Chemistry Proceedings最新文献

{"title":"Hydroponics Monitoring through UV-Vis Spectroscopy and Artificial Intelligence: Quantification of Nitrogen, Phosphorous and Potassium","authors":"Aníbal Silva, K. Löfkvist, M. Gilbertsson, E. Os, G. Franken, J. Balendonck, Tatiana M. Pinho, J. Boaventura-Cunha, L. Coelho, P. Jorge, R. Martins","doi":"10.3390/CSAC2021-10448","DOIUrl":"https://doi.org/10.3390/CSAC2021-10448","url":null,"abstract":"In hydroponic cultivation, monitoring and quantification of nutrients is of paramount importance. Precision agriculture has an urgent need for measuring fertilization and plant nutrient uptake. Reliable, robust and accurate sensors for measuring nitrogen (N), phosphorus (P) and potassium (K) are regarded as critical in this process. It is vital to understand nutrients’ interference; thusly, a Hoagland fertilizer solution-based orthogonal experimental design was deployed. Concentration ranges were varied in a target analyte-independent style, as follows: [N] = [103.17–554.85] ppm; [P] = [15.06–515.35] ppm; [K] = [113.78–516.45] ppm, by dilution from individual stock solutions. Quantitative results for N and K, and qualitative results for P were obtained.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76614692","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}

{"title":"Room Temperature Hydrogen Sensing Based on Tapered Optical Fiber Coated with Polyaniline (PANI)","authors":"M. M. Alkhabet, S. Girei, A. Ismail, S. Paiman, N. Arsad, M. Mahdi, M. Yaacob","doi":"10.3390/csac2021-10415","DOIUrl":"https://doi.org/10.3390/csac2021-10415","url":null,"abstract":"This work demonstrates a hydrogen (H2) sensor at room temperature made of tapered optical fibers coated with a polyaniline (PANI) nanofiber. A transducing platform was constructed using a multimode optical fiber (MMF) with a 125 µm cladding and a 62.5 µm core diameter. In order to enhance the light evanescent field surrounding the fiber, the fibers were tapered from 125 µm in diameter to 20 µm in diameter with 10 mm waist and coated PANI using the drop casting technique. Various characterization techniques, such as field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), differential X-ray (XRD), and atomic force microscopy, have been used to establish the PANI’s properties. When H2 is subtracted, the optical properties of the PANI layer change, resulting in a change in light absorption. The fabricated sensor was tested by exposing it to H2 at different concentration from 0.125% to 1%. In this case, the sensitivity, response, and recovery times were 15.928/vol%, 110 s, and 160 s, respectively. The improved hydrogen sensor holds great promise for environmental and industrial applications due to its ability to operate at room temperature.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74517051","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}

{"title":"Development of a Gas Sensor for Eucalyptol Supervision: A Supporting Tool for Extreme Wildfire Management","authors":"C. Magro, Marcelo Morais, Paulo A. Ribeiro, S. Sério, Pedro Vieira, M. Raposo","doi":"10.3390/csac2021-10432","DOIUrl":"https://doi.org/10.3390/csac2021-10432","url":null,"abstract":"Recent research on volatile organic compounds (VOC) released by the heated vegetation has shown that, under specific conditions (e.g., extreme heat, humidity, wind, and topography), VOC might foster wildfire ignition sources and explain sudden changes in fire behavior, particularly in the most susceptible and flammable forests (eucalypt forests). This work aims to develop an electronic nose (e-nose) based on a sensor’s array to monitor the concentration of eucalyptol, the major VOC compound of the Eucalyptus globulus tree. The detection of this target compound was achieved by measuring the impedance spectra of layer-by-layer developed thin films based on polyethyleneimine, poly(allylamine hydrochloride), and graphene oxide, by injecting the analyte into a custom-made vacuum chamber system. The obtained results were analyzed by the principal component analysis method. The developed e-nose sensor was able to distinguish different concentrations in a range from 411 to 1095 ppm.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80872565","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}

{"title":"An Inkjet-Printed Amperometric H2S Sensor for Environmental Applications","authors":"Franc Paré, Rebeca Castro, X. Guimerà, G. Gabriel, M. Baeza","doi":"10.3390/csac2021-10462","DOIUrl":"https://doi.org/10.3390/csac2021-10462","url":null,"abstract":"Hydrogen sulfide (H2S) is a highly toxic chemical capable of causing severe health issues. Due to its environmental impact, it is critical to create effective methods for its monitoring. Inkjet printing technology has become an alternative for sensor fabrication because it is an economic, fast, and reproducible method for mass producing micro-electrodes. Herein, a miniaturized 25 mm2 inkjet-printed amperometric sensor is presented. A gold electrode coupled with a silver track was modified with two inks: single-walled carbon nanotubes (SWCNTs) and a mixture of SCWCNTs and poly(vinyl alcohol) (PVA). Morphological and electrochemical properties were studied, as well as H2S sensor performance. This approach is a suitable option for environmental H2S tracking.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"129 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74896083","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}

{"title":"Locally Linear Embedding as Nonlinear Feature Extraction to Discriminate Liquids with a Cyclic Voltammetric Electronic Tongue","authors":"Jersson X. Leon-Medina, Maribel Anaya, D. Tibaduiza","doi":"10.3390/csac2021-10426","DOIUrl":"https://doi.org/10.3390/csac2021-10426","url":null,"abstract":"Electronic tongues are devices used in the analysis of aqueous matrices for classification or quantification tasks. These systems are composed of several sensors of different materials, a data acquisition unit, and a pattern recognition system. Voltammetric sensors have been used in electronic tongues using the cyclic voltammetry method. By using this method, each sensor yields a voltammogram that relates the response in current to the change in voltage applied to the working electrode. A great amount of data is obtained in the experimental procedure which allows handling the analysis as a pattern recognition application; however, the development of efficient machine-learning-based methodologies is still an open research interest topic. As a contribution, this work presents a novel data processing methodology to classify signals acquired by a cyclic voltammetric electronic tongue. This methodology is composed of several stages such as data normalization through group scaling method and a nonlinear feature extraction step with locally linear embedding (LLE) technique. The reduced-size feature vector input to a k-Nearest Neighbors (k-NN) supervised classifier algorithm. A leave-one-out cross-validation (LOOCV) procedure is performed to obtain the final classification accuracy. The methodology is validated with a data set of five different juices as liquid substances.Two screen-printed electrodes voltametric sensors were used in the electronic tongue. Specifically the materials of their working electrodes were platinum and graphite. The results reached an 80% classification accuracy after applying the developed methodology.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80035084","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}

{"title":"Plasmonic Hydrogel Nanocomposites with Combined Optical and Mechanical Properties for Biochemical Sensing","authors":"Bruno Miranda, R. Moretta, S. D. Martino, P. Dardano, I. Rea, C. Forestiere, L. Stefano","doi":"10.3390/csac2021-10467","DOIUrl":"https://doi.org/10.3390/csac2021-10467","url":null,"abstract":"Localized surface plasmon resonance (LSPR) and metal-enhanced-fluorescence (MEF)-based optical biosensors exhibit unique properties compared to other sensing devices that can be exploited for the design point-of-care (POC) diagnostic tools [1]. Plasmonic devices exploit the capability of noble-metal nanoparticles of absorbing light at a well-defined wavelength. The increasing request for wearable, flexible and easy-to-use diagnostic tools has brought to the development of plasmonic nanocomposites, whose peculiar performances arise from the combination of the optical properties of plasmonic nanoparticles and mechanical properties of the polymeric matrix in which they are embedded [2,3]. An optical platform based on spherical gold nanoparticles (AuNPs) embedded in high molecular weight poly-(ethylene glycol) diacrylate (PEGDA) hydrogel is proposed. PEGDA hydrogel represents a biocompatible, flexible, transparent polymeric network to design wearable, 3D, plasmonic biosensors for the detection of targets with different molecular weights for the early diagnosis of disease. The swelling capability of PEGDA is directly correlated to the plasmonic decoupling of AuNPs embedded within the matrix. A study on the effect of swelling on the optical response of the PEGDA/AuNPs composites was investigated by using a biorecognition layer/target model system. Specifically, after the in situ chemical modification of the AuNPs within the hydrogel, the interaction biotin-streptavidin is monitored within the 3D hydrogel network. Additionally, metal-enhanced fluorescence is observed within the PEGDA/AuNPs nanocomposites, which can be exploited to achieve an ultra-low limit of detection. LSPR signal was monitored via transmission mode customized setup and MEF signal was detected via fluorescence and confocal microscopes. Label-free (LSPR-based) and fluorescence (MEF-based) signals of a high molecular weight target analyte were successfully monitored with relatively high resolutions and low limits of detection compared to the standard polymeric optical platforms available in the literature. The optimized platform could represent a highly reproducible and low-cost novel biosensor to be applied as a POC diagnostic tool in healthcare and food monitoring applications.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88994867","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}

{"title":"Titanium Based Materials for High-Temperature Gas Sensor in Harsh Environment Application","authors":"R. L. Fomekong, B. Saruhan","doi":"10.3390/csac2021-10480","DOIUrl":"https://doi.org/10.3390/csac2021-10480","url":null,"abstract":"Gas selective sensors that are capable of sensing at hot-gas environment are increasingly gaining importance for the monitoring of combustion and thermal processes releasing NO, NO2 and H2 containing hot gases at temperatures exceeding 600 °C. Despite some drawbacks, TiO2 is capable of operating as a gas sensor above 500 °C. In this context, Ni-doped TiO2, Co-doped TiO2 and Rh-doped BaTiO3 have been prepared by oxalate coprecipitation route and fully characterized. Co-doping of TiO2 promotes p-type behavior exhibiting good sensing properties to NO2 while Ni-doping displays the maintenance of n-type behavior and better H2-sensing properties at 600 °C. Rh-doped BaTiO3 shows excellent NO sensing properties at 900 °C.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91396117","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}

{"title":"Poly(bromocresol purple)-Based Voltammetric Sensor for the Simultaneous Quantification of Ferulic Acid and Vanillin","authors":"A. Zhupanova, G. Ziyatdinova","doi":"10.3390/csac2021-10441","DOIUrl":"https://doi.org/10.3390/csac2021-10441","url":null,"abstract":"Natural phenolic antioxidants are extensively studied compounds due to their positive health effect and wide distribution in human diets. The simultaneous occurrence in samples requires selective methods for their determination. Electrochemical sensor based on the polyaminobenzene sulfonic acid functionalized single-walled carbon nanotubes (f-SWCNT) and electropolymerized bromocresol purple has been developed for the simultaneous quantification of ferulic acid and vanillin. The electrode has been characterized by scanning electron microscopy (SEM) and electrochemical methods, and the effectivity of the developed modifier has been confirmed. Thus, the novel sensitive voltammetric sensor is simple to fabricate, reliable, cost-effective, and can be applied for foodstuff screening.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90273836","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}

{"title":"Applied Voltage Effect in Lbl Sensors While Detecting 17α-Ethinylestradiol in Water Samples","authors":"Paulo M. Zagalo, C. Magro, P. Ribeiro, M. Raposo","doi":"10.3390/csac2021-10460","DOIUrl":"https://doi.org/10.3390/csac2021-10460","url":null,"abstract":"The effect of the applied voltage on impedance spectra, measured on sensors based on solid supports with interdigitated electrodes (IDE) that are either covered or not with a layer-by-layer film prepared with polyethylenimine and poly (sodium 4-styrenesulfonate), was analyzed to detect 17α-ethinylestradiol(EE2) in mineral water and tap water. The results show that the sensor response is strongly affected by the applied voltage, the presence of film, and the water matrix, meaning that electrochemical reactions develop near the IDE. However, for low values of applied voltage, the sensor response is reproducible with negligible electrochemical reactions, allowing us to conclude that 25 mV is the appropriate voltage.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79062538","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}

{"title":"Implementation of Metallic Film Electrodes for Catalytic Adsorptive Stripping Voltammetric Determination of Germanium(IV)","authors":"A. Królicka, J. Zarębski, A. Bobrowski","doi":"10.3390/csac2021-10484","DOIUrl":"https://doi.org/10.3390/csac2021-10484","url":null,"abstract":"In the present work, it has been shown that bismuth film electrodes deposited on screen-printed carbon supports could be successfully used to provide well-shaped, sensitive and reproducible catalytic adsorptive stripping signals of Ge(IV) in the presence of catechol and V(IV)-HEDTA (HEDTA-N-hydroxyethyl-ethylene diamine-triacetic acid) complex.","PeriodicalId":9815,"journal":{"name":"Chemistry Proceedings","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73910329","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}