Surface immobilization Self assembled

Sapsford, K. E., I. L. Medintz, J. P. Golden, J. R. Deschamps, H. T. Uyeda, and H. Mattoussi. Surface-immobilized self-assembled protein-based quantum dot nanoassemblies. Langmuir 20, 7720-7728 (2004). 

In this part we will describe recent achievements in the development of biosensors based on DNA/RNA aptamers. These biosensors are usually prepared by immobilization of aptamer onto a solid support by various methods using chemisorption (aptamer is modified by thiol group) or by avidin-biotin technology (aptamer is modified by biotin) or by covalent attachment of amino group-labeled aptamer to a surface of self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA). Apart from the method of aptamer immobilization, the biosensors differ in the signal generation. To date, most extensively studied were the biosensors based on optical methods (fluorescence, SPR) and acoustic sensors based mostly on thickness shear mode (TSM) method. However, recently several investigators reported electrochemical sensors based on enzyme-labeled aptamers, electrochemical indicators and impedance spectroscopy methods of detection. 

Several useful schemes for attaching nucleic acid probes onto electrode surfaces have thus been developed [2-8]. The exact immobilization protocol often depends on the electrode material used for signal transduction. Common probe immobilization schemes include attachment of biotin-functionalized probes to avidin-coated surfaces [15], self-assembly of organized monolayers of thiol-functionalized probes onto gold transducers [16], carbodiimide covalent binding to an activated surface [17], as well as adsorptive accumulation onto carbon-paste or thick-film carbon electrodes [15-30]. 

This result shows that DNA-conjugated TA-polyallylamine can be immobilized on a surface via self-assembly. To verify that this result is due to self-assembly, DNA-conjugated TA-polyallylamine lacking TA side chains was used as a control. This polymer was also retained on the surface after washing (Fig. 6A, curve II) the residual response (1900 response unit (RU)) was probably due to nonspecific interaction between the DNA side chains of the polymer and the gold surface of the sensor. However, the amount of bound polymer was less than that for the DNA-conjugated TA-polyallylamine. The SPR response in the presence of polyallylamine alone (without DNA) was low (only 780 RU) after washing (Fig. 6A, curve III). 

Mills, W. H. (1922). LIV.-The cyanine dyes. Part IV. Cyanine dyes of the benzothiazole series.. Chem. Soc. Trans. Vol. 121, pp. 455-466, ISSN. 0368-1645 Mohanazadeh, F. Aghvami, M (2007). Thiazolium Salt Immobilized on Ionic Liquid An Efficient Catalyst and Solvent for Preparation of a-Hydroxyketones. Phosphorus, Sidfitr Silicon Relat. Elem. Vol. 182, No. 10, pp. 2467-2475, ISSN. 1042-6507 Motesharei, K Myles, D. C (1997). Multistep Synthesis on the Surface of Self-Assembled Thiolate Monolayers on Gold Probing the Mechanism of the Thiazolium-Promoted Acyloin Condensation. /. Am. Chem. Soc. Vol. 119, No. 28, pp. 6674-6S75, ISSN. 0002-7863... 

A large number of potential applications for organized protein monolayers have recently motivated considerable research activity in this field (Boussaad et al. 1998, Kiselyova et al. 1999). Construction of specific interaction-directed, self-assembled protein films has been performed at the air-water interface. The Langmuir-Blodgett (LB) technique has been extensively used to order and immobilize natural proteins on solid surfaces (Tronin et... 

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

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... 

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