{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,15]],"date-time":"2026-03-15T06:05:45Z","timestamp":1773554745303,"version":"3.50.1"},"reference-count":63,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2020,12,3]],"date-time":"2020-12-03T00:00:00Z","timestamp":1606953600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Higher Education of Malaysia","award":["FRGS\/1\/2018\/STG01\/UKM\/02\/14"],"award-info":[{"award-number":["FRGS\/1\/2018\/STG01\/UKM\/02\/14"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>An all-solid-state potentiometric electrode system for aluminium ion determination was developed with a new aluminium ion sensor as the working electrode based on a new ionophore for aluminium ion, 1,1\u2032-[(methylazanediyl)bis(ethane-2,1-diyl)]bis[3-(naphthalen-1-yl)thiourea] (ACH). The reference electrode was a potassium ion sensor, which acts as a pseudo-reference. Both electrodes were made from Ag\/AgCl screen-print electrodes fabricated from a non-plasticized and photocurable poly(n-butyl acrylate) membrane that contained various other membrane components. The pseudo-reference potential based on the potassium ion sensor was fixed in 0.050 M KNO3, and such concentration of K+ ion did not interfere with the measurement of the Al3+ ion using the aluminium sensor. With such a pseudo-reference and in the presence of 0.050 M KNO3 as a background medium, the aluminium sensor measured changes of aluminium ion concentrations linearly from 10\u22126 to 10\u22122 M Al3+ ion with a Nernstian response of 17.70 \u00b1 0.13 mV\/decade. A low detection limit of 2.45 \u00d7 10\u22127 M was achieved with this all-solid-state potentiometric system. The aluminium sensor was insensitive to pH effects from 2.0 to 8.0 with a response time of less than 50 s. Under optimum conditions, a lifetime of 49 days was achieved with good sensor selectivity, reversibility, repeatability, and reproducibility. The all-solid-state electrode system was applied to analyze the Al3+ ion content of water samples from a water treatment plant. Compared with the conventional potentiometric detection system for aluminium ions, the new all-solid-state aluminium ion sensor incorporating a pseudo-reference from the potassium sensor demonstrated similar analytical performance. It thus provided a convenient means of aluminium content analysis in water treatment plants.<\/jats:p>","DOI":"10.3390\/s20236898","type":"journal-article","created":{"date-parts":[[2020,12,3]],"date-time":"2020-12-03T11:15:43Z","timestamp":1606994143000},"page":"6898","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["A New and All-Solid-State Potentiometric Aluminium Ion Sensor for Water Analysis"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2168-5358","authenticated-orcid":false,"given":"Kook Shih","family":"Ying","sequence":"first","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lee Yook","family":"Heng","sequence":"additional","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1235-4290","authenticated-orcid":false,"given":"Nurul Izzaty","family":"Hassan","sequence":"additional","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Siti Aishah","family":"Hasbullah","sequence":"additional","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1007\/s12403-019-00297-w","article-title":"Non-carcinogenic health risk assessment of aluminium ingestion via drinking water in Malaysia","volume":"11","author":"Ahmed","year":"2019","journal-title":"Expo. Health"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Yang, M., Tan, L., Xu, Y., Zhao, Y., Cheng, F., and Ye, S. (2015). Effect of low pH and aluminium toxicity on the photosynthetic characteristics of different fast-growing eucalyptus vegetatively propagated clones. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0130963"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1089\/ees.2016.0290","article-title":"Accumulation of Fe-Al by Scirpus grossus grown in synthetic bauxite mining wastewater and identification of resistant rhizobacteria","volume":"34","author":"Ismail","year":"2016","journal-title":"Environ. Eng. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1016\/j.saa.2015.07.095","article-title":"Two Schiff-base fluorescent sensors for selective sensing of aluminium (III): Experimental and computational studies","volume":"152","author":"Qin","year":"2016","journal-title":"Spectrochim. Acta\u2014Part A Mol. Biomol. Spectrosc."},{"key":"ref_5","unstructured":"Habs, H., Simon, B., Thiedemann, K.U., and Howe, P. (1997). Aluminium, World Health Organization, International Programme on Chemical Safety (Environmental Health Criteria 194)."},{"key":"ref_6","unstructured":"Fawell, J.K. (2010). Aluminium in Drinking-Water, World Health Organization."},{"key":"ref_7","unstructured":"Gordon, B., Callan, P., Vickers, C., Tritscher, A., Perez, M., Zaim, M., Jamie, B., and Bos, R. (2011). Guideline for Drinking-Water Quality, World Health Organization. [4th ed.]."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"801","DOI":"10.1016\/j.talanta.2015.06.011","article-title":"Recent developments, characteristics and potential applications of screen-printed electrodes in pharmaceutical and biological analysis","volume":"146","author":"Couto","year":"2015","journal-title":"Talanta"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2657","DOI":"10.17576\/jsm-2018-4711-08","article-title":"A new copper ionophore N1, N3-bis[[3,5-bis(trifluoromethyl)phenyl]carbamothioyl]isophtalamide for potentiometric sensor","volume":"47","author":"Kook","year":"2018","journal-title":"Sains Malays."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3613","DOI":"10.1007\/s00216-011-4689-9","article-title":"Solid-state reference electrodes based on carbon nanotubes and polyacrylate membranes","volume":"399","author":"Kisiel","year":"2011","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_11","unstructured":"Alva, S. (2008). Fabrication of all-solid-state Potentiometric ion Sensors and Biosensor Based on Screen-Printed Electrodes and Photocurable Methacrylic-Acrylic Films. [Ph.D. Thesis, Universiti Kebangsaan Malaysia]."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.trac.2015.11.004","article-title":"Rational design of all-solid-state ion-selective electrodes and reference electrodes","volume":"76","author":"Hu","year":"2016","journal-title":"Trends Anal. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"5783","DOI":"10.1021\/ac200627h","article-title":"Disposable planar reference electrode based on carbon nanotubes and polyacrylate membrane","volume":"83","author":"Blondeau","year":"2011","journal-title":"Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2981","DOI":"10.1021\/ac504556s","article-title":"All-solid-state reference electrodes based on colloid-imprinted mesoporous carbon and their application in disposable paper-based potentiometric sensing devices","volume":"87","author":"Hu","year":"2015","journal-title":"Anal. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1016\/j.snb.2004.04.072","article-title":"New concepts of miniaturized reference electrodes in silicon technology for potentiometric sensor systems","volume":"103","author":"Simonis","year":"2004","journal-title":"Sens. Actuators B Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1655","DOI":"10.1039\/b510868c","article-title":"All-solid-state reference electrodes based on conducting polymers","volume":"130","author":"Kisiel","year":"2005","journal-title":"Analyst"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.bioelechem.2006.09.006","article-title":"Plastic reference electrodes and plastic potentiometric cells with dispersion cast poly(3,4-ethylene dioxythiophene) and poly(vinyl chloride) based membranes","volume":"71","author":"Kisiel","year":"2007","journal-title":"Bioelectrochemistry"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1881","DOI":"10.1002\/elan.201100137","article-title":"Ionic liquid-based, liquid-junction-free reference electrode","volume":"23","author":"Cicmil","year":"2011","journal-title":"Electroanalysis"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/j.snb.2005.03.121","article-title":"Ag\/AgCl microelectrodes with improved stability for microfluidics","volume":"114","author":"Polk","year":"2006","journal-title":"Sens. Actuators B Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"479","DOI":"10.22146\/ijc.28859","article-title":"Ag\/AgCl reference electrode based on thin-film of Arabic gum membrane","volume":"18","author":"Alva","year":"2018","journal-title":"Indones. J. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1016\/j.snb.2005.10.018","article-title":"All-solid-state miniaturised planar reference electrodes based on ionic liquids","volume":"115","author":"Dybko","year":"2006","journal-title":"Sens. Actuators B Chem."},{"key":"ref_22","first-page":"1183","article-title":"Pressure driven conducting polymer membranes derived from layer by layer formation and characterization: A review","volume":"11","author":"Yusoff","year":"2016","journal-title":"J. Eng. Sci. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1286","DOI":"10.1002\/1521-4109(200011)12:16<1286::AID-ELAN1286>3.0.CO;2-Q","article-title":"Potential drifts of solid-contacted ion-selective electrodes due to zero-current ion fluxes through the sensor membrane","volume":"12","author":"Fibbioli","year":"2000","journal-title":"Electroanalysis"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2756","DOI":"10.1002\/er.4348","article-title":"Recent advances in additive-enhanced polymer electrolyte membrane properties in fuel cell applications: An overview","volume":"43","author":"Shaari","year":"2019","journal-title":"Int. J. Energy Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1016\/j.rser.2017.05.154","article-title":"Study of the plasticizing effect on polymer and its development in fuel cell application","volume":"79","author":"Wong","year":"2017","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1","DOI":"10.17576\/mjas-2017-2101-01","article-title":"A screen-printed copper ion sensor with photocurable poly(n-butyl acrylate) membrane-based on ionophore o-xylylene bis(N,N-diisobutyl dithiocarbamate)","volume":"21","author":"Kook","year":"2017","journal-title":"Malays. J. Anal. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1016\/j.snb.2013.10.069","article-title":"A reflectometric ion sensor for potassium-based on acrylic microspheres","volume":"191","author":"Yew","year":"2014","journal-title":"Sens Actuators B Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2156","DOI":"10.1002\/elan.201100219","article-title":"The water uptake of plasticized poly(vinyl chloride) solid-contact calcium-selective electrodes","volume":"23","author":"Lindfors","year":"2011","journal-title":"Electroanalysis"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"10","DOI":"10.22441\/ijimeam.2016.1.002","article-title":"Optimization of screen printed reference electrode based on charge balance and poly(butyl acrylate) photocurable membrane","volume":"2","author":"Alva","year":"2016","journal-title":"Int. J. Innov. Mech. Eng. Adv. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1128\/IAI.68.1.165-169.2000","article-title":"Inhibition of human NK cell function by valinomycin, a toxin from Streptomyces griseus in indoor air","volume":"68","author":"Paananen","year":"2000","journal-title":"Infect. Immun."},{"key":"ref_31","unstructured":"Kook, S.Y. (2019). Potentiometric ion Sensor Based on a New Bis-Thiourea Compound in Aluminium Determination. [Ph.D. Thesis, Universiti Kebangsaan Malaysia]."},{"key":"ref_32","unstructured":"Cotruvo, J., Fawell, J.K., Giddings, M., Magara, Y., Aiwerasia, V.F.N., and Ohanian, E. (2009). Potassium in Drinking Water, World Health Organization."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/S0003-2670(01)01195-3","article-title":"Assessing a photocured self-plasticized acrylic membrane recipe for Na+ and K+ ion-selective electrodes","volume":"443","author":"Lee","year":"2001","journal-title":"Anal. Chim. Acta"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2649","DOI":"10.17576\/jsm-2019-4812-06","article-title":"Complexation study of bis-thiourea compound with aluminium ion as ionophore for development of potentiometric ion sensor","volume":"48","author":"Kook","year":"2019","journal-title":"Sains Malays."},{"key":"ref_35","first-page":"379","article-title":"Synthesis, characterization and X-ray structure of N-(4- bromobutanoyl-N\u0384-(2-3-and 4-methyl phenyl)thiourea","volume":"34","author":"Abosadiya","year":"2015","journal-title":"Chin. J. Struct. Chem."},{"key":"ref_36","unstructured":"Alva, S., Lee, Y.H., and Musa, A. (2005, January 5\u20137). A new lithium ion-selective sensors based on self plasticizing acrylic films and disposable screen-printed electrode. Proceedings of the Sensors and the International Conference on New Techniques in Pharmaceutical and Biomedical Research, Kuala Lumpur, Malaysia."},{"key":"ref_37","first-page":"141","article-title":"Screen-printed potassium ion sensor fabricated from photocurable and self-plasticized acrylic film","volume":"17","author":"Alva","year":"2006","journal-title":"J. Phys. Ther. Sci."},{"key":"ref_38","unstructured":"Juliana, J. (2013). Synthesis, Its Application Studies as Ionophore and Anti-Bacterial Test of Some Bis-carbonoylthiourea Derivatives. [Ph.D. Thesis, Universiti Kebangsaan Malaysia]."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1851","DOI":"10.1351\/pac200072101851","article-title":"Potentiometric selectivity coefficients of ion-selective electrodes","volume":"72","author":"Umezawa","year":"2000","journal-title":"Pure Appl. Chem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2527","DOI":"10.1351\/pac199466122527","article-title":"Recommendations for nomenclature of ion-selective electrodes","volume":"66","author":"Buck","year":"1994","journal-title":"Pure Appl. Chem."},{"key":"ref_41","unstructured":"Richard, J.H., Doris, H.C., Joan, D.G., Walter, M., and Malden, C.N. (1989). Recommended Dietary Allowances, National Academy of Sciences. [10th ed.]."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.snb.2014.03.086","article-title":"On the potentiometric response of mercury(II) membrane sensors based on symmetrical thiourea derivatives\u2014Experimental and theoretical approaches","volume":"199","author":"Fayazi","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/S0003-2670(98)00538-8","article-title":"Comparison of different methods for determining the selectivity coefficient using a magnesium-selective electrode","volume":"375","author":"Zhang","year":"1998","journal-title":"Anal. Chim. Acta"},{"key":"ref_44","unstructured":"Ulianas, A. (2007). The Effect of Membrane Composition Changes and Internal Electrolytes on the Response of the Potassium Ion Sensor. [Master\u2019s Thesis, Universiti Kebangsaan Malaysia]."},{"key":"ref_45","first-page":"64","article-title":"A Solid-state Potassium Ion Sensor From Acrylic Membrane Deposited on ISFET Device","volume":"11","author":"Yew","year":"2009","journal-title":"Malaysian J. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1016\/j.snb.2006.09.029","article-title":"Further studies on the role of redox-active monolayer as intermediate phase of solid-state sensors","volume":"123","author":"Plachecka","year":"2007","journal-title":"Sens. Actuators B Chem."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1016\/j.snb.2014.04.081","article-title":"Highly sensitive fluorescence optode for aluminium(III) based on non-plasticized polymer inclusion membrane","volume":"201","author":"Suah","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"161","DOI":"10.21315\/jps2017.28.2.11","article-title":"Development of solid-state reference electrode based on sodium polyanethol sulfonate immobilized on cellulose acetate","volume":"28","author":"Alva","year":"2017","journal-title":"J. Phys. Sci."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1149\/2.007310jes","article-title":"Microfluidic reference electrode with free-diffusion liquid junction","volume":"160","author":"Safari","year":"2013","journal-title":"J. Electrochem. Soc."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1002\/(SICI)1521-4109(200002)12:3<187::AID-ELAN187>3.0.CO;2-Z","article-title":"Taking the plasticizer out of methacrylic-acrylic membranes for K+-selective electrodes","volume":"12","author":"Heng","year":"2000","journal-title":"Electroanalysis"},{"key":"ref_51","unstructured":"Alegret, S., and Merkoci, A. (2007). Electrochemical Sensor Analysis, Elsevier. [1st ed.]."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1016\/j.msec.2015.01.040","article-title":"Design, and construction of new potentiometric sensors for determination of Al3+ ion based on (Z)-2-(2-methyl benzylidene)-1-(2,4-dinitrophenyl)hydrazine","volume":"49","author":"Mizani","year":"2015","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1125","DOI":"10.1002\/1521-4109(200109)13:13<1125::AID-ELAN1125>3.0.CO;2-7","article-title":"Al(III)-selective electrode based on furil as neutral carrier","volume":"13","author":"Mousavi","year":"2001","journal-title":"Electroanalysis"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.molliq.2013.11.014","article-title":"Preparation of a new aluminium (III) selective electrode based on a hydrazone-containing benzimidazole derivative as a neutral carrier","volume":"190","author":"Yan","year":"2014","journal-title":"J. Mol. Liq."},{"key":"ref_55","unstructured":"(2016). New Thiourea Compounds as Ionophores for Potentiometric Sensors of H2PO4\u2212 and Hg2+. [Ph.D. Thesis, Universiti Kebangsaan Malaysia]."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"2394","DOI":"10.1016\/j.jiec.2013.10.019","article-title":"Potentiometric determination of iron in polluted water samples using new modified Fe(III)-screen printed ion-selective electrode","volume":"20","author":"Ali","year":"2014","journal-title":"J. Ind. Eng. Chem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"204","DOI":"10.5740\/jaoacint.11-182","article-title":"Potentiometric determination of trace amounts of aluminium utilizing polyvinyl chloride membrane and coated platinum sensors based on E-N\u2019-(2-hydroxy-3-methoxybenzylidene)benzohydrazide","volume":"96","author":"Tajik","year":"2013","journal-title":"J. AOAC Int."},{"key":"ref_58","unstructured":"Deviant, S. (2011). The Practically Cheating Statistics Handbook, Createspace Independent Publishing Platform. [2nd ed.]."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1041","DOI":"10.1038\/nmeth.2698","article-title":"Points of significance: Significance, P values and t-tests","volume":"10","author":"Krzywinski","year":"2013","journal-title":"Nat. Methods"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1016\/j.snb.2014.07.023","article-title":"Optimization of polymer inclusion membranes (PIMs) preparation for immobilization of chrome azurol S for optical sensing of aluminium (III)","volume":"203","author":"Ngarisan","year":"2014","journal-title":"Sens. Actuators B. Chem."},{"key":"ref_61","first-page":"2960","article-title":"The fabrication of potentiometric membrane sensors and their applications","volume":"6","author":"Faridbod","year":"2007","journal-title":"Arf. J. Biotechnol."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/S1452-3981(23)15264-3","article-title":"An imidazol based novel potentiometric PVC membrane sensor for aluminium (III) determination","volume":"5","author":"Bera","year":"2010","journal-title":"Int. J. Electrochem. Sci."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1090","DOI":"10.1134\/S1061934808110130","article-title":"Aluminium(III)-selective electrode based on a newly synthesized glyoxal-bis-thiosemicarbazone schiff base","volume":"63","author":"Li","year":"2008","journal-title":"J. Anal. Chem."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/23\/6898\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:40:51Z","timestamp":1760179251000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/23\/6898"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,3]]},"references-count":63,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["s20236898"],"URL":"https:\/\/doi.org\/10.3390\/s20236898","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,3]]}}}