Determination of non-traditional intrinsic fluorescence (NTIF) emission sites in 1-(4-carbomethoxypyrrolidone)-PAMAM dendrimers using CNDP-based quenching studies
| العنوان: | Determination of non-traditional intrinsic fluorescence (NTIF) emission sites in 1-(4-carbomethoxypyrrolidone)-PAMAM dendrimers using CNDP-based quenching studies |
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| المؤلفون: | David M. Hedstrand, Kayla A.-M. Johnson, Barbara Klajnert-Maculewicz, Donald A. Tomalia, Malgorzata Konopka, Anna Janaszewska |
| المصدر: | Journal of Nanoparticle Research. 20 |
| بيانات النشر: | Springer Science and Business Media LLC, 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | Quenching (fluorescence), Photoluminescence, Pamam dendrimers, Materials science, Tertiary amine, Amidoamine, Auto fluorescence, Bioengineering, 02 engineering and technology, General Chemistry, Intrinsic fluorescence, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Photochemistry, 01 natural sciences, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Modeling and Simulation, Dendrimer, General Materials Science, 0210 nano-technology |
| الوصف: | A unique photoluminescent phenomenon producing inexplicable, blue emissions [λEx = 365 nm; λEm = 460 nm] in the absence of traditional aromatic fluorophores has been observed in a variety of surface functionalized poly(amidoamine) (PAMAM) dendrimers over the past two decades. This emission phenomenon, referred to as non-traditional intrinsic fluorescence (NTIF), originates from the intra-molecular clustering of electron-rich sub-fluorophores (i.e., tertiary amines and/or amido groups) residing in the interior of all PAMAM dendrimers. The intra-molecular clustering of these interior sub-fluorophores is hypothesized to account for the modest but reproducible, blue emissions observed for a variety of dendrimer surface moieties (i.e., –OH, –CO2H, and –NH2). Unexpectedly, a simple, one-step conversion of amine-terminated PAMAM dendrimers to 1-(4-carbomethyoxy) pyrrolidone-terminated dendrimers (4-CMP) was found to produce a 50-fold increase in blue NTIF emission compared to other surface moieties. In an effort to understand this new enhanced emission property, critical nanoscale design parameter (CNDP)-directed quenching experiments were devised to probe the increased NTIF emissions. Was it originating from the interior sub-fluorophoric tertiary amine/amido moieties or from the surface-attached, sub-fluorophoric pyrrolidone amido groups or both? Four generations of 4-CMP PAMAM dendrimers were examined. Two classical quenchers, namely, potassium iodide and acrylamide were selected to probe surface versus interior domains, respectively, as a function of predictable CNDPs associated with generation levels. With increasing dendrimer generation, quencher penetration into the dendrimer interior is impeded due to CNDP-directed generational congestion. Stern-Volmer plots for each quencher, as a function of generation, exhibited appropriate linear or non-linear correlations that corroborated behavior expected for two distinct region-specific emission sites. |
| تدمد: | 1572-896X 1388-0764 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::e388334acfc3d014d307585e9efda90d https://doi.org/10.1007/s11051-018-4310-7 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........e388334acfc3d014d307585e9efda90d |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Springer Verlag. | تدمد: | 1572896X 13880764 |
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