Dr. Lara Halaoui

Associate Professor
Physical Chemistry

Postdoctoral Fellow, University of Texas at Austin, Advisor: Allen J. Bard (1998) Ph.D. Duke University, Advisor: Louis A. Coury, Jr. (1993-1997) B.S. with Distinction, American University of Beirut (1992).

• My research interests are focused on the synthesis of potential building blocks for the preparation of carbocyclic oligodeoxynucleotide (ODN) analogs. The demand for synthetic ODNs has increased rapidly during the last decade. Significant potentials of these polymers range from their uses in diagnostic (biosensors) to therapeutic applications (antisense, antigene). We are interested in the design and synthesis of a variety of non-conjugated dienes with nucleic bases attached. One series includes 1,6-heptadienes with nucleic bases attached either directly or via a linker to the central carbon. Another series includes a diallylamino group substituent attached to the nucleic bases. Our interest in these molecules stems from their potential utility to cyclopolymerize and form carbocyclic ODN analogs with a cyclopentane ring replacing the furanose ring and a hydrocarbon backbone replacing the phosphodiester backbone in natural ODNs. These analogs are expected to be physiologically more stable than their natural counterparts, and, therefore, less susceptible to enzymatic degradation in biological environments.

  Our main research efforts are focused on the synthesis, self-assembly, and exploration of the photoelectrochemical, optical, and electrical properties of nanoparticles and ensembles of nanoparticles by means of spectroscopic, photoelectrochemical, and scanning probe microscopy techniques.

  For example, we synthesize semiconductor (e.g., CdS) and metal (e.g., Pt) nanocrystallites using anionic polyelectrolytes as surface capping agents, and assemble them in multilayers at surfaces previously modified with cationic polyelectrolyte polymers, and study the factors affecting film growth.

  We also explore the processes of light-induced charge separation, hopping at interfaces, recombination, and transfer to solution species or to electrode surfaces in semiconductor nanoparticles and ensembles of nanoparticles using photoelectrochemical techniques. Our group is also involved in the elucidation of mechanistic redox chemistry of novel organic molecules using electrochemical techniques.

Selected Publications

• Electroluminescence at GaN and Gax In1-xN Electrodes in Aqueous Electrolytes, Electrochem. Solid-State let.1998, 1, 142 (with C. Hung, A. J. Bard, P. A. Grudowski, R. D. Dupuis, J. Molstad and F. J. Disalvo).

• STM and TS Study of InAs Quantum Dots Immobilized on Au and Pt Surfaces,. Chem. Mater. 2000, 12, 1205 (with R. L. Wells and L. A. Coury. Jr.).

• Reduction of Nitric Acid to Hydroxylamine at Glassy Carbon Surfaces Modified by the Reduction of p-Phenylenediamine and p-Aminophenol in 1.0 M Nitric Acid- A Scanning Electrochemical Microscopy Study, J. Electrochem. Soc. 2001, 148, E386 (with H. Sherifian and A. J. Bard).

• Layer-by-Layer Assembly of Polyacrylate-Capped CdS Nanoparticles in Poly(diallyldimethylammonium chloride) on Solid Surfaces, Langmuir 2001, 17, 6747.