{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T11:01:49Z","timestamp":1789642909349,"version":"4.0.0"},"reference-count":66,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"publisher","award":["24-73-10058"],"award-info":[{"award-number":["24-73-10058"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]},{"award":["24-73-10058"],"award-info":[{"award-number":["24-73-10058"]}],"id":[{"id":"https:\/\/ror.org\/03y2gwe85","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>The development of highly sensitive and stable gas sensors at room temperature is crucial for environmental and industrial monitoring. This study reports the synthesis and characterization of novel ammonia sensors based on covalently functionalized single-walled carbon nanotubes (SWCNT-NH2) with tetra- and octa-chlorinated zinc phthalocyanines (ZnPcCl4 and ZnPcCl8). These covalent hybrids were prepared by replacing peripheral halogen atoms with amino groups on the surface of the nanotubes, which significantly increased the loading of the macrocycles compared to non-covalently functionalized analogs, reduced nanotube aggregation, and improved electrical conductivity. The sensors exhibited fully reversible responses to NH3 at room temperature. Among the tested materials, the covalent hybrid of SWCNT-NH2\/ZnPcCl8 demonstrated superior performance. It achieved a limit of detection of 0.7 ppm and rapid response and recovery times (60 and 65 s, respectively, at 10 ppm). The sensor\u2019s response was over 10 times higher than that of its tetrasubstituted ZnPcCl4 counterpart and more than 100 times higher than for non-covalent hybrids. The sensor also showed excellent long-term stability (greater than 1 month) and high selectivity for CO2 and volatile organic compounds. Quantum chemical calculations revealed that the increased sensitivity of the octa-chlorinated derivative did not result from stronger analyte binding but rather from the strong electron-withdrawing nature of chlorine substituents, which create an electron-depleted carbon framework. This causes a constant charge transfer from adsorbed NH3, inducing a proportionally larger change in majority carrier concentration.<\/jats:p>","DOI":"10.3390\/ijms27188275","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T09:59:03Z","timestamp":1789639143000},"page":"8275","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Modification of Single-Walled Carbon Nanotubes with Halogen-Substituted Metal Phthalocyanines for Chemiresistive Ammonia Detection"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9497-8899","authenticated-orcid":false,"given":"Darya","family":"Klyamer","sequence":"first","affiliation":[{"name":"Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5843-0455","authenticated-orcid":false,"given":"Pavel","family":"Krasnov","sequence":"additional","affiliation":[{"name":"International Research Center of Spectroscopy and Quantum Chemistry, Siberian Federal University, 26 Kirensky St., Krasnoyarsk 660074, Russia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1693-2323","authenticated-orcid":false,"given":"Victoria","family":"Volchek","sequence":"additional","affiliation":[{"name":"Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1555-2719","authenticated-orcid":false,"given":"Evgeny","family":"Maksimovskiy","sequence":"additional","affiliation":[{"name":"Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4833-4582","authenticated-orcid":false,"given":"Anastasiya","family":"Fedorenko","sequence":"additional","affiliation":[{"name":"Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2084-2363","authenticated-orcid":false,"given":"Victoria","family":"Ivanova","sequence":"additional","affiliation":[{"name":"Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4001-8371","authenticated-orcid":false,"given":"Tamara","family":"Basova","sequence":"additional","affiliation":[{"name":"Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Tang, J., Li, R., Mahmood, S., Li, J., and Yao, S. (2025). Carbon Nanotube-Based Chemical Sensors: Sensing Mechanism, Functionalization and Applications. Chemosensors, 13.","DOI":"10.3390\/chemosensors13100367"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Parvin, N., Joo, S.W., Jung, J.H., and Mandal, T.K. (2025). Unlocking the Future: Carbon Nanotubes as Pioneers in Sensing Technologies. Chemosensors, 13.","DOI":"10.3390\/chemosensors13070225"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100064","DOI":"10.1016\/j.pscia.2025.100064","article-title":"Single-walled carbon nanotubes sensors: Preparation and bio-application advances","volume":"3","author":"Chen","year":"2025","journal-title":"Pharm. Sci. Adv."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1038\/s43586-023-00255-6","article-title":"Chemiresistive sensing with functionalized carbon nanotubes","volume":"3","author":"Luo","year":"2023","journal-title":"Nat. Rev. Methods Primers"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"100841","DOI":"10.1016\/j.apsadv.2025.100841","article-title":"Surface engineering of carbon nanotube films via pyrene grafting for high-performance flexible supercapacitors","volume":"29","author":"Jeong","year":"2025","journal-title":"Appl. Surf. Sci. Adv."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"144276","DOI":"10.1016\/j.apsusc.2019.144276","article-title":"3D, covalent and noncovalent hybrid materials based on 3-phenylcoumarin derivatives and single walled carbon nanotubes as gas sensing layers","volume":"504","author":"Polyakov","year":"2020","journal-title":"Appl. Surf. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"126812","DOI":"10.1016\/j.molliq.2024.126812","article-title":"Intermolecular interactions of BODIPY and SWCNTs in solutions, a new approach to obtaining in a supercritical CO2 the PMMA\/BODIPY\/SWCNTs composites","volume":"419","author":"Sherudillo","year":"2025","journal-title":"J. Mol. Liq."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"15349","DOI":"10.1002\/chem.201501817","article-title":"Azido-Substituted BODIPY Dyes for the Production of Fluorescent Carbon Nanotubes","volume":"21","author":"Fedeli","year":"2015","journal-title":"Chem.\u2013Eur. J."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Rebelo, S.L.H., Laia, C.A.T., Szefczyk, M., Guedes, A., Silva, A.M.G., and Freire, C. (2023). Hybrid Zn-\u03b2-Aminoporphyrin\u2013Carbon Nanotubes: Pyrrolidine and Direct Covalent Linkage Recognition, and Multiple-Photo Response. Molecules, 28.","DOI":"10.3390\/molecules28217438"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1080\/10601325.2023.2210172","article-title":"Porphyrin linked carbon nanostructures in polymeric nanocomposite\u2014State-of-the-art and headways","volume":"60","author":"Kausar","year":"2023","journal-title":"J. Macromol. Sci. Part A"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"115389","DOI":"10.1016\/j.jelechem.2021.115389","article-title":"Development and characterization of iron (III) phthalocyanine modified carbon nanotube paste electrodes and application for determination of fluometuron herbicide as an electrochemical sensor","volume":"895","author":"Demir","year":"2021","journal-title":"J. Electroanal. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"046515","DOI":"10.1149\/1945-7111\/ab7982","article-title":"Selective Voltammetric Determination of Nitrite Using Cobalt Phthalocyanine Modified on Multiwalled Carbon Nanotubes","volume":"167","author":"Lu","year":"2020","journal-title":"J. Electrochem. Soc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e7302","DOI":"10.1002\/aoc.7302","article-title":"Novel nitrogen-rich anchored nickel (II) phthalocyanine with composite of multiwalled carbon nanotubes on modified glassy carbon electrode: Sensitive and selective electrocatalytic activity of nitrite","volume":"38","author":"Mounesh","year":"2024","journal-title":"Appl. Organomet. Chem."},{"key":"ref_14","first-page":"1","article-title":"Versatile Surface Chemistry of Carbon-Based Nanoplatforms by Covalent Bonding, Non-Covalent Linking, Crosslinking, and Self-Assembling","volume":"5","author":"Bracamonte","year":"2023","journal-title":"Recent Prog. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Ganjoo, R., Sharma, S., and Kumar, A. (2023). Activation of Carbon Allotropes Through Covalent and Noncovalent Functionalization. Carbon Allotropes and Composites, John Wiley & Sons, Ltd.","DOI":"10.1002\/9781394167913.ch3"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1039\/b507451g","article-title":"Noncovalent interactions of molecules with single walled carbon nanotubes","volume":"35","author":"Britz","year":"2006","journal-title":"Chem. Soc. Rev."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Ferreira, F.V., Cividanes, L.D.S., Brito, F.S., de Menezes, B.R.C., Franceschi, W., Simonetti, E.A.N., and Thim, G.P. (2016). Functionalization of Carbon Nanotube and Applications. Functionalizing Graphene and Carbon Nanotubes, Springer International Publishing.","DOI":"10.1007\/978-3-319-35110-0_2"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"11151","DOI":"10.1021\/jp046274g","article-title":"Covalent Functionalization of Single-Walled Carbon Nanotubes for Materials Applications","volume":"108","author":"Dyke","year":"2004","journal-title":"J. Phys. Chem. A"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Speranza, G. (2019). The Role of Functionalization in the Applications of Carbon Materials: An Overview. C\u2014J. Carbon Res., 5.","DOI":"10.3390\/c5040084"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2606","DOI":"10.1016\/j.electacta.2009.12.051","article-title":"Electrocatalytic oxidation of amitrole and diuron on iron(II) tetraaminophthalocyanine-single walled carbon nanotube dendrimer","volume":"55","author":"Mugadza","year":"2010","journal-title":"Electrochim. Acta"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6049","DOI":"10.1016\/j.electacta.2010.05.065","article-title":"Synthesis, characterization and the electrocatalytic behaviour of nickel (II) tetraamino-phthalocyanine chemically linked to single walled carbon nanotubes","volume":"55","author":"Mugadza","year":"2010","journal-title":"Electrochim. Acta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"6347","DOI":"10.1016\/j.electacta.2009.05.074","article-title":"Synthesis and characterization of electrocatalytic conjugates of tetraamino cobalt (II) phthalocyanine and single wall carbon nanotubes","volume":"54","author":"Mugadza","year":"2009","journal-title":"Electrochim. Acta"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"129198","DOI":"10.1016\/j.snb.2020.129198","article-title":"Novel SWCNT-hybrid nanomaterial functionalized with subphthalocyanine substituted asymmetrical zinc (II) phthalocyanine conjugate: Design, synthesis, characterization and sensor properties for pesticides","volume":"329","year":"2021","journal-title":"Sens. Actuators B Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"117710","DOI":"10.1016\/j.memsci.2019.117710","article-title":"Surface modification of functionalized multiwalled carbon nanotubes containing mixed matrix membrane using click chemistry","volume":"596","author":"Nikita","year":"2020","journal-title":"J. Membr. Sci."},{"key":"ref_25","first-page":"409","article-title":"Fluorinated phthalocyanines as molecular semiconductor thin films","volume":"205","author":"Brinkmann","year":"2008","journal-title":"Phys. Status Solidi Appl. Mater. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3019","DOI":"10.1002\/cjce.24843","article-title":"From P-type to N-type: Peripheral fluorination of axially substituted silicon phthalocyanines enables fine tuning of charge transport","volume":"101","author":"Vebber","year":"2023","journal-title":"Can. J. Chem. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Klyamer, D., Sukhikh, A., Gromilov, S., Krasnov, P., and Basova, T. (2018). Fluorinated metal phthalocyanines: Interplay between fluorination degree, films orientation, and ammonia sensing properties. Sensors, 18.","DOI":"10.3390\/s18072141"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.apsusc.2017.08.040","article-title":"Non-covalently anchored multi-walled carbon nanotubes with hexa-decafluorinated zinc phthalocyanine as ppb level chemiresistive chlorine sensor","volume":"427","author":"Sharma","year":"2018","journal-title":"Appl. Surf. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"32719","DOI":"10.1039\/C8RA05529G","article-title":"Tailoring of the chlorine sensing properties of substituted metal phthalocyanines non-covalently anchored on single-walled carbon nanotubes","volume":"8","author":"Sharma","year":"2018","journal-title":"RSC Adv."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.snb.2017.08.013","article-title":"Reversible and fast responding ppb level Cl2 sensor based on noncovalent modified carbon nanotubes with Hexadecafluorinated copper phthalocyanine","volume":"255","author":"Sharma","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_31","first-page":"41","article-title":"Effects of Chlorine Substitution and Nanotube Oxidation on Ammonia Detection in Zinc Phthalocyanine-SWCNT Hybrid Sensors: Experimental Studies and Quantum Chemical Calculations","volume":"19","author":"Ivanova","year":"2026","journal-title":"Macroheterocycles"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"216404","DOI":"10.1016\/j.ccr.2024.216404","article-title":"New vitality of covalent organic frameworks endued by phthalocyanine: Yesterday, today, and tomorrow","volume":"527","author":"Pan","year":"2025","journal-title":"Coord. Chem. Rev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"21328","DOI":"10.1021\/jacs.2c09482","article-title":"Piperazine-Linked Metalphthalocyanine Frameworks for Highly Efficient Visible-Light-Driven H2O2 Photosynthesis","volume":"144","author":"Zhi","year":"2022","journal-title":"J. Am. Chem. Soc."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"11176","DOI":"10.1021\/jp4018458","article-title":"Study of the anchoring process of tethered unsymmetrical Zn-phthalocyanines on TiO2 nanostructured thin films","volume":"117","author":"Pellegrino","year":"2013","journal-title":"J. Phys. Chem. C"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"6902","DOI":"10.1038\/s41598-020-63935-3","article-title":"From graphene oxide towards aminated graphene: Facile synthesis, its structure and electronic properties","volume":"10","author":"Rabchinskii","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"21114","DOI":"10.1038\/s41598-022-25222-1","article-title":"Design of double functionalized carbon nanotube for amphotericin B and genetic material delivery","volume":"12","author":"Yazdani","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Karstens, R., Glaser, M., Belser, A., Balle, D., Polek, M., Ovsyannikov, R., Giangrisostomi, E., Chass\u00e9, T., and Peisert, H. (2019). FePc and FePcF16 on rutile TiO2(110) and (100): Influence of the substrate preparation on the interaction strength. Molecules, 24.","DOI":"10.3390\/molecules24244579"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"9616","DOI":"10.1021\/ja910169v","article-title":"Tuning the acid\/base properties of nanocarbons by functionalization via amination","volume":"132","author":"Arrigo","year":"2010","journal-title":"J. Am. Chem. Soc."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"799","DOI":"10.1063\/1.1681153","article-title":"X-ray photoelectron spectroscopy of tetraphenylporphin and phthalocyanine","volume":"60","author":"Niwa","year":"1974","journal-title":"J. Chem. Phys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"9374","DOI":"10.1039\/C4RA15306E","article-title":"Interfacial peroxidase-like catalytic activity of surface-immobilized cobalt phthalocyanine on multiwall carbon nanotubes","volume":"5","author":"Li","year":"2015","journal-title":"RSC Adv."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"13420","DOI":"10.1038\/s41598-022-16931-8","article-title":"Understanding structure\u2013properties relationships of porphyrin linked to graphene oxide through \u03c0\u2013\u03c0-stacking or covalent amide bonds","volume":"12","author":"Gacka","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.synthmet.2017.02.024","article-title":"Effect of covalent and non-covalent linking of zinc(II) phthalocyanine functionalised carbon nanomaterials on the sensor response to ammonia","volume":"227","author":"Polyakov","year":"2017","journal-title":"Synth. Met."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.snb.2012.11.014","article-title":"Gas sensors using carbon nanomaterials: A review","volume":"179","author":"Llobet","year":"2013","journal-title":"Sens. Actuators B Chem."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"79729","DOI":"10.1039\/C5RA13976G","article-title":"Copper(II) phthalocyanine supported on a three-dimensional nitrogen-doped graphene\/PEDOT-PSS nanocomposite as a highly selective and sensitive sensor for ammonia detection at room temperature","volume":"5","author":"Dehsari","year":"2015","journal-title":"RSC Adv."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1016\/j.carbon.2014.08.065","article-title":"Enhanced NH3-sensing behavior of 2,9,16, 23-tetrakis(2,2,3,3-tetrafluoropropoxy) metal(II) phthalocyanine\/multi-walled carbon nanotube hybrids: An investigation of the effects of central metals","volume":"80","author":"Liang","year":"2014","journal-title":"Carbon"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.snb.2017.02.083","article-title":"Stably dispersed metallophthalocyanine noncovalently bonded to multiwalled carbon nanotubes for ammonia sensing at room temperature","volume":"246","author":"Kang","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1016\/j.snb.2012.04.084","article-title":"Lead phthalocyanine modified carbon nanotubes with enhanced NH3 sensing performance","volume":"171\u2013172","author":"Wang","year":"2012","journal-title":"Sens. Actuators B Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"139753","DOI":"10.1016\/j.snb.2026.139753","article-title":"Wine discrimination through an electronic nose based on SWCNTs functionalized with Zn phthalocyanine","volume":"458","author":"Freddi","year":"2026","journal-title":"Sens. Actuators B Chem."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"114534","DOI":"10.1016\/j.microc.2025.114534","article-title":"Tetra-\u03b2-carboxylate cobalt phthalocyanine tetrasodium salt bridged Polypyrrole coated carbon nanotubes for improved ammonia sensing performance at room temperature","volume":"216","author":"Gai","year":"2025","journal-title":"Microchem. J."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"134733","DOI":"10.1016\/j.snb.2023.134733","article-title":"3D hybrid materials based on zinc and cobalt phthalocyanine derivatives bearing terminal ethynyl substituents as active layers for chemiresistive gas sensors","volume":"398","author":"Ivanova","year":"2024","journal-title":"Sens. Actuators B Chem."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"8279","DOI":"10.1039\/D5NJ00507H","article-title":"Effect of the number and position of substituents on the orientation and sensor response of triethylene glycol-substituted silicon phthalocyanine films to ammonia","volume":"49","author":"Ivanova","year":"2025","journal-title":"New J. Chem."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1290","DOI":"10.1021\/cm048357f","article-title":"Amino-Functionalized Carbon Nanotubes for Binding to Polymers and Biological Systems","volume":"17","author":"Ramanathan","year":"2005","journal-title":"Chem. Mater."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"4987","DOI":"10.1016\/j.carbon.2012.06.007","article-title":"Spectroscopic study of double-walled carbon nanotube functionalization for preparation of carbon nanotube \/ epoxy composites","volume":"50","author":"Leon","year":"2012","journal-title":"Carbon"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"3334","DOI":"10.1039\/b504282h","article-title":"Covalent amino-functionalisation of single-wall carbon nanotubes","volume":"15","author":"Gromov","year":"2005","journal-title":"J. Mater. Chem."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"2397","DOI":"10.1002\/jcc.21821","article-title":"On the Applicability of Cluster Models to Study the Chemical Reactivity of Carbon Nanotubes","volume":"32","author":"Denis","year":"2011","journal-title":"J. Comput. Chem."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"84707","DOI":"10.1063\/1.2839294","article-title":"Energy gaps, electronic structures, and x-ray spectroscopies of finite semiconductor single-walled carbon nanotubes","volume":"128","author":"Gao","year":"2008","journal-title":"J. Chem. Phys."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"025711","DOI":"10.1088\/0957-4484\/19\/02\/025711","article-title":"Ab initio calculations of electron affinity and ionization potential of carbon nanotubes","volume":"19","author":"Buonocore","year":"2008","journal-title":"Nanotechnology"},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Kamdina, T., Klyamer, D., Sukhikh, A., Popovetskiy, P., Krasnov, P., and Basova, T. (2026). Octachlorinated Metal Phthalocyanines (M = Co, Zn, VO): Crystal Structures, Thin-Film Properties, and Chemiresistive Sensing of Ammonia and Hydrogen Sulfide. Sensors, 26.","DOI":"10.3390\/s26010008"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"7260","DOI":"10.1103\/PhysRevB.58.7260","article-title":"Self-consistent-charge density-functional tight-binding method for simulations of complex materials properties","volume":"58","author":"Elstner","year":"1998","journal-title":"Phys. Rev. B"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"124101","DOI":"10.1063\/1.5143190","article-title":"DFTB+, a software package for efficient approximate density functional theory based atomistic simulations","volume":"152","author":"Hourahine","year":"2020","journal-title":"J. Chem. Phys."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1062","DOI":"10.1021\/jp506557r","article-title":"Parametrization of DFTB3\/3OB for Magnesium and Zinc for Chemical and Biological Applications","volume":"119","author":"Lu","year":"2015","journal-title":"J. Phys. Chem. B"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1021\/ct300849w","article-title":"Parametrization and Benchmark of DFTB3 for Organic Molecules","volume":"9","author":"Gaus","year":"2013","journal-title":"J. Chem. Theory Comput."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1456","DOI":"10.1002\/jcc.21759","article-title":"Effect of the damping function in dispersion corrected density functional theory","volume":"32","author":"Grimme","year":"2011","journal-title":"J. Comput. Chem."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"154104","DOI":"10.1063\/1.3382344","article-title":"A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu","volume":"132","author":"Grimme","year":"2010","journal-title":"J. Chem. Phys."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1833","DOI":"10.1063\/1.1740588","article-title":"Electronic population analysis on LCAO-MO molecular wave functions. I","volume":"23","author":"Mulliken","year":"1955","journal-title":"J. Chem. Phys."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"1841","DOI":"10.1063\/1.1740589","article-title":"Electronic population analysis on LCAO-MO molecular wave functions. II. Overlap populations, bond orders, and covalent bond energies","volume":"23","author":"Mulliken","year":"1955","journal-title":"J. Chem. Phys."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/18\/8275\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T10:02:16Z","timestamp":1789639336000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/18\/8275"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,17]]},"references-count":66,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["ijms27188275"],"URL":"https:\/\/doi.org\/10.3390\/ijms27188275","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,17]]}}}