scholarly journals Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2592 ◽  
Author(s):  
Deng ◽  
Yu

Fluorescence titration of methylene blue, rhodamine B and rhodamine 6G (R6G) by silver nanoparticle (AgNP) all resulted in an initial steep quenching curve followed with a sharp turn and a much flatter quenching curve. At the turn, there are about 200,000 dye molecules per a single AgNP, signifying self-assembly of approximately 36-layers of dye molecules on the surface of the AgNP to form a micelle-like structure. These fluorescence-quenching curves fit to a mathematical model with an exponential term due to molecular self-assembly on AgNP surface, or we termed it “self-assembly shielding effect”, and a Stern-Volmer term (nanoparticle surface enhanced quenching). Such a “super-quenching” by AgNP can only be attributed to “pre-concentration” of the dye molecules on the nanoparticle surface that yields the formation of micelle-like self-assembly, resulting in great fluorescence quenching. Overall, the fluorescence quenching titration reveals three different types of interactions of dye molecules on AgNP surface: 1) self-assembly (methylene blue, rhodamine B and R6G), 2) absorption/tight interaction (tryptamine and fluorescein), and 3) loose interaction (eosin Y). We attribute the formation of micelle-like self-assembly of these three dye molecules on AgNP to their positive charge, possession of nitrogen atoms, and with relatively large and flat aromatic moieties.

2017 ◽  
Vol 41 (9) ◽  
pp. 3661-3666 ◽  
Author(s):  
Liu Yang ◽  
Xiao Li ◽  
Chun-Yi Sun ◽  
Han Wu ◽  
Chun-Gang Wang ◽  
...  

A pillared-layer metal–organic framework can be used to separate rhodamine B (RB) and methylene blue (MB) dye molecules in a short amount of time.


2019 ◽  
Vol 48 (12) ◽  
pp. 1504-1506
Author(s):  
Hua Deng ◽  
Paresh C Ray ◽  
William E. Ghann ◽  
Jamal Uddin ◽  
Alexander Samokhvalov ◽  
...  

2017 ◽  
Vol 13 (6) ◽  
Author(s):  
Linshan Wang ◽  
Cholhwan Kim ◽  
Xinyue Zhang ◽  
Carlos Fernandez ◽  
Ting Sun ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shan-Bao Qiao

Abstract A new Cu(II) complex, [Cu2(1,3-BMIB)(OBA)2] n (1) (1,3-BMIB = 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene, H2OBA = 4,4′-oxybis(benzoic acid)) was hydrothermally synthesized and has been structurally characterized. Complex 1 possesses a 3D 2-fold interpenetrating framework based on [Cu(OBA)] n layers with a Schläfli symbol {412.63}. Complex 1 displays excellent photocatalytic properties in the degradation of methylene blue (MB) and rhodamine B (RhB).


2021 ◽  
Vol 11 (6) ◽  
pp. 2472
Author(s):  
Ilaria Fratoddi ◽  
Chiara Battocchio ◽  
Giovanna Iucci ◽  
Daniele Catone ◽  
Antonella Cartoni ◽  
...  

This paper presents the synthesis of silver nanoparticles (AgNPs) functionalized with fluorescent molecules, in particular with xanthene-based dyes, i.e., fluorescein isothiocyanate (FITC, λmax = 485 nm) and rhodamine B isothiocyanate (RITC, λmax = 555 nm). An in-depth characterization of the particle–dye systems, i.e., AgNPs–RITC and AgNPs–FITC, is presented to evaluate their chemical structure and optical properties due to the interaction between their plasmonic and absorption properties. UV–Vis spectroscopy and the dynamic light scattering (DLS) measurements confirmed the nanosize of the AgNPs–RITC and AgNPs–FITC. Synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS) was used to study the chemical surface functionalization by structural characterization, confirming/examining the isothiocyanate–metal interaction. For AgNPs–RITC, in which the plasmonic and fluorescence peak are not superimposed, the transient dynamics of the dye fluorescence were also studied. Transient absorption measurements showed that by exciting the AgNPs–RITC sample at a wavelength corresponding to the AgNP plasmon resonance, it was possible to preferentially excite the RITC dye molecules attached to the surface of the NPs with respect to the free dye molecules in the solution. These results demonstrate how, by combining plasmonics and fluorescence, these AgNPs can be used as promising systems in biosensing and imaging applications.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3598
Author(s):  
Nirmal K. Shee ◽  
Hee-Joon Kim

A series of porphyrin triads (1–6), based on the reaction of trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP) with six different phenoxy Zn(II)-porphyrins (ZnLn), was synthesized. The cooperative metal–ligand coordination of 3-pyridyl nitrogens in the SnP with the phenoxy Zn(II)-porphyrins, followed by the self-assembly process, leads to the formation of nanostructures. The red-shifts and remarkable broadening of the absorption bands in the UV–vis spectra for the triads in CHCl3 indicate that nanoaggregates may be produced in the self-assembly process of these triads. The emission intensities of the triads were also significantly reduced due to the aggregation. Microscopic analyses of the nanostructures of the triads reveal differences due to the different substituents on the axial Zn(II)-porphyrin moieties. All these nanomaterials exhibited efficient photocatalytic performances in the degradation of rhodamine B (RhB) dye under visible light irradiation, and the degradation efficiencies of RhB in aqueous solution were observed to be 72~95% within 4 h. In addition, the efficiency of the catalyst was not impaired, showing excellent recyclability even after being applied for the degradation of RhB in up to five cycles.


2021 ◽  
Vol 4 (2) ◽  
pp. 1149-1161 ◽  
Author(s):  
Ana Rovisco ◽  
Rita Branquinho ◽  
Jonas Deuermeier ◽  
Tomás Freire ◽  
Elvira Fortunato ◽  
...  

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