Microelectrode Array

January 20, 2011

Site-Selective, Cleavable Linkers: Quality Control and the Characterization of Small Molecules on Microelectrode Arrays

Bi, Bo; Huang, Richard Y.-C.; Maurer, Karl; Chen, Ceng; Moeller, Kevin D.

Journal of Organic Chemistry 2011, 76(21), 9053-9059

A “safety-catch” linker strategy has been used to release a portion of the products of a Diels-Alder reaction conducted on a microelectrode array for characterization of stereochem.  The attachment and cleavage of org. compds. from the surface of selected electrodes in the array can be accomplished by site-selective generation of base or acid at the electrode.  It was found that the surface of the array had a minor influence on the stereochem. of the Diels-Alder reaction, leading to slightly more of the exo-product relative to a similar soln.-phase reaction.


November 23, 2010

Building Addressable Libraries: Site-Selective Use of Pd(0) Catalysts on Microelectrode Arrays

Libo Hu, Melissae Stuart, Jun Tian, Karl Maurer, and Kevin D. Moeller

J. Am. Chem. Soc., 2010, 132 (46), pp 16610–16616

Site-selective Pd(0)-catalyzed reactions have been developed to functionalize a microelectrode array. Heck, Suzuki, and allylation reactions have all been accomplished. The reactions are compatible with both 1K and 12K arrays and work best when a nonsugar porous reaction layer is used. Suzuki reactions are faster than the Heck reactions and thus require more careful control of the reactions in order to maintain confinement. The allylation reaction requires a different confining agent than the Heck and Suzuki reactions but can be accomplished nicely with quinone as an oxidant for Pd(0).
October 29, 2009

A New Porous Reaction Layer for Developing Addressable Molecular Libraries

Libo Hu, Jennifer L. Bartels, Jeremy W. Bartels, Karl Maurer and Kevin D. Moeller

J. Am. Chem. Soc., 2009, 131(46), 16638–16639

A new diblock copolymer-derived porous reaction layer for microelectrode arrays has been tested for its stability and its compatibility with both site-selective synthesis and electrochemical signaling experiments. The diblock copolymer consisted of a cinnamoyl-substituted polymethacrylate block for attachment to the surface of the array and a bromo-substituted polystyrene block for selective functionalization of the surface proximal to microelectrodes in the array. Site-selective Suzuki, Heck, and Cu(I)-coupling reactions were all performed on the new reaction layer along with electrochemical impedance studies.


July 6, 2009

Building Addressable Libraries: Site-Selective Lewis-Acid (Sc(III)) Catalyzed Reactions

Bo Bi, Karl Maurer, and Kevin D. Moeller.
Angew. Chem. Int. Ed. Eng. 2009, 48, 5872

Lewis acid-catalyzed reactions have been site-selectively conducted on arrays having either 1024 microelectrodes cm-2 or 12,544 microelectrodes cm-2. The reactions employ Sc(III) generated at the microelectrodes as the Lewis acid, and confine the reagent to the electrodes utilized in its generation with the use of  2-phenylbenzthiazole  as a solution phase reductant. A multicomponent synthesis of a tetrahydropyran, a Diels-Alder reaction, and an esterification reaction were all shown to be compatible with the electrochemical generation of the Sc(III) and the confinement strategy.