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Laser-induced transformation of supramolecular complexes: approach to controlled formation of hybrid multi-yolk-shell Au-Ag@a-C:H nanostructures.

Manshina AA, Grachova EV, Povolotskiy AV, Povolotckaia AV, Petrov YV, Koshevoy IO, Makarova AA, Vyalikh DV, Tunik SP - Sci Rep (2015)

Bottom Line: It has been demonstrated that variation of the experimental parameters such as type of the organometallic precursor, solvent, deposition geometry and duration of laser irradiation allows directed control of nanoparticles' dimension and morphology.The mechanism of Au-Ag@a-C:H nanoparticles formation is suggested: the photo-excitation of the precursor molecule through metal-to-ligand charge transfer followed by rupture of metallophilic bonds, transformation of the cluster core including red-ox intramolecular reaction and aggregation of heterometallic species that results in the hybrid metal/carbon nanoparticles with multi-yolk-shell architecture formation.It has been found that the nanoparticles obtained can be efficiently used for the Surface-Enhanced Raman Spectroscopy label-free detection of human serum albumin in low concentration solution.

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemistry, St. Petersburg State University, Universitetskii pr. 26, St. Petersburg, 198504, Russia.

ABSTRACT
In the present work an efficient approach of the controlled formation of hybrid Au-Ag-C nanostructures based on laser-induced transformation of organometallic supramolecular cluster compound is suggested. Herein the one-step process of the laser-induced synthesis of hybrid multi-yolk-shell Au-Ag@a-C:H nanoparticles which are bimetallic gold-silver subnanoclusters dispersed in nanospheres of amorphous hydrogenated a-C:H carbon is reported in details. It has been demonstrated that variation of the experimental parameters such as type of the organometallic precursor, solvent, deposition geometry and duration of laser irradiation allows directed control of nanoparticles' dimension and morphology. The mechanism of Au-Ag@a-C:H nanoparticles formation is suggested: the photo-excitation of the precursor molecule through metal-to-ligand charge transfer followed by rupture of metallophilic bonds, transformation of the cluster core including red-ox intramolecular reaction and aggregation of heterometallic species that results in the hybrid metal/carbon nanoparticles with multi-yolk-shell architecture formation. It has been found that the nanoparticles obtained can be efficiently used for the Surface-Enhanced Raman Spectroscopy label-free detection of human serum albumin in low concentration solution.

No MeSH data available.


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Schematic presentation of Au-Ag@a-C:H NPs formation mechanism.
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f8: Schematic presentation of Au-Ag@a-C:H NPs formation mechanism.

Mentions: The following scheme of the NPs formation can be suggested on basis of the experimental data available. At the first stage, the complex absorbs 325 nm laser irradiation due to MLCT transition. It was found that the complex excitation into intraligand electron transition (250 nm) does not cause NPs formation. The photo-excitation of the molecule through MLCT results in the rupture of metallophilic bonds between central [Au10Ag12(C2Ph)20]2+ cluster core and [Au3(PP)3]3+ “belt” to leave in solution two independent species (Fig. 8). The latter species remains in solution and is not involved in the formation of NPs. The mass spectroscopic study of the resulting reaction mixture provides a strong support for the hypothesis given above. The ESI + mass spectrum of the final solution obtained after NPs centrifugation displays two dominant signals at 796 and 944 m/z (Figure S9, Supporting Information). The former is a combination of the signals generated by two independent species [Au3(PPh2(C6H4)3PPh2)3]3+ and [Au2(PPh2(C6H4)3PPh2)2]2+ derived from the gold-diphosphine “belt”, note that the dimer is thermodynamically stable compound isolated and characterized earlier (Figure S10, S11, Supporting Information)21. Another intense signal at 944 m/z corresponds to the product of partial recombination ([Au2(PPh2(C6H4)3PPh2)2(AuC2Ph)]2+, Figure S12, Supporting Information) of the reaction mixture components. The position of the signals and their isotopic distribution fit completely the composition given above (Figure S11, S13, Supporting Information).


Laser-induced transformation of supramolecular complexes: approach to controlled formation of hybrid multi-yolk-shell Au-Ag@a-C:H nanostructures.

Manshina AA, Grachova EV, Povolotskiy AV, Povolotckaia AV, Petrov YV, Koshevoy IO, Makarova AA, Vyalikh DV, Tunik SP - Sci Rep (2015)

Schematic presentation of Au-Ag@a-C:H NPs formation mechanism.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495562&req=5

f8: Schematic presentation of Au-Ag@a-C:H NPs formation mechanism.
Mentions: The following scheme of the NPs formation can be suggested on basis of the experimental data available. At the first stage, the complex absorbs 325 nm laser irradiation due to MLCT transition. It was found that the complex excitation into intraligand electron transition (250 nm) does not cause NPs formation. The photo-excitation of the molecule through MLCT results in the rupture of metallophilic bonds between central [Au10Ag12(C2Ph)20]2+ cluster core and [Au3(PP)3]3+ “belt” to leave in solution two independent species (Fig. 8). The latter species remains in solution and is not involved in the formation of NPs. The mass spectroscopic study of the resulting reaction mixture provides a strong support for the hypothesis given above. The ESI + mass spectrum of the final solution obtained after NPs centrifugation displays two dominant signals at 796 and 944 m/z (Figure S9, Supporting Information). The former is a combination of the signals generated by two independent species [Au3(PPh2(C6H4)3PPh2)3]3+ and [Au2(PPh2(C6H4)3PPh2)2]2+ derived from the gold-diphosphine “belt”, note that the dimer is thermodynamically stable compound isolated and characterized earlier (Figure S10, S11, Supporting Information)21. Another intense signal at 944 m/z corresponds to the product of partial recombination ([Au2(PPh2(C6H4)3PPh2)2(AuC2Ph)]2+, Figure S12, Supporting Information) of the reaction mixture components. The position of the signals and their isotopic distribution fit completely the composition given above (Figure S11, S13, Supporting Information).

Bottom Line: It has been demonstrated that variation of the experimental parameters such as type of the organometallic precursor, solvent, deposition geometry and duration of laser irradiation allows directed control of nanoparticles' dimension and morphology.The mechanism of Au-Ag@a-C:H nanoparticles formation is suggested: the photo-excitation of the precursor molecule through metal-to-ligand charge transfer followed by rupture of metallophilic bonds, transformation of the cluster core including red-ox intramolecular reaction and aggregation of heterometallic species that results in the hybrid metal/carbon nanoparticles with multi-yolk-shell architecture formation.It has been found that the nanoparticles obtained can be efficiently used for the Surface-Enhanced Raman Spectroscopy label-free detection of human serum albumin in low concentration solution.

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemistry, St. Petersburg State University, Universitetskii pr. 26, St. Petersburg, 198504, Russia.

ABSTRACT
In the present work an efficient approach of the controlled formation of hybrid Au-Ag-C nanostructures based on laser-induced transformation of organometallic supramolecular cluster compound is suggested. Herein the one-step process of the laser-induced synthesis of hybrid multi-yolk-shell Au-Ag@a-C:H nanoparticles which are bimetallic gold-silver subnanoclusters dispersed in nanospheres of amorphous hydrogenated a-C:H carbon is reported in details. It has been demonstrated that variation of the experimental parameters such as type of the organometallic precursor, solvent, deposition geometry and duration of laser irradiation allows directed control of nanoparticles' dimension and morphology. The mechanism of Au-Ag@a-C:H nanoparticles formation is suggested: the photo-excitation of the precursor molecule through metal-to-ligand charge transfer followed by rupture of metallophilic bonds, transformation of the cluster core including red-ox intramolecular reaction and aggregation of heterometallic species that results in the hybrid metal/carbon nanoparticles with multi-yolk-shell architecture formation. It has been found that the nanoparticles obtained can be efficiently used for the Surface-Enhanced Raman Spectroscopy label-free detection of human serum albumin in low concentration solution.

No MeSH data available.


Related in: MedlinePlus