Influence of Surface Silanization on the Physicochemical Stability of Silver Nanocoatings: A Large Length Scale Assessment

• Published in: Journal of physical chemistry. C Vol. 121; no. 21; pp. 11300 - 11311
• Main Authors: Noronha, Victor T, Sousa, Francisco A, Souza Filho, Antonio G, Silva, Cristiane A, Cunha, Francisco A, Koo, Hyun, Fechine, Pierre B. A, Paula, Amauri J
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01-06-2017
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.7b00706

We synthesized sub-100 nm “biogenic” protein-capped silver nanoparticles (bio-AgNPs) from a yeast extract (Rhodotorula glutinis) and assessed the chemical stability of their coatings formed on various silane-modified substrates up to the millimeter length scale. Large-field (LF) X-ray imaging was used for scanning AgNPs-coated substrates (5 × 5 mm) after they were immersed in physiological PBS for hours. Striking differences were found in the amount and the structural organization of bio-AgNPs in the coatings depending on the type of surface silanization. The relative amount of bio-AgNPs in the coatings increases due to the assembly of enlarged (8–30 μm2 in area) and chemically stable agglomerates of bio-AgNPs formed on a multilayered aminosilane film (average 230 nm thickness), which was generated with the use of 3-aminopropyl­trimethoxysilane (APTMS). In contrast, substantially less bio-AgNPs was found on the hydrophobic silane film generated with the use of trimethoxy­phenylsilane (TMPS) and on the films generated with 3-trihydroxysilyl­propyl­methyl­phosphonate (THSMP) and 3-mercapto­propyl­trimethoxysilane (MPTMS). As silver nanocoatings formed on APTMS films have a remarkable stability against nanoparticle lixiviation/detachment, this architecture has a great potential in several biotechnological applications that require resistant coatings of nanoparticle for acting in physiological medium/buffers and biological fluids that contain high ionic strength, especially for catalysis and sensors and as antimicrobial surfaces.