Oligonucleotides monolayer

Kohler J.M., Csaki A., Reichert J., Moller R., Straube W., Fritzsche W., Selective labeling of oligonucleotide monolayers by metallic nanobeads for fast optical readout of DNA-chips, Sens Act B 2001 76 166-172. 

This process gives sharp voltammetric peaks that offer e.g. preeise surface coverage determination at well-defined surfaees. Use of single-erystal, say Au(lll)-surfaees has substantiated that densely paeked thiolated oligonucleotide monolayers, almost resembling a moleeular brush , ef section 4 are formed.A similar conclusion was reported by Palacek and associates who exploited the intrinsically atomically planar nature of a liquid mercury electrode surfaee. The notion of two-dimensional condensation has been invoked for sueh phenomena. 

Hyun J, Kim J, Craig SL, ChiUcoti A (2004) Enzymatic nanolithography of a self-assembled oligonucleotide monolayer on gold. J Am Chem Soc 126 4770-4771... 

Luderer F, Walschus U (2005) Immobilization of Oligonucleotides for Biochemical Sensing by Self-Assembled Monolayers Thiol-Organic Bonding on Gold and Silanization on Silica Surfaces. 260 37-56... 

The potential use of SERS in biodiagnostic tests has been demonstrated through the use of immobilized monolayers of bioreceptors, including oligonucleotides and antibodies. The use of surface-enhanced Raman gene... 

Belosludtsev and coworkers (2001) propose that the unmodified probes on the weakly cationic surface, although prevented from diffusing off the surface because of electrostatic interaction, nevertheless are available for hybrid nucleation. They suggest that such probe behavior could be viewed similarly to behavior observed in a liquid crystal matrix. This would be in sharp contrast to models describing the covalent attachment of short oligonucleotides as "oligo lawns" or monolayers of coiled probes (see Figure 3.6). 

In a recent report, 19- or 20-residue thiolated oligonucleotides were used in an exchange reaction with glutathione monolayer-protected gold clusters. After thiol substitution, the resulting DNA-nanoparticle conjugates can be separated by gel electrophoresis on the basis of the number of bound oligonucleotides and assembled with one another by DNA-DNA hybridization [151]. 

Figure 5.49 Time course for the limiting current at gold modified with the oligonucleotide 2/4 in methylviologen (MV+2) solution (0.1 mM in 0.1 NaCl) at an applied potential of 0 mV (vs. Ag/AgCl). The inset shows the time domain in which the electrode is alternatively exposed to and shielded from 346 nm illumination the arrows indicate when the shutter is open or closed. From R. S. Reese and M. A. Fox, Spectral and cyclic voltammetric characterization of self-assembled monolayers on gold of pyrene end-labeled oligonucleotide duplexes, Can.. Chem., 77,1077-1084 (1999), with permission from The National Research Council of Canada...

To arrange AuNPs into a monolayer, Simon and coworkers [74] reported a simple protocol via the oligonucleotides complementary immobiUzation. 5 -Amino-modified oligonucleotide was immobilized on the substrate surface first, and then, 15 nm gold particles modified with thiolated DNA oligomers were coupled to the surface through DNA base pairing. The resulted nanoparticle monolayers were demonstrated to have a thermally activated conductivity. A similar approach has been used to insert a liposome into a DNA chip [75] (Fig. lib). 

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