科研之友
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摘要
The preparation and characterisation of a series of well-defined low generation (poly)amidoamine (PAMAM)-based dendrimers with end-grafted ethylene glycol ether moieties of type N(CH(2)CH(2)C(O) NHCH(2)CH(2)NR(2))(3) (3a, R = CH(2)CH(2)C(O)OCH(2)CH(2)OCH(3); 3b, R = CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5); 3c, R = CH(2)CH(2)CH(2)CH(2)O)(9)CH(3)), [CH(2)N(CH(2)CH(2)C(O)NHCH(2)CH(2)NR(2))(2)](2) (4, R = CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5)) and (R(2)NCH(2)CH(2)NHC(O)CH(2)CH(2))N[CH(2)CH(2)N(CH(2)CH(2)C(O)NHCH(2)CH(2)NR(2))(2)](2) (5a, R = CH(2)CH(2)C(O)O CH(2)CH(2)OCH(3); 5b, R = CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5): 5c, R = CH(2)CH(2)C(O)O(CH(2)CH(2)O)(9)CH(3)) and their application for the stabilisation of gold nanoparticles (Au NPs) is described. These dendrimers were prepared by a consecutive divergent synthesis methodology including Michael addition and amidation cycles. For comparison, amidoamine related model compounds N(C(3)H(7))R(2) (1, R = CH(2)CH(2)C(O)O (CH(2)CH(2)O)(2)C(2)H(5)) and [CH(2)NR(2)](2) (2, R = CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5)) were also synthesised to estimate the minimum required donating capabilities of the stabiliser. Loading the appropriate dendritic templates with H[AuCL(4)] (12) and subsequent reduction of the respective metallodendrimers with Na[BH(4)] produced dendrimer encapsulated gold colloids. The dendrimeric scaffold, the length of the ethylene glycols, the adjusted stabilizer:gold ratio and the duration of reaction time affects the average Au particle diameter in a range of 4.0 (+/- 0.9) to 58.5 (+/- 14.5) nm. Furthermore, depending on the nature of the stabiliser, nanoparticles were formed having spherical or multiple morphologies. Characterisation by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV/vis, and IR spectroscopy revealed that Au NPs are formed and protected inside the dendrimer scaffold.
- 出版日期2011-7-15
