Spectral and cyclic voltammetric characterization of self-assembled monolayers on gold of pyrene end-labeled oligonucleotide duplexes

1999 ◽  
Vol 77 (5-6) ◽  
pp. 1077-1084 ◽  
Author(s):  
R Scott Reese ◽  
Marye Anne Fox

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.

2007 ◽  
Vol 121-123 ◽  
pp. 495-498 ◽  
Author(s):  
Jun Hyung Park ◽  
Buyng Su Park ◽  
Gu Huh ◽  
Seung Hyun Lee ◽  
Hyun Sook Lee ◽  
...  

We report on the distribution of mixed self-assembled monolayers (SAMs) composed of biotinylated and diluent alkylthiolates for streptavidin immobilization. Two thiol derivatives, 11-mercapto-1-undecanol (MUOH) and 11-mercaptoundecanoic-(8-biotinylamido-3,6-dioxaoctyl) amide (MBDA), were employed for mixed SAM. These thiols formed self-assembled monolayer without local domain, and streptavidins were immobilized onto biotinylated gold surface without nonspecific binding. In order to find the optimized condition of immobilization of streptavidin, we controlled the mixing ratio of two kind thiols by colorimetric detection assay, and the immobilization was characterized by atomic force microscopy (AFM), scanning tunneling microscopy (STM), and ellipsometer.


2019 ◽  
Vol 10 ◽  
pp. 2275-2279
Author(s):  
Elisabeth Hengge ◽  
Eva-Maria Steyskal ◽  
Rupert Bachler ◽  
Alexander Dennig ◽  
Bernd Nidetzky ◽  
...  

Surface modifications of nanoporous metals have become a highly attractive research field as they exhibit great potential for various applications, especially in biotechnology. Using self-assembled monolayers is one of the most promising approaches to modify a gold surface. However, only few techniques are capable of characterizing the formation of these monolayers on porous substrates. Here, we present a method to in situ monitor the adsorption and desorption of self-assembled monolayers on nanoporous gold by resistometry, using cysteine as example. During the adsorption an overall relative change in resistance of 18% is detected, which occurs in three distinct stages. First, the cysteine molecules are adsorbed on the outer surface. In the second stage, they are adsorbed on the internal surfaces and in the last stage the reordering accompanied by additional adsorption takes place. The successful binding of cysteine on the Au surface was confirmed by cyclic voltammetry, which showed a significant decrease of the double-layer capacitance. Also, the electrochemically controlled desorption of cysteine was monitored by concomitant in situ resistometry. From the desorption peak related to the (111) surface of the structure, which is associated with a resistance change of 4.8%, an initial surface coverage of 0.48 monolayers of cysteine could be estimated.


2006 ◽  
Vol 252 (14) ◽  
pp. 5158-5167 ◽  
Author(s):  
Abdiaziz A. Farah ◽  
Raluca Voicu ◽  
Raluca Barjovanu ◽  
Farid Bensebaa ◽  
Kidus Tufa ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2893 ◽  
Author(s):  
Toshikazu Kitagawa ◽  
Takashi Kawano ◽  
Takahiro Hase ◽  
Ikuma Hayakawa ◽  
Katsuyuki Hirai ◽  
...  

The three-point adsorption of tripod-shaped molecules enables the formation of robust self-assembled monolayers (SAMs) on solid surfaces, where the component molecules are fixed in a strictly upright orientation. In the present study, SAMs of a rigid molecular tripod consisting of an adamantane core and three CH2SH groups were employed to arrange ferrocene on a gold surface through oligo(p-phenyleneethynylene) linkers. Cyclic voltammetry of the monolayers demonstrated high surface coverage of ferrocene, yet the molecular interaction among adjacent ferrocene units was negligible. This was because of the extended intermolecular distance caused by the bulky tripod framework. The rates of electron transfer from the ferrocene to the gold surface through different linker lengths were determined by electrochemical measurements, from which the decay factor for oligo(p-phenyleneethynylene) wire was evaluated.


2002 ◽  
Vol 16 (05n06) ◽  
pp. 161-169 ◽  
Author(s):  
IRENA KRATOCHVÍLOVÁ ◽  
ADRIANA ZAMBOVA ◽  
JEREMIAH MBINDYO ◽  
BAHARAK RAZAVI ◽  
JOSEF HOLAKOVSKÝ

An electric-field assisted assembly has been used to place rod-shaped, metal-organic, molecule-metal nanowires onto lithographically defined metal pads allowing the electrical characterization of metal-molecule self-assembled monolayer-metal containing nanowires. Our results show that the parameters of metal-molecule metal junctions are close to previously published data, so we have constructed systems containing insulating monolayers with reasonable properties.


2010 ◽  
Vol 22 (01) ◽  
pp. 25-31
Author(s):  
Jhen-Gang Huang ◽  
Adam Shih-Yuan Lee ◽  
Shu-Fang Chu ◽  
Yun-Han Lin ◽  
Chii-Wann Lin

The interfacial characteristics of self-assembled monolayer (SAM), that are applied in miniaturized sensor design, were strongly influenced by the SAM constitution. The electrochemical and interfacial characteristics of hybrid SAMs that constituted with ferrocenyl octanethiol ( FcC 8 SH ) and unsubstituted octanethiol ( C 8) or 2-mercaptopyrimidine (2-MPD) were investigated in this study. The peaks of anodic oxidation were observed at around 0.49 V (vs. Ag/AgCl ) in the FcC 8 SH/C 8 hybrid SAM. However, the oxidation potentials descended from 0.42–0.38 V as the molar fraction of FcC 8 SH was decreased from 0.8–0.2 in the FcC 8 SH /2-MPD hybrid SAM. On the other hand, the interfacial hydrophilicity of FcC 8 SH /2-MPD hybrid SAM was measured to be higher than the FcC 8 SH/C 8 hybrid SAM due to the random arrangement of SAM caused by the shape of 2-MPD. Then, the surface roughness of hybrid SAM and chain length of ferrocenyl alkanethiols were all considered to be the parameters of interfacial characteristics. In summary, doping of 2-MPD in SAMs might reduce the rigidity of ferrocenyl alkanethiol SAMs and increase the interfacial hydrophilicity. This result will be useful in the development of the low power consumption portable bioanalytical system. And a miniaturized bioanalytical system based on ferrocenyl SAMs would be developed in the future.


2011 ◽  
Vol 2 ◽  
pp. 826-833 ◽  
Author(s):  
Xianghui Zhang ◽  
André Beyer ◽  
Armin Gölzhäuser

This paper reports on the mechanical characterization of carbon nanomembranes (CNMs) with a thickness of 1 nm that are fabricated by electron-induced crosslinking of aromatic self-assembled monolayers (SAMs). A novel type of in situ bulge test employing an atomic force microscope (AFM) is utilized to investigate their mechanical properties. A series of biphenyl-based molecules with different types of terminal and/or anchor groups were used to prepare the CNMs, such as 4'-[(3-trimethoxysilyl)propoxy]-[1,1'-biphenyl]-4-carbonitrile (CBPS), 1,1'-biphenyl-4-thiol (BPT) and 4-nitro-1,1'-biphenyl-4-thiol (NBPT). The elastic properties, viscoelastic behaviors and ultimate tensile strength of these biphenyl-based CNMs are investigated and discussed.


2009 ◽  
Vol 25 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Guo-Qiang TAN ◽  
Hai-Yang BO ◽  
Hong-Yan MIAO ◽  
Ao XIA ◽  
Zhong-Liang HE

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