This study is dedicated to molecularly imprinted polymer-based sensor development for methylene blue detection. The sensor was designed by molecular imprinting of polypyrrole with phenothiazine derivative methylene blue (MB) as a template molecule. The molecularly imprinted polymer (MIP) was deposited directly on the surface of the indium tin oxide-coated glass electrode by potential cycling. Different deposition conditions, the layer’s durability, and thickness impact were analysed. The working electrodes were coated with molecularly imprinted and non-imprinted polymer layers. Potential pulse chronoamperometry and cyclic voltammetry were used to study these layers. Scanning electron microscopy was used to determine the surface morphology of the polymer layers. The change in optical absorption was used as an analytical tool to evaluate the capability of the MIP layer to adsorb MB. Selectivity was monitored by tracking the optical absorption changes in the presence of Azure A. In the case of MB adsorption, linearity was observed at all evaluated calibration plots in the concentration range from 0.1 μM to 10 mM. The novelty of this article is based on the methodology in the fabrication process of the sensors for MB, where MB retains its native (non-polymerised) form during the deposition of the MIP composite.
{"title":"Towards Molecularly Imprinted Polypyrrole-Based Sensor for the Detection of Methylene Blue","authors":"Raimonda Boguzaite, Greta Pilvenyte, Vilma Ratautaite, Ernestas Brazys, Almira Ramanaviciene, Arunas Ramanavicius","doi":"10.3390/chemosensors11110549","DOIUrl":"https://doi.org/10.3390/chemosensors11110549","url":null,"abstract":"This study is dedicated to molecularly imprinted polymer-based sensor development for methylene blue detection. The sensor was designed by molecular imprinting of polypyrrole with phenothiazine derivative methylene blue (MB) as a template molecule. The molecularly imprinted polymer (MIP) was deposited directly on the surface of the indium tin oxide-coated glass electrode by potential cycling. Different deposition conditions, the layer’s durability, and thickness impact were analysed. The working electrodes were coated with molecularly imprinted and non-imprinted polymer layers. Potential pulse chronoamperometry and cyclic voltammetry were used to study these layers. Scanning electron microscopy was used to determine the surface morphology of the polymer layers. The change in optical absorption was used as an analytical tool to evaluate the capability of the MIP layer to adsorb MB. Selectivity was monitored by tracking the optical absorption changes in the presence of Azure A. In the case of MB adsorption, linearity was observed at all evaluated calibration plots in the concentration range from 0.1 μM to 10 mM. The novelty of this article is based on the methodology in the fabrication process of the sensors for MB, where MB retains its native (non-polymerised) form during the deposition of the MIP composite.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"192 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136377261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-26DOI: 10.3390/chemosensors11110550
Shuja Bashir Malik, Fatima Ezahra Annanouch, Eduard Llobet
In this work, efficient hydrogen gas sensors based on multilayered p-type bare MoS2 and Pd-decorated MoS2 were fabricated. MoS2 was deposited onto alumina transducers using an airbrushing technique to be used as a sensing material. Aerosol-assisted chemical vapor deposition (AACVD) was used to decorate layered MoS2 with Pd nanoparticles at 250 °C. The bare and Pd-decorated MoS2 was characterized using field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Raman spectroscopy. The characterization results reveal the multilayered crystalline structure of MoS2 with successful Pd decoration. The size of the Pd nanoparticles ranges from 15 nm to 23 nm. Gas sensing studies reveal that a maximum response of 55% is achieved for Pd-decorated MoS2 operated at 150 °C to 100 ppm of H2, which is clearly below the explosive limit (4%) in air. The higher sensitivity due to Pd nanoparticle decoration was owed to a spillover effect. This study reveals that the sensitivity of the sensors is highly dependent on the amount of Pd decoration. Moreover, sensor responses increase slightly when exposed to 50% relative humidity (RH at 25 °C).
本文制备了基于多层p型裸MoS2和pd修饰MoS2的高效氢气传感器。利用喷枪技术将MoS2沉积在氧化铝换能器上作为传感材料。采用气溶胶辅助化学气相沉积(AACVD)技术，在250℃下用Pd纳米粒子修饰层状二硫化钼。利用场发射扫描电镜(FESEM)、高分辨率透射电镜(HR-TEM)、x射线衍射(XRD)和拉曼光谱对裸态和pd修饰的二硫化钼进行了表征。表征结果表明，经过Pd修饰的MoS2具有多层晶体结构。钯纳米粒子的尺寸在15 ~ 23纳米之间。气体传感研究表明，在150°C和100 ppm H2下，pd修饰的MoS2的最大响应率为55%，明显低于空气中的爆炸极限(4%)。钯纳米粒子修饰的高灵敏度是由于溢出效应。该研究表明，传感器的灵敏度高度依赖于Pd装饰量。此外，当暴露于50%的相对湿度(RH at 25°C)时，传感器响应略有增加。
{"title":"Pd-Nanoparticle-Decorated Multilayered MoS2 Sheets for Highly Sensitive Hydrogen Sensing","authors":"Shuja Bashir Malik, Fatima Ezahra Annanouch, Eduard Llobet","doi":"10.3390/chemosensors11110550","DOIUrl":"https://doi.org/10.3390/chemosensors11110550","url":null,"abstract":"In this work, efficient hydrogen gas sensors based on multilayered p-type bare MoS2 and Pd-decorated MoS2 were fabricated. MoS2 was deposited onto alumina transducers using an airbrushing technique to be used as a sensing material. Aerosol-assisted chemical vapor deposition (AACVD) was used to decorate layered MoS2 with Pd nanoparticles at 250 °C. The bare and Pd-decorated MoS2 was characterized using field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Raman spectroscopy. The characterization results reveal the multilayered crystalline structure of MoS2 with successful Pd decoration. The size of the Pd nanoparticles ranges from 15 nm to 23 nm. Gas sensing studies reveal that a maximum response of 55% is achieved for Pd-decorated MoS2 operated at 150 °C to 100 ppm of H2, which is clearly below the explosive limit (4%) in air. The higher sensitivity due to Pd nanoparticle decoration was owed to a spillover effect. This study reveals that the sensitivity of the sensors is highly dependent on the amount of Pd decoration. Moreover, sensor responses increase slightly when exposed to 50% relative humidity (RH at 25 °C).","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134906684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-24DOI: 10.3390/chemosensors11110548
Elias Bou-Maroun
This review aims to elucidate recent developments in electrochemical sensors that use functionalized carbon electrodes with molecularly imprinted polymers (MIPs) for the selective detection of organic compounds in diverse fields including pharmacy, food safety, environmental monitoring of pollutants, and biomedical analysis. The main targets include explosive compounds, dyes, antioxidants, disease biomarkers, pharmaceuticals, antibiotics, allergens, pesticides, and viruses. Following a brief overview of the molecular imprinting principle, the most significant applications are explored. The selection of the functional monomer is subsequently discussed. Notably, various types of carbon electrodes are presented, with a particular emphasis on screen-printed carbon electrodes. The most commonly employed techniques for MIP deposition such as electropolymerization, drop casting, and chemical grafting are introduced and discussed. Electrochemical transduction techniques like cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy are presented. Lastly, the review concludes by examining potential future directions and primary limitations concerning carbon electrodes modified with MIPs.
{"title":"Carbon Electrode Modified with Molecularly Imprinted Polymers for the Development of Electrochemical Sensor: Application to Pharmacy, Food Safety, Environmental Monitoring, and Biomedical Analysis","authors":"Elias Bou-Maroun","doi":"10.3390/chemosensors11110548","DOIUrl":"https://doi.org/10.3390/chemosensors11110548","url":null,"abstract":"This review aims to elucidate recent developments in electrochemical sensors that use functionalized carbon electrodes with molecularly imprinted polymers (MIPs) for the selective detection of organic compounds in diverse fields including pharmacy, food safety, environmental monitoring of pollutants, and biomedical analysis. The main targets include explosive compounds, dyes, antioxidants, disease biomarkers, pharmaceuticals, antibiotics, allergens, pesticides, and viruses. Following a brief overview of the molecular imprinting principle, the most significant applications are explored. The selection of the functional monomer is subsequently discussed. Notably, various types of carbon electrodes are presented, with a particular emphasis on screen-printed carbon electrodes. The most commonly employed techniques for MIP deposition such as electropolymerization, drop casting, and chemical grafting are introduced and discussed. Electrochemical transduction techniques like cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy are presented. Lastly, the review concludes by examining potential future directions and primary limitations concerning carbon electrodes modified with MIPs.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135266186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-22DOI: 10.3390/chemosensors11100547
Panna Vezse, Ádám Golcs, Tünde Tóth, Péter Huszthy
This study aims to introduce a fluorescence-based chemosensing method for Zn2+ in aqueous suspensions and untreated surface waters, conditions which generally hinder the application of conventional optochemical sensing platforms. A macrocyclic fluoroionophore was covalently bonded to a silica-coated magnetic nanoparticle and applied according to a predetermined protocol for analyzing trace amounts of Zn2+ under rarely investigated conditions. Utilizing the reversible complexation of the immobilized fluoroionophore, rapid regeneration was carried out via simple acidification after the magnetic-assisted solid-phase extraction of the particles. Forming inclusion complexes with Zn2+ with the receptor units of the particles leads to a significant enhancement in fluorescence intensity at 370 nm, above the detection limit of 5 ppb, with a dynamic linear range of quantification of 15–3000 ppb in a pH range of 5.5–7.5. Practical applicability was confirmed by analyzing untreated river water and an aqueous suspension of pumpkin seed flour as real and relevant heterogeneous multicomponent samples of predetermined sample composition and natural Zn2+ content. Our practical approach aims to broaden the applicability range of optochemical sensing platforms for Zn2+.
{"title":"Contamination- and Perturbation-Free Fluorescent Monitoring of Zn2+ in Suspensions using Crown Ether-Functionalized Magnetic Nanoparticles","authors":"Panna Vezse, Ádám Golcs, Tünde Tóth, Péter Huszthy","doi":"10.3390/chemosensors11100547","DOIUrl":"https://doi.org/10.3390/chemosensors11100547","url":null,"abstract":"This study aims to introduce a fluorescence-based chemosensing method for Zn2+ in aqueous suspensions and untreated surface waters, conditions which generally hinder the application of conventional optochemical sensing platforms. A macrocyclic fluoroionophore was covalently bonded to a silica-coated magnetic nanoparticle and applied according to a predetermined protocol for analyzing trace amounts of Zn2+ under rarely investigated conditions. Utilizing the reversible complexation of the immobilized fluoroionophore, rapid regeneration was carried out via simple acidification after the magnetic-assisted solid-phase extraction of the particles. Forming inclusion complexes with Zn2+ with the receptor units of the particles leads to a significant enhancement in fluorescence intensity at 370 nm, above the detection limit of 5 ppb, with a dynamic linear range of quantification of 15–3000 ppb in a pH range of 5.5–7.5. Practical applicability was confirmed by analyzing untreated river water and an aqueous suspension of pumpkin seed flour as real and relevant heterogeneous multicomponent samples of predetermined sample composition and natural Zn2+ content. Our practical approach aims to broaden the applicability range of optochemical sensing platforms for Zn2+.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135461246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-21DOI: 10.3390/chemosensors11100545
Igor Lukić, Ivana Horvat, Sanja Radeka, Urska Vrhovsek
To investigate the effects of the application of bentonite, tannins, and their combination in alcoholic fermentation, Malvazija istarska (Vitis vinifera L.) white grape must was treated with 95 g/L of bentonite, 25 g/L of a hydrolysable tannin preparation, while the third treatment received the aforementioned doses of both agents. Control grape must was fermented without bentonite and exogenous tannins. All of the produced wines were additionally fined after fermentation with doses of bentonite needed to achieve complete protein stability. Wines were analyzed both after fermentation and after additional bentonite fining. Standard physicochemical parameters were determined by the OIV methods, and phenols were analyzed by high-performance liquid chromatography with diode-array detection (HPLC-DAD), while the concentrations of free and bound volatile aroma compounds were obtained after solid-phase extraction (SPE) followed by gas chromatography–mass spectrometry (GC-MS). Bentonite and tannins in fermentation generally reduced the total dose of bentonite needed for complete stabilization. Treatments with bentonite slightly decreased the concentration of total dry extract, while tannins preserved total acidity. The negative effect of bentonite on flavonoids was more severe. Tannins in fermentation preserved more hydroxycinnamoyltartaric acids with respect to control wine, and this effect was additionally enhanced by bentonite. Volatile and bound aroma composition was affected by all the treatments, while the addition of tannins resulted in higher concentrations of several important odoriferous esters, such as ethyl hexanoate, ethyl decanoate, and hexyl acetate. Additional fining with bentonite to complete protein stabilization annulled some of the positive effects observed after fermentation.
{"title":"Solid-Phase Extraction Followed by Gas Chromatography–Mass Spectrometry for Revealing the Effects of the Application of Bentonite, Tannins, and Their Combination during Fermentation in the Production of White Wine","authors":"Igor Lukić, Ivana Horvat, Sanja Radeka, Urska Vrhovsek","doi":"10.3390/chemosensors11100545","DOIUrl":"https://doi.org/10.3390/chemosensors11100545","url":null,"abstract":"To investigate the effects of the application of bentonite, tannins, and their combination in alcoholic fermentation, Malvazija istarska (Vitis vinifera L.) white grape must was treated with 95 g/L of bentonite, 25 g/L of a hydrolysable tannin preparation, while the third treatment received the aforementioned doses of both agents. Control grape must was fermented without bentonite and exogenous tannins. All of the produced wines were additionally fined after fermentation with doses of bentonite needed to achieve complete protein stability. Wines were analyzed both after fermentation and after additional bentonite fining. Standard physicochemical parameters were determined by the OIV methods, and phenols were analyzed by high-performance liquid chromatography with diode-array detection (HPLC-DAD), while the concentrations of free and bound volatile aroma compounds were obtained after solid-phase extraction (SPE) followed by gas chromatography–mass spectrometry (GC-MS). Bentonite and tannins in fermentation generally reduced the total dose of bentonite needed for complete stabilization. Treatments with bentonite slightly decreased the concentration of total dry extract, while tannins preserved total acidity. The negative effect of bentonite on flavonoids was more severe. Tannins in fermentation preserved more hydroxycinnamoyltartaric acids with respect to control wine, and this effect was additionally enhanced by bentonite. Volatile and bound aroma composition was affected by all the treatments, while the addition of tannins resulted in higher concentrations of several important odoriferous esters, such as ethyl hexanoate, ethyl decanoate, and hexyl acetate. Additional fining with bentonite to complete protein stabilization annulled some of the positive effects observed after fermentation.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"120 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135511840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-21DOI: 10.3390/chemosensors11100546
Seyedeh Rojin Shariati Pour, Donato Calabria, Afsaneh Emamiamin, Elisa Lazzarini, Andrea Pace, Massimo Guardigli, Martina Zangheri, Mara Mirasoli
Analytical chemistry applied to medical and diagnostic analysis has recently focused on the development of cost-effective biosensors able to monitor the health status or to assess the level of specific biomarkers that can be indicative of several diseases. The improvement of technologies relating to the possibility of the non-invasive sampling of biological fluids, as well as sensors for the detection of analytical signals and the computational capabilities of the systems routinely employed in everyday life (e.g., smartphones, computers, etc.), makes the complete integration of self-standing analytical devices more accessible. This review aims to discuss the biosensors that have been proposed in the last five years focusing on two principal detecting approaches, optical and electrochemical, which have been employed for quantifying different kinds of target analytes reaching detection limits below the clinical sample levels required. These detection principles applied to point-of-care (POC) devices have been extensively reported in literature, and even the limited examples found on the market are based on these strategies. This work will show the latest innovations considering the integration of optical and electrochemical detection with the most commonly reported analytical platforms for POC applications such as paper-based or wearable and implantable devices.
{"title":"Electrochemical vs. Optical Biosensors for Point-of-Care Applications: A Critical Review","authors":"Seyedeh Rojin Shariati Pour, Donato Calabria, Afsaneh Emamiamin, Elisa Lazzarini, Andrea Pace, Massimo Guardigli, Martina Zangheri, Mara Mirasoli","doi":"10.3390/chemosensors11100546","DOIUrl":"https://doi.org/10.3390/chemosensors11100546","url":null,"abstract":"Analytical chemistry applied to medical and diagnostic analysis has recently focused on the development of cost-effective biosensors able to monitor the health status or to assess the level of specific biomarkers that can be indicative of several diseases. The improvement of technologies relating to the possibility of the non-invasive sampling of biological fluids, as well as sensors for the detection of analytical signals and the computational capabilities of the systems routinely employed in everyday life (e.g., smartphones, computers, etc.), makes the complete integration of self-standing analytical devices more accessible. This review aims to discuss the biosensors that have been proposed in the last five years focusing on two principal detecting approaches, optical and electrochemical, which have been employed for quantifying different kinds of target analytes reaching detection limits below the clinical sample levels required. These detection principles applied to point-of-care (POC) devices have been extensively reported in literature, and even the limited examples found on the market are based on these strategies. This work will show the latest innovations considering the integration of optical and electrochemical detection with the most commonly reported analytical platforms for POC applications such as paper-based or wearable and implantable devices.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135511539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-20DOI: 10.3390/chemosensors11100544
Elaiyappillai Elanthamilan, Sea-Fue Wang
The extensive use of antibiotics has rapidly spread antibiotic resistance, which poses significant health risks to humans. Unfortunately, despite this pressing issue, there is still a lack of a reliable on-site detection method for the residues of antibiotics, such as nilutamide (Nlu). Consequently, there is an urgent need to develop and perfect such a detection method to effectively monitor and control antibiotic residues. In this study, the hydrothermal development of copper-metal-organic framework (Cu-MOF) polyhedrons on the functionalized carbon nanofiber (f-CNF) matrix allowed for the detection of Nlu in biological liquids via a sensitive amperometry technique. Further electrochemical detection of Nlu took place with the cyclic voltammetry (CV) technique Cu-MOF/f-CNF. Analytical and spectroscopic approaches were used to confirm the successful synthesis of Cu-MOF/f-CNF. The prepared material was decorated on the surface of GCE and performed as an electrochemical Nlu sensor, with a broad linear range of 0.01 to 141.4 μM and 2 nM as a lower limit of detection. In addition, the composites had a large surface area and many dedicated sites, which improved electrocatalysis. In practical applications, Cu-MOF/f-CNF/GCE provides a novel strategy for improving electrochemical activity by measuring Nlu concentrations in biological samples.
{"title":"Signal Amplification for Detection of Nilutamide in Three-Dimensional Electrochemical Sensor Using Copper Metal–Organic Framework Decorated Carbon Nanofibers","authors":"Elaiyappillai Elanthamilan, Sea-Fue Wang","doi":"10.3390/chemosensors11100544","DOIUrl":"https://doi.org/10.3390/chemosensors11100544","url":null,"abstract":"The extensive use of antibiotics has rapidly spread antibiotic resistance, which poses significant health risks to humans. Unfortunately, despite this pressing issue, there is still a lack of a reliable on-site detection method for the residues of antibiotics, such as nilutamide (Nlu). Consequently, there is an urgent need to develop and perfect such a detection method to effectively monitor and control antibiotic residues. In this study, the hydrothermal development of copper-metal-organic framework (Cu-MOF) polyhedrons on the functionalized carbon nanofiber (f-CNF) matrix allowed for the detection of Nlu in biological liquids via a sensitive amperometry technique. Further electrochemical detection of Nlu took place with the cyclic voltammetry (CV) technique Cu-MOF/f-CNF. Analytical and spectroscopic approaches were used to confirm the successful synthesis of Cu-MOF/f-CNF. The prepared material was decorated on the surface of GCE and performed as an electrochemical Nlu sensor, with a broad linear range of 0.01 to 141.4 μM and 2 nM as a lower limit of detection. In addition, the composites had a large surface area and many dedicated sites, which improved electrocatalysis. In practical applications, Cu-MOF/f-CNF/GCE provides a novel strategy for improving electrochemical activity by measuring Nlu concentrations in biological samples.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135617720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Volatile organic compounds (VOCs) from wood and wood composites are important contributors to odor profiles of indoor environments and can significantly influence human health and well-being. GC-MS/FID and gas chromatography (GC) with olfactometric detection (GC-O) are employed for the identification and characterization of odorants. Four different sample preparation methods are evaluated on wood strands and isocyanate adhesive–based oriented strand boards (OSBs) made from Pinus sylvestris L.: among these, dynamic headspace extraction thermal desorption ((dynamic) HS-TD), head space solid phase microextraction (HS-SPME), head space solid phase microextraction Arrow (HS-SPME Arrow), and liquid injection of a CH2Cl2 solvent extract. The olfactometric investigation revealed over 30 odor-active substances of cyclic and acyclic monoterpene, monoterpenoid ketone, monoterpenoid aldehyde, monoterpenoid alcohol, monoterpenoid ester, aliphatic aldehyde, alcohol, and acid and phenolic chemistry. Compared to liquid injection, (dynamic) HS-TD was found to result in a similar number of odorants (20 vs. 24), whereas HS SPME Arrow shows good performance with minimal instrumental effort, notably for monoterpene and aldehyde compounds. Native wood vs. OSB showed high concentrations of saturated and unsaturated aldehydes for the wood board sample. These findings demonstrate the capability of headspace methods for odorant detection and their suitability for standardization towards a database for wood and wood composites.
{"title":"Method Comparison for the Identification and Characterization of Odorants from Scots Pine (Pinus sylvestris L.) and Oriented Strand Boards (OSB) Made Thereof by GC-MS and GC-FID/O Using Different Headspace Techniques","authors":"Valentin Schierer, Cornelia Rieder-Gradinger, Erwin Rosenberg","doi":"10.3390/chemosensors11100543","DOIUrl":"https://doi.org/10.3390/chemosensors11100543","url":null,"abstract":"Volatile organic compounds (VOCs) from wood and wood composites are important contributors to odor profiles of indoor environments and can significantly influence human health and well-being. GC-MS/FID and gas chromatography (GC) with olfactometric detection (GC-O) are employed for the identification and characterization of odorants. Four different sample preparation methods are evaluated on wood strands and isocyanate adhesive–based oriented strand boards (OSBs) made from Pinus sylvestris L.: among these, dynamic headspace extraction thermal desorption ((dynamic) HS-TD), head space solid phase microextraction (HS-SPME), head space solid phase microextraction Arrow (HS-SPME Arrow), and liquid injection of a CH2Cl2 solvent extract. The olfactometric investigation revealed over 30 odor-active substances of cyclic and acyclic monoterpene, monoterpenoid ketone, monoterpenoid aldehyde, monoterpenoid alcohol, monoterpenoid ester, aliphatic aldehyde, alcohol, and acid and phenolic chemistry. Compared to liquid injection, (dynamic) HS-TD was found to result in a similar number of odorants (20 vs. 24), whereas HS SPME Arrow shows good performance with minimal instrumental effort, notably for monoterpene and aldehyde compounds. Native wood vs. OSB showed high concentrations of saturated and unsaturated aldehydes for the wood board sample. These findings demonstrate the capability of headspace methods for odorant detection and their suitability for standardization towards a database for wood and wood composites.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135730525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory condition that often goes undiagnosed despite the availability of spirometry for diagnosis, and its exact prevalence remains uncertain. Exhaled breath has been proposed as a source of relevant health information, particularly Volatile Organic Compounds (VOCs), which can be easily obtained and applied in clinical practice. In this study, exhaled breath samples were collected from patients diagnosed with COPD of varying severity during their stable condition using specialized RTubeVOC tubes. Volatile compounds from the air samples were extracted using a 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and the analysis was performed using gas chromatography/mass spectrometry (GC/MS) technique. The patients were divided into two groups based on their history of exacerbations, and the aim was to identify VOCs associated with the risk of future COPD exacerbation, thus allowing for more personalized and objective COPD treatment. Blood eosinophil content was also taken into consideration. A panel of distinguishing mass-spectral features was identified between the two patient groups. The discriminating exhaled molecules were heptane 2,2,4,6,6-pentamethyl, gamma-terpinene, 2-ethylhexanol, and undecane demonstrating the potential of analyzing VOCs in exhaled breath for the detection and management of COPD, offering a promising avenue to improve COPD management and treatment approaches.
{"title":"Solid-Phase Microextraction (SPME) and Gas Chromatographic/Mass Spectrometry in Chronic Obstructive Pulmonary Disease (COPD): A Chemometric Approach","authors":"Loukia Lypirou, Christos Chronis, Konstantinos Exarchos, Konstantinos Kostikas, Vasilios Sakkas","doi":"10.3390/chemosensors11100542","DOIUrl":"https://doi.org/10.3390/chemosensors11100542","url":null,"abstract":"Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory condition that often goes undiagnosed despite the availability of spirometry for diagnosis, and its exact prevalence remains uncertain. Exhaled breath has been proposed as a source of relevant health information, particularly Volatile Organic Compounds (VOCs), which can be easily obtained and applied in clinical practice. In this study, exhaled breath samples were collected from patients diagnosed with COPD of varying severity during their stable condition using specialized RTubeVOC tubes. Volatile compounds from the air samples were extracted using a 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and the analysis was performed using gas chromatography/mass spectrometry (GC/MS) technique. The patients were divided into two groups based on their history of exacerbations, and the aim was to identify VOCs associated with the risk of future COPD exacerbation, thus allowing for more personalized and objective COPD treatment. Blood eosinophil content was also taken into consideration. A panel of distinguishing mass-spectral features was identified between the two patient groups. The discriminating exhaled molecules were heptane 2,2,4,6,6-pentamethyl, gamma-terpinene, 2-ethylhexanol, and undecane demonstrating the potential of analyzing VOCs in exhaled breath for the detection and management of COPD, offering a promising avenue to improve COPD management and treatment approaches.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135888751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gas sensing holds great significance in environment monitoring, real–time security alerts and clinical diagnosis, which require sensing technology to distinguish various target molecules with extreme sensitivity and selectivity. Surface–enhanced Raman spectroscopy (SERS) has great potential in gas sensing for its single molecule sensitivity and fingerprint specificity. However, different from molecule sensing in solutions, SERS detection of gas often suffers from low sensitivity as gas molecules usually display a low Raman cross–section and poor affinity on traditional noble metal nanoparticle (NMNP)–based substrates. Therefore, much effort has been made to solve these problems. Fortunately, the appearance of metal–organic frameworks (MOFs) has shed new light on this direction. Due to the unique functional characteristics of MOFs, such as controllable pore size/shape, structural diversity and large specific surface area, SERS substrates based on MOFs can achieve high sensitivity, excellent selectivity and good stability. Although several reviews on MOF–based SERS substrates have been reported, few focus on gas sensing, which is a great challenge. Here, we mainly review the latest research progress on SERS substrates based on different MOFs. Sensitive and active SERS substrates can be prepared according to the unique advantages of MOFs with different metal centers. Then, we focus on composite SERS substrates based on different MOFs and NMNPs and summarize the application of composite SERS substrates in gas sensing. Finally, the future difficulties and potential possibilities of SERS substrates based on MOFs and NMNPs for gas sensing are discussed.
{"title":"Metal–Organic Frameworks–Based Surface–Enhanced Raman Scattering Substrates for Gas Sensing","authors":"Weiqing Xiong, Xiaoyan Wang, Haiquan Liu, Yue Zhang","doi":"10.3390/chemosensors11100541","DOIUrl":"https://doi.org/10.3390/chemosensors11100541","url":null,"abstract":"Gas sensing holds great significance in environment monitoring, real–time security alerts and clinical diagnosis, which require sensing technology to distinguish various target molecules with extreme sensitivity and selectivity. Surface–enhanced Raman spectroscopy (SERS) has great potential in gas sensing for its single molecule sensitivity and fingerprint specificity. However, different from molecule sensing in solutions, SERS detection of gas often suffers from low sensitivity as gas molecules usually display a low Raman cross–section and poor affinity on traditional noble metal nanoparticle (NMNP)–based substrates. Therefore, much effort has been made to solve these problems. Fortunately, the appearance of metal–organic frameworks (MOFs) has shed new light on this direction. Due to the unique functional characteristics of MOFs, such as controllable pore size/shape, structural diversity and large specific surface area, SERS substrates based on MOFs can achieve high sensitivity, excellent selectivity and good stability. Although several reviews on MOF–based SERS substrates have been reported, few focus on gas sensing, which is a great challenge. Here, we mainly review the latest research progress on SERS substrates based on different MOFs. Sensitive and active SERS substrates can be prepared according to the unique advantages of MOFs with different metal centers. Then, we focus on composite SERS substrates based on different MOFs and NMNPs and summarize the application of composite SERS substrates in gas sensing. Finally, the future difficulties and potential possibilities of SERS substrates based on MOFs and NMNPs for gas sensing are discussed.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":"206 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136033003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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