Electrochemical and Raman characterization of molecular recognition sites in self-assembled monolayers

Self-assembled monolayers of sulfur-terminated oligonucleotide duplexes were formed on flat gold surfaces, either by exposure of a self-assembled monolayer bearing one oligonucleotide strand to the complementary strand or by preformation of a oligonucleotide duplex that was then deposited on a fresh gold surface. Virtually identical spectral behavior was observed whether the duplex was produced before deposition or by in situ complementary association. With a duplex bearing an appropriate pyrene end-label, the resulting thin film was photoresponsive. Surface emission measurements show no evidence for pyrene aggregation on the modified surfaces. The polarity of the photocurrent, reflecting photoinduced electron transfer initiated by photoexcitation of pyrene, is opposite that expected from the oligonucleotide-mediated reduction of the appended pyrene excited state.Key words: oligonucleotide, self-assembled monolayer, duplex formation, photoelectrochemistry, surface emission.

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Electrochemical characterization of self-assembled monolayers (SAMs) of thiophenol and aminothiophenols on polycrystalline Au: Effects of potential cycling and mixed SAM formation

Journal of Electroanalytical Chemistry ◽

10.1016/j.jelechem.2008.03.015 ◽

2008 ◽

Vol 619-620 ◽

pp. 87-97 ◽

Cited By ~ 21

Author(s):

V. Ganesh ◽

Ravi R. Pandey ◽

B.D. Malhotra ◽

V. Lakshminarayanan

Keyword(s):

Electrochemical Characterization ◽

Self Assembled Monolayers ◽

Potential Cycling ◽

Assembled Monolayers ◽

Self Assembled

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X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.3.2 ◽

2012 ◽

Vol 3 ◽

pp. 12-24 ◽

Cited By ~ 13

Author(s):

Hicham Hamoudi ◽

Ping Kao ◽

Alexei Nefedov ◽

David L Allara ◽

Michael Zharnikov

Keyword(s):

Chain Length ◽

Photoelectron Spectroscopy ◽

Self Assembled Monolayers ◽

Phenylene Ethynylene ◽

X Ray ◽

Molecular Length ◽

Assembled Monolayers ◽

Self Assembled ◽

Gold Thiolate

Self-assembled monolayers (SAMs) of nitrile-substituted oligo(phenylene ethynylene) thiols (NC-OPEn) with a variable chain length n (n ranging from one to three structural units) on Au(111) were studied by synchrotron-based high-resolution X-ray photoelectron spectroscopy and near-edge absorption fine-structure spectroscopy. The experimental data suggest that the NC-OPEn molecules form well-defined SAMs on Au(111), with all the molecules bound to the substrate through the gold–thiolate anchor and the nitrile tail groups located at the SAM–ambient interface. The packing density in these SAMs was found to be close to that of alkanethiolate monolayers on Au(111), independent of the chain length. Similar behavior was found for the molecular inclination, with an average tilt angle of ~33–36° for all the target systems. In contrast, the average twist of the OPEn backbone (planar conformation) was found to depend on the molecular length, being close to 45° for the films comprising the short OPE chains and ~53.5° for the long chains. Analysis of the data suggests that the attachment of the nitrile moiety, which served as a spectroscopic marker group, to the OPEn backbone did not significantly affect the molecular orientation in the SAMs.

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