@article{lou_lewis_gorman_he_2005, title={Detection of DNA point mutation by atom transfer radical polymerization}, volume={77}, ISSN={["1520-6882"]}, DOI={10.1021/ac050706h}, abstractNote={We report here a new DNA detection method in which polymer growth in atom transfer radical polymerization (ATRP) is used as a means to amplify detection signals. In this method, DNA hybridization and ligation reactions led to the attachment of ATRP initiators on a solid surface where specific DNA sequences were located. These initiators subsequently triggered the growth of poly(hydroxyethyl methacrylate) (PHEMA) at the end of immobilized DNA molecules and formed polymer brushes. The formation of PHEMA altered substrate opacity, rendering the corresponding spots readily distinguishable to the naked eye. A second ATRP reaction to form branched polymers on the surface drastically improved the visibility of DNA hybridization and significantly shortened the detection time. The resulting polymer film was characterized using infrared spectroscopy, ellipsometry, contact angle measurements, and atomic force microscopy. Direct visualization of 1 fmol of target DNA molecules of interest was demonstrated. A proof-of-principle experiment to detect DNA point mutation was conducted. The perfectly matched DNA targets were distinctively differentiated from those with mutations. The demonstrated capability to detect DNA mutation with direct visualization laid the groundwork for the future development of detector-free testing kits in single-nucleotide polymorphism screenings.}, number={15}, journal={ANALYTICAL CHEMISTRY}, author={Lou, XH and Lewis, MS and Gorman, CB and He, L}, year={2005}, month={Aug}, pages={4698–4705} }
 @article{lewis_gorman_2004, title={Scanning tunneling microscope-based replacement lithography on self-assembled monolayers. Investigation of the relationship between monolayer structure and replacement bias}, volume={108}, ISSN={["1520-6106"]}, DOI={10.1021/jp0379244}, abstractNote={Organothiolate self-assembled monolayers (SAMs) can be patterned using a scanning tunneling microscopy (STM) tip. Upon elevating the bias, the SAM is locally desorbed. By conducting this process in the presence of a second thiol component in a nonpolar solution (dodecane) above it, a different SAM component is locally introduced. Here, the influence of the chain length and headgroup of the initial SAM on this process is elucidated. SAMs composed of longer molecules require higher biases to effect this process, similar to the electrochemical desorption behavior of these molecules. When initial SAMs composed of headgroups other than methyl were studied, poor results were obtained:  features were broad and replacement occurred more inconsistently. Several possible explanations for this behavior are discussed.}, number={25}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Lewis, MS and Gorman, CB}, year={2004}, month={Jun}, pages={8581–8583} }