J. Echave, C. Lourenço-Lopes, A. Carreira-Casais, F. Chamorro, M. Fraga-Corral, P. Otero, P. García-Pérez, Sergio Baamonde, Fermín Fernández-Saa, H. Cao, Jianbo Xiao, M. Prieto, J. Simal-Gándara
Macroalgae are regarded as a healthy food due to their composition and nutritional properties. In this work, nutritional composition of two green (Ulva rigida, Codium tomentosum) and two red (Palmaria palmata, Porphyra purpurea) edible seaweed was studied. Total lipids were measured gravimetrically as evaporated mass after petroleum-ether Soxhlet extraction of samples. In addition, fatty acid profile was determined by gas chromatography coupled to a flame ionization detector (GC-FID). Results showed that all studied species were accounted for very low levels of lipids (<1% dw), but levels of unsaturated fatty acids oleic, linoleic, and linolenic acids were present at high concentrations, with P. palmata displaying the highest quantities (>200 mg C18:1/g extract). In parallel, proteins were quantified following the macro-Kjeldahl method. In this analysis, red algae, especially P. purpurea, showed significant protein content up to 30% DW. Total organic acids were found by ultra-filtration liquid-chromatography coupled to an amperometry detector (UFLC-PAD) after an acid extraction, P. purpurea being the algae with the higher organic acid content (10.61% dw). Minerals were identified and quantified by inductively coupled plasma atomic emission spectroscopy (ICP-OES), suggesting that both algae groups are rich in K and Mg (>15 g/kg), but U. rigida also displayed a remarkable iron content (>1 g Fe/kg). Other detected minerals in minor concentrations were Ca, P or F. Altogether, results corroborate that these edible algae are a good source of nutrients in accordance with literature.
{"title":"Nutritional Composition of the Atlantic Seaweeds Ulva rigida, Codium tomentosum, Palmaria palmata and Porphyra purpurea","authors":"J. Echave, C. Lourenço-Lopes, A. Carreira-Casais, F. Chamorro, M. Fraga-Corral, P. Otero, P. García-Pérez, Sergio Baamonde, Fermín Fernández-Saa, H. Cao, Jianbo Xiao, M. Prieto, J. Simal-Gándara","doi":"10.3390/csac2021-10681","DOIUrl":"https://doi.org/10.3390/csac2021-10681","url":null,"abstract":"Macroalgae are regarded as a healthy food due to their composition and nutritional properties. In this work, nutritional composition of two green (Ulva rigida, Codium tomentosum) and two red (Palmaria palmata, Porphyra purpurea) edible seaweed was studied. Total lipids were measured gravimetrically as evaporated mass after petroleum-ether Soxhlet extraction of samples. In addition, fatty acid profile was determined by gas chromatography coupled to a flame ionization detector (GC-FID). Results showed that all studied species were accounted for very low levels of lipids (<1% dw), but levels of unsaturated fatty acids oleic, linoleic, and linolenic acids were present at high concentrations, with P. palmata displaying the highest quantities (>200 mg C18:1/g extract). In parallel, proteins were quantified following the macro-Kjeldahl method. In this analysis, red algae, especially P. purpurea, showed significant protein content up to 30% DW. Total organic acids were found by ultra-filtration liquid-chromatography coupled to an amperometry detector (UFLC-PAD) after an acid extraction, P. purpurea being the algae with the higher organic acid content (10.61% dw). Minerals were identified and quantified by inductively coupled plasma atomic emission spectroscopy (ICP-OES), suggesting that both algae groups are rich in K and Mg (>15 g/kg), but U. rigida also displayed a remarkable iron content (>1 g Fe/kg). Other detected minerals in minor concentrations were Ca, P or F. Altogether, results corroborate that these edible algae are a good source of nutrients in accordance with literature.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77088892","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 environmental, industrial, and biomedical fields, pH monitorization is of the upmost importance. However, the most used type of pH sensors, glass pH-electrodes, still present limitations in their application in low volume samples and in cellular pH sensing, due to their size and invasive nature. Fluorescence-based sensors present a solution to such issues, providing a non-invasive solution to pH sensing. Herein, we report the rational development of carbon dots (CDs) as a pH nanosensor via an active surface preservation (ASP) method. Carbon dots (CDs) are carbon-based fluorescent nanoparticles with valuable properties such as high aqueous solubility, low cost and good biocompatibility, with remarkable fluorescence performance, been increasingly used as fluorescent nanosensors. Namely, these nanomaterials present advantages over molecular probes in terms of (photo)stability and water solubility, among others. By employing ASP strategies, the CDs will be prepared by using precursors with known active functional features. The ASP method allows the nanoparticles to retain the structural features of precursors, thus retaining their properties, without the need for costly and time-consuming post-synthesis functionalization procedures. In this work, we intend to provide a proof-of-concept of this type of strategy by utilizing the known pH-sensitivity of fluorescein to provide a pH-based response to CDs. The resulting CDs presented reversible response by fluorescence enhancement in the range of pH from 4 to 12. The nanoparticles exhibited excellent photostability, in different pH solutions. The studied CDs were also unaffected by, either variation of ionic strength or the presence of interferent species, while being compatible with human cancer cells. Finally, CDs were able to determine the pH of real samples. Thus, a selective pH fluorescent CDs-based nanosensor was developed.
{"title":"Carbon Dots as a Fluorescence pH Nanosensor by Application of an Active Surface Preservation Strategy","authors":"A. C. P. Afonso, Luís Pinto da Silva","doi":"10.3390/csac2021-10638","DOIUrl":"https://doi.org/10.3390/csac2021-10638","url":null,"abstract":"In the environmental, industrial, and biomedical fields, pH monitorization is of the upmost importance. However, the most used type of pH sensors, glass pH-electrodes, still present limitations in their application in low volume samples and in cellular pH sensing, due to their size and invasive nature. Fluorescence-based sensors present a solution to such issues, providing a non-invasive solution to pH sensing. Herein, we report the rational development of carbon dots (CDs) as a pH nanosensor via an active surface preservation (ASP) method. Carbon dots (CDs) are carbon-based fluorescent nanoparticles with valuable properties such as high aqueous solubility, low cost and good biocompatibility, with remarkable fluorescence performance, been increasingly used as fluorescent nanosensors. Namely, these nanomaterials present advantages over molecular probes in terms of (photo)stability and water solubility, among others. By employing ASP strategies, the CDs will be prepared by using precursors with known active functional features. The ASP method allows the nanoparticles to retain the structural features of precursors, thus retaining their properties, without the need for costly and time-consuming post-synthesis functionalization procedures. In this work, we intend to provide a proof-of-concept of this type of strategy by utilizing the known pH-sensitivity of fluorescein to provide a pH-based response to CDs. The resulting CDs presented reversible response by fluorescence enhancement in the range of pH from 4 to 12. The nanoparticles exhibited excellent photostability, in different pH solutions. The studied CDs were also unaffected by, either variation of ionic strength or the presence of interferent species, while being compatible with human cancer cells. Finally, CDs were able to determine the pH of real samples. Thus, a selective pH fluorescent CDs-based nanosensor was developed.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75190286","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}
G. Buica, Georgiana-Luiza Tatu (Arnold), E. Ungureanu, G. Vasile
In recent years, many applications have been developed for the detection of different toxic metals (As, Cd, Cu, Hg, Ni, Pb) in water samples. The classic analytical methods (ICP-MS, AAS with graphite furnace, ICP-EOS with ultrasonic nebulizer) not only require a longer analysis time (pretreatment of the sample and analysis), but also the costs involved are higher as a result of expensive equipment, costs associated with the method validation process and qualified staff. The use of modified electrodes for trace metals analysi from wastewater samples represents a modern approach which can provide accurate, fast results with selectivity and sensitivity. Thus, here we present the development of the previously obtained glassy carbon-modified electrodes based on poly(2,2′-(ethane-1,2-diylbis((2-(azulen-2-ylamino)-2-oxoethyl)azanediyl))diacetic acid, (polyL) in laboratory-scale studies. In order to analyze Hg(II) ion content from aqueous samples, an assembly system made of carbon screen-printed modified electrodes (SPEs) modified with polyL selective complexing polymeric films coupled with a portable potentiostat was used. The detection of Hg(II) ions was accomplished by chemical accumulation in an open circuit followed by anodic stripping using the differential pulse voltammetry technique. The calibration curve of the analytical method was situated in the range of 20 ppb to 150 ppb (y = 0.0051x + 0.123, R2 = 0.9951), with a detection limit of 6 ppb. The precision value for the lower limit of the calibration curve was 20%, while for the upper limit, the value was 10.5%. The novelty of the method consists not only of the low cost of the analysis, but also of the possibility to provide real-time reliable information about the Hg(II) concentration in wastewater using a small and portable device.
{"title":"Voltammetric Detection of Mercury Ions at Poly(azulene-EDTA)-like Screen Printed Modified Electrodes","authors":"G. Buica, Georgiana-Luiza Tatu (Arnold), E. Ungureanu, G. Vasile","doi":"10.3390/csac2021-10630","DOIUrl":"https://doi.org/10.3390/csac2021-10630","url":null,"abstract":"In recent years, many applications have been developed for the detection of different toxic metals (As, Cd, Cu, Hg, Ni, Pb) in water samples. The classic analytical methods (ICP-MS, AAS with graphite furnace, ICP-EOS with ultrasonic nebulizer) not only require a longer analysis time (pretreatment of the sample and analysis), but also the costs involved are higher as a result of expensive equipment, costs associated with the method validation process and qualified staff. The use of modified electrodes for trace metals analysi from wastewater samples represents a modern approach which can provide accurate, fast results with selectivity and sensitivity. Thus, here we present the development of the previously obtained glassy carbon-modified electrodes based on poly(2,2′-(ethane-1,2-diylbis((2-(azulen-2-ylamino)-2-oxoethyl)azanediyl))diacetic acid, (polyL) in laboratory-scale studies. In order to analyze Hg(II) ion content from aqueous samples, an assembly system made of carbon screen-printed modified electrodes (SPEs) modified with polyL selective complexing polymeric films coupled with a portable potentiostat was used. The detection of Hg(II) ions was accomplished by chemical accumulation in an open circuit followed by anodic stripping using the differential pulse voltammetry technique. The calibration curve of the analytical method was situated in the range of 20 ppb to 150 ppb (y = 0.0051x + 0.123, R2 = 0.9951), with a detection limit of 6 ppb. The precision value for the lower limit of the calibration curve was 20%, while for the upper limit, the value was 10.5%. The novelty of the method consists not only of the low cost of the analysis, but also of the possibility to provide real-time reliable information about the Hg(II) concentration in wastewater using a small and portable device.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73965305","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 studied the preparation and gas-sensing performance of a hybrid nanomaterial based on titania nanotubes and graphene derivatives. We fabricated the hybrid structure with tunable chemical-sensing properties, achieved by tailoring the structure and composition of graphene oxide and coupling it with titania nanotubes. The parameters of manufactured sensing structures were investigated for hydrogen and ammonia. Our experimental findings indicate that this research may demonstrate an efficient way to enhance the gas-sensing properties of metal oxide nanomaterials for health and safety applications.
{"title":"Study of Gas-Sensing Properties of Titania Nanotubes for Health and Safety Applications","authors":"V. Galstyan, N. Poli, E. Comini","doi":"10.3390/csac2021-10625","DOIUrl":"https://doi.org/10.3390/csac2021-10625","url":null,"abstract":"We studied the preparation and gas-sensing performance of a hybrid nanomaterial based on titania nanotubes and graphene derivatives. We fabricated the hybrid structure with tunable chemical-sensing properties, achieved by tailoring the structure and composition of graphene oxide and coupling it with titania nanotubes. The parameters of manufactured sensing structures were investigated for hydrogen and ammonia. Our experimental findings indicate that this research may demonstrate an efficient way to enhance the gas-sensing properties of metal oxide nanomaterials for health and safety applications.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73101269","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 need to perform in situ sensing measurements lead to the development of innovative and smart field-portable devices. The advantages of such systems are remarkable since they are mainly battery-powered, lightweight and easy to carry and keep. Moreover, field-portable devices are easy to use and are able to give fast sensing responses. In the last few years, many efforts have been made in the development of new performing systems and the advantageous use of nanofibrous materials was assessed. To this purpose, the electrospinning has been recognized as the most powerful and facile technique for generating uniform nanofibers with controlled dimension and morphology. When conductive polymers are electrospun, very interesting electrical properties can be obtained along with the well-known ones that are typical of nanofibers. Among these polymers, polyaniline has been extensively used. In this work, an innovative hybrid material based on polyaniline/polyvinyl acetate/graphene oxide nanofibers was developed and tested as a sensor toward the detection of contaminants in aqueous media. Nanofibers, in the form of a compact mat, were deposited onto a support with suitable electrical contacts. Measurements were performed exploiting the excellent electrical properties of the realized nanofibers in both direct and alternating currents. When a direct current was used, the change in the nanofibers’ resistance value was registered upon exposure to contaminated aqueous solutions and used to determine the presence or absence of contaminants, whereas when tests were performed with an alternating current, the quantitative determination of single species in contaminated solutions was also possible. In this way, by integrating the two different measurement methodologies, an opportunely designed multifunctional portable device will be developed for both qualitative and quantitative contaminants determinations.
{"title":"Conductive Electrospun Nanofibers for Multifunctional Portable Devices","authors":"A. Fotia, P. Frontera, L. Bonaccorsi, A. Malara","doi":"10.3390/csac2021-10634","DOIUrl":"https://doi.org/10.3390/csac2021-10634","url":null,"abstract":"The need to perform in situ sensing measurements lead to the development of innovative and smart field-portable devices. The advantages of such systems are remarkable since they are mainly battery-powered, lightweight and easy to carry and keep. Moreover, field-portable devices are easy to use and are able to give fast sensing responses. In the last few years, many efforts have been made in the development of new performing systems and the advantageous use of nanofibrous materials was assessed. To this purpose, the electrospinning has been recognized as the most powerful and facile technique for generating uniform nanofibers with controlled dimension and morphology. When conductive polymers are electrospun, very interesting electrical properties can be obtained along with the well-known ones that are typical of nanofibers. Among these polymers, polyaniline has been extensively used. In this work, an innovative hybrid material based on polyaniline/polyvinyl acetate/graphene oxide nanofibers was developed and tested as a sensor toward the detection of contaminants in aqueous media. Nanofibers, in the form of a compact mat, were deposited onto a support with suitable electrical contacts. Measurements were performed exploiting the excellent electrical properties of the realized nanofibers in both direct and alternating currents. When a direct current was used, the change in the nanofibers’ resistance value was registered upon exposure to contaminated aqueous solutions and used to determine the presence or absence of contaminants, whereas when tests were performed with an alternating current, the quantitative determination of single species in contaminated solutions was also possible. In this way, by integrating the two different measurement methodologies, an opportunely designed multifunctional portable device will be developed for both qualitative and quantitative contaminants determinations.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74855692","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}
Half-metallic ferromagnetic (HMF) materials demonstrate 100% spin polarization at the Fermi level, making them promising candidates for spintronic sensing applications. In this work, the full potential linearized augmented plane wave (FP-LAPW) density functional theory (DFT) method is used to calculate the electro-magnetic properties of the transition metal perovskite NbScO3 using the generalized gradient approximation (GGA) and the modified Becke-Johnson (mBJ) approximation for the exchange correlations. The electronic band structures for the two spin orientations using GGA, predict NbScO3 to be an HMF with an integer magnetic moment of 2.0 μB and hence a promising candidate for spintronics. The new half metal perovskite shows metallic behavior in the majority spin and semiconducting in the minority spin channel with a direct Γ−Γ band gap of 1.870 eV. The integer magnetic moment of 2.0 μB is also preserved with mBJ exchange potential. The band structure, however, shows indirect gaps R−Γ and X−Γ of 2.023 eV and 0.780 eV in the minority and majority channels, respectively indicating NbScO3 to be a magnetic semiconductor. The results indicate the suitability of NbScO3 for spintronics as the necessary conditions are satisfied.
{"title":"New Half Metal Perovskite NbScO3 for Spintronic Sensing Applications","authors":"A. Ramanathan","doi":"10.3390/csac2021-10628","DOIUrl":"https://doi.org/10.3390/csac2021-10628","url":null,"abstract":"Half-metallic ferromagnetic (HMF) materials demonstrate 100% spin polarization at the Fermi level, making them promising candidates for spintronic sensing applications. In this work, the full potential linearized augmented plane wave (FP-LAPW) density functional theory (DFT) method is used to calculate the electro-magnetic properties of the transition metal perovskite NbScO3 using the generalized gradient approximation (GGA) and the modified Becke-Johnson (mBJ) approximation for the exchange correlations. The electronic band structures for the two spin orientations using GGA, predict NbScO3 to be an HMF with an integer magnetic moment of 2.0 μB and hence a promising candidate for spintronics. The new half metal perovskite shows metallic behavior in the majority spin and semiconducting in the minority spin channel with a direct Γ−Γ band gap of 1.870 eV. The integer magnetic moment of 2.0 μB is also preserved with mBJ exchange potential. The band structure, however, shows indirect gaps R−Γ and X−Γ of 2.023 eV and 0.780 eV in the minority and majority channels, respectively indicating NbScO3 to be a magnetic semiconductor. The results indicate the suitability of NbScO3 for spintronics as the necessary conditions are satisfied.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81774933","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. Martínez-Hernández, Xabier Sandúa, P. J. Rivero, J. Goicoechea, F. Arregui
In this work, an optical fiber sensor based on the localized surface plasmon resonance (LSPR) phenomenon is presented as a powerful tool for the detection of heavy metals (Hg2+). The resultant sensing film was fabricated using a nanofabrication process, known as layer-by-layer embedding (LbL-E) deposition technique. In this sense, both silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized using a synthetic chemical protocol as a function of a strict control of three main parameters: polyelectrolyte concentration, loading agent, and reducing agent. The use of metallic nanostructures as sensing materials is of great interest because well-located absorption peaks associated with their LSPR are obtained at 420 nm (AgNPs) and 530 nm (AuNPs). Both plasmonic peaks provide a stable real-time reference that can be extracted from the spectral response of the optical fiber sensor, giving a reliable monitoring of the Hg2+ concentration.
{"title":"An Optical Fiber Sensor for Hg2+ Detection Based on the LSPR of Silver and Gold Nanoparticles Embedded in a Polymeric Matrix as an Effective Sensing Material","authors":"M. Martínez-Hernández, Xabier Sandúa, P. J. Rivero, J. Goicoechea, F. Arregui","doi":"10.3390/csac2021-10633","DOIUrl":"https://doi.org/10.3390/csac2021-10633","url":null,"abstract":"In this work, an optical fiber sensor based on the localized surface plasmon resonance (LSPR) phenomenon is presented as a powerful tool for the detection of heavy metals (Hg2+). The resultant sensing film was fabricated using a nanofabrication process, known as layer-by-layer embedding (LbL-E) deposition technique. In this sense, both silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized using a synthetic chemical protocol as a function of a strict control of three main parameters: polyelectrolyte concentration, loading agent, and reducing agent. The use of metallic nanostructures as sensing materials is of great interest because well-located absorption peaks associated with their LSPR are obtained at 420 nm (AgNPs) and 530 nm (AuNPs). Both plasmonic peaks provide a stable real-time reference that can be extracted from the spectral response of the optical fiber sensor, giving a reliable monitoring of the Hg2+ concentration.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78256023","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}
N. Komova, Ksenya V. Serebrennikova, A. Berlina, S. M. Pridvorova, A. Zherdev, B. Dzantiev
The application of mercaptosuccinic acid-capped gold nanoparticles as a sensing probe for the colorimetric detection of Fe(III) is reported. The well-dispersed gold nanoparticles (AuNPs) with a diameter of around 20 nm were obtained by a one-step reaction of tetrachloroauratic acid with mercaptosuccinic acid (MSA) as a reducing and capping agent, respectively. Fe(III) reportedly causes the aggregation of prepared MSA-capped AuNPs followed by a change in color and a shift to long wavelengths in the absorbance spectra. The resulting method allows for a visual and spectrophotometric Fe(III) determination with detection limits of 30 ng/mL and 23 ng/mL, respectively. MSA-capped AuNPs have been used as sensing probes for the detection of Fe(III) in drinking water samples with a detection limit that is much lower than the maximum permissible level of Fe(III) specified by official regulations (300 ng/mL).
{"title":"Gold Nanoparticles Functionalized with Mercaptosuccinic Acid as a Means for Detecting Fe(III) Ions","authors":"N. Komova, Ksenya V. Serebrennikova, A. Berlina, S. M. Pridvorova, A. Zherdev, B. Dzantiev","doi":"10.3390/csac2021-10624","DOIUrl":"https://doi.org/10.3390/csac2021-10624","url":null,"abstract":"The application of mercaptosuccinic acid-capped gold nanoparticles as a sensing probe for the colorimetric detection of Fe(III) is reported. The well-dispersed gold nanoparticles (AuNPs) with a diameter of around 20 nm were obtained by a one-step reaction of tetrachloroauratic acid with mercaptosuccinic acid (MSA) as a reducing and capping agent, respectively. Fe(III) reportedly causes the aggregation of prepared MSA-capped AuNPs followed by a change in color and a shift to long wavelengths in the absorbance spectra. The resulting method allows for a visual and spectrophotometric Fe(III) determination with detection limits of 30 ng/mL and 23 ng/mL, respectively. MSA-capped AuNPs have been used as sensing probes for the detection of Fe(III) in drinking water samples with a detection limit that is much lower than the maximum permissible level of Fe(III) specified by official regulations (300 ng/mL).","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75896249","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 use of the electronic nose as a screening device is of great interest in various types of applications, including food quality control and environmental monitoring. It is an easy-to-use device and produces a much faster response than that obtained by classical chemical and microbiological techniques. The reproductivity of nominally identical electronic noses and sensors is critical. Four identical MOX sensors were compared using two different working methods, namely, the temperature modulation mode and isothermal mode. Each sensor was tested with two standard compounds, water and lactic acid, often identified in food matrices, which are potential applications of the electronic nose.
{"title":"Reproductivity Study of Metal Oxide Gas Sensors Using Two Different Temperature Setups","authors":"G. Zambotti, A. Ponzoni","doi":"10.3390/csac2021-10613","DOIUrl":"https://doi.org/10.3390/csac2021-10613","url":null,"abstract":"The use of the electronic nose as a screening device is of great interest in various types of applications, including food quality control and environmental monitoring. It is an easy-to-use device and produces a much faster response than that obtained by classical chemical and microbiological techniques. The reproductivity of nominally identical electronic noses and sensors is critical. Four identical MOX sensors were compared using two different working methods, namely, the temperature modulation mode and isothermal mode. Each sensor was tested with two standard compounds, water and lactic acid, often identified in food matrices, which are potential applications of the electronic nose.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90055849","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}
Tin(IV) oxide nanoparticles in combination with surfactants were used as a sensitive layer in a sensor for hesperidin. The effect of the surfactant’s nature and concentration on the hesperidin response was evaluated. The best parameters were registered in the case of 500 µM cetylpyridinium bromide (CPB) as a dispersive agent. The SEM and electrochemical data confirmed the increase in sensor surface effective area and electron transfer rate. The sensor gave a linear response to hesperidin in the ranges of 0.10–10 and 10–75 µM with a detection limit of 77 nM. The approach was successfully tested on orange juices and validated using ultra-HPLC.
{"title":"Electrode Modified with Tin(IV) Oxide Nanoparticles and Surfactants as Sensitive Sensor for Hesperidin","authors":"E. Yakupova, G. Ziyatdinova","doi":"10.3390/csac2021-10615","DOIUrl":"https://doi.org/10.3390/csac2021-10615","url":null,"abstract":"Tin(IV) oxide nanoparticles in combination with surfactants were used as a sensitive layer in a sensor for hesperidin. The effect of the surfactant’s nature and concentration on the hesperidin response was evaluated. The best parameters were registered in the case of 500 µM cetylpyridinium bromide (CPB) as a dispersive agent. The SEM and electrochemical data confirmed the increase in sensor surface effective area and electron transfer rate. The sensor gave a linear response to hesperidin in the ranges of 0.10–10 and 10–75 µM with a detection limit of 77 nM. The approach was successfully tested on orange juices and validated using ultra-HPLC.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83534214","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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