisms. A synergistic effect was observed against all tested bacteria, except for MRSA when gold nanoparticles were conjugated with acetone extract. Conclusion. Overall, P. grandiflora tuber extracts conjugated with gold nanoparticles showed a very good antibacterial activity that improved both plant extract and gold nanoparticle’s individual activity.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2021-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81421974","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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