{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T14:40:21Z","timestamp":1790347221246,"version":"4.1.0"},"reference-count":51,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2025,7,26]],"date-time":"2025-07-26T00:00:00Z","timestamp":1753488000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Experimental and theoretical studies were applied to investigate the adsorption properties of testagen (KEDG) peptide on copper surfaces in sodium chloride solution and, implicitly, its inhibition efficiency (IE) on metal corrosion. The tetrapeptide synthesized from the amino acids lysine (Lys), glutamic acid (Glu), aspartic acid (Asp), and glycine (Gly), named as H-Lys-Glu-Asp-Gly-OH, achieved an inhibition efficiency of around 86% calculated from electrochemical measurements, making KEDG a promising new copper corrosion inhibitor. The experimental data were best fitted to the Freundlich adsorption isotherm. The standard free energy of adsorption (\u0394Gadso) reached the value of \u221230.86 kJ mol\u22121, which revealed a mixed action mechanism of tetrapeptide, namely, chemical and physical spontaneous adsorption. The copper surface characterization was performed using optical microscopy and SEM\/EDS analysis. In the KEDG presence, post-corrosion, SEM images showed a network surface morphology including microdeposits with an acicular appearance, and EDS analysis highlighted an upper surface layer consisting of KEDG, sodium chloride, and copper corrosion compounds. The computational study based on DFT and Monte Carlo simulation confirmed the experimental results and concluded that the spontaneous adsorption equilibrium establishment was the consequence of the contribution of noncovalent (electrostatic, van der Waals) interactions and covalent bonds.<\/jats:p>","DOI":"10.3390\/molecules30153141","type":"journal-article","created":{"date-parts":[[2025,7,28]],"date-time":"2025-07-28T08:51:33Z","timestamp":1753692693000},"page":"3141","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Inhibitory Effect and Adsorption Properties of Testagen Peptide on Copper Surfaces in Saline Environments: An Experimental and Computational Study"],"prefix":"10.3390","volume":"30","author":[{"given":"Aurelian","family":"Dobri\u0163escu","sequence":"first","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adriana","family":"Samide","sequence":"additional","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicoleta","family":"Cioater\u0103","sequence":"additional","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oana Camelia","family":"Mic","sequence":"additional","affiliation":[{"name":"Doctoral School of Chemical Engineering and Biotechnology, National University of Science and Technology POLITEHNICA Bucharest, 1\u20137 Gheorghe Polizu St., Sector 1, 011061 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C\u0103t\u0103lina","family":"Ionescu","sequence":"additional","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Irina","family":"D\u0103buleanu","sequence":"additional","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristian","family":"Tigae","sequence":"additional","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cezar Ionu\u0163","family":"Sp\u00eenu","sequence":"additional","affiliation":[{"name":"Faculty of Sciences 107i Calea Bucuresti, Department of Chemistry, University of Craiova, 200478 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bogdan","family":"Oprea","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, University of Medicine and Pharmacy, Petru Rares, 2, 200349 Craiova, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1016\/j.ejpe.2018.04.004","article-title":"The use of amino acids as corrosion inhibitors for metals: A review","volume":"27","author":"Hamadi","year":"2018","journal-title":"Egypt. 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