Nanocomposites by Electrostatic Interactions:  1. Impact of Sublayer Quality on the Organization of Functionalized Nanoparticles on Charged Self-Assembled Layers

Auer, Frank; Scotti, Michael; Ulman, Abraham; Jordan, Rainer; Sellergren, Börje; Garno, Jayne C.; Liu, Gang

doi:10.1021/la000647x

Cited by 50 publications

(35 citation statements)

References 10 publications

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“…110 A second bola layer made of R,ω-dicarboxylates has so far not been achieved. It would presumably arrange in a flat monolayer and not allow any further built-up processes.…”

Section: Multilayersmentioning

confidence: 99%

Bolaamphiphiles

2004

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“…110 A second bola layer made of R,ω-dicarboxylates has so far not been achieved. It would presumably arrange in a flat monolayer and not allow any further built-up processes.…”

Section: Multilayersmentioning

confidence: 99%

Bolaamphiphiles

2004

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“…Conditions could be found that allow repeated assembly–test–disassembly cycles of the layer structure. This restorable substrate concept was demonstrated for the detection of single mismatches in DNA hybridization experiments10 for selective detection of phosphate‐containing biomolecules,11 for the charge‐selective adsorption of plasma proteins,9 and for the rapid formation of dense layers of gold nanoparticles 12. After the “sensing” or adsorption event, the layers could be destabilized and the substrate restored.…”

Section: Introductionmentioning

confidence: 99%

Odd–Even Chain Length‐Dependent Order in pH‐Switchable Self‐Assembled Layers

Auer¹,

Nelles

Sellergren

2004

Chemistry A European J

Self Cite

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The reversible self-assembly of a series of bipolar amphiphiles, alpha,omega-bis(3- or 4-amidinophenoxy)alkanes (chain length n = 5-12), on mercaptoalkanoic acid-functionalized gold surfaces (chain length n = 10, 11, 14, 15) has been studied by in-situ ellipsometry, IR reflection absorption spectroscopy (IRAS), and atomic force microscopy (AFM). The layer order, amphiphile orientation, and tendency to form bilayers depends on the position of the amidine substituent, the alkyl chain length of both the amidine amphiphile and the underlying acid self-assembled monolayer (SAM), and whether the amidine alkyl chain contained an even or odd number of methylene groups. Thus, para-substituted bisbenzamidines containing more than six methylene groups (n>6) and with an odd number (n = 7, 9, 11) tended to form bilayered structures, whereas those containing an even number formed monolayers when adsorbed on SAMs of the long-chain acids (n = 14, 15). This behavior also correlated with the average tilt angle of the benzene moieties of the amphiphiles, as estimated by IRAS. The odd-numbered chains gave lower tilt angles than the even-numbered ones, and a possible model that accounts for these results is proposed. IRAS also revealed a higher order of the odd-numbered chains and an increasing hydrogen-bonding contribution with increasing chain length. Additional evidence for the proposed bilayered assemblies and their reversibility was obtained by AFM. Images obtained from the assembly of decamidine on a SAM of mercaptohexadecanoic acid in a pH 9 borate buffer revealed domains of similar size to that of the underlying acid SAM (20-30 nm), but less densely packed. By acidifying the solution, the second layer was destabilized and a very smooth layer with few defects appeared. Further acidification to pH 3 also destabilized the first layer.

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“…[1][2][3] These routes have enabled the conception and creation of novel nanostructured materials via the self-assembly of functionalized nanoparticles (NPs) [4][5][6][7][8][9][10][11][12][13] for application in nanoelectronics, medicine, and sensing. Investigations have demonstrated the formation of novel structured nanomaterials such as spherical, two-dimensional or network aggregates 5,14 via the self-assembly of gold 5 or silica 15 NPs functionalized with polymers, 5 peptides, 16 or DNA.…”

Section: Introductionmentioning

confidence: 99%