title: DNA-modified electrodes fabricated using copper-free click chemistry for enhanced protein detection.
abstract: A method of DNA monolayer formation has been developed using copper-free click chemistry that yields enhanced surface homogeneity and enables variation in the amount of DNA assembled; extremely low-density DNA monolayers, with as little as 5% of the monolayer being DNA, have been formed. These DNA-modified electrodes (DMEs) were characterized visually, with AFM, and electrochemically, and were found to facilitate DNA-mediated reduction of a distally bound redox probe. These low-density monolayers were found to be more homogeneous than traditional thiol-modified DNA monolayers, with greater helix accessibility through an increased surface area-to-volume ratio. Protein binding efficiency of the transcriptional activator TATA-binding protein (TBP) was also investigated on these surfaces and compared to that on DNA monolayers formed with standard thiol-modified DNA. Our low-density monolayers were found to be extremely sensitive to TBP binding, with a signal decrease in excess of 75% for 150 nM protein. This protein was detectable at 4 nM, on the order of its dissociation constant, with our low-density monolayers. The improved DNA helix accessibility and sensitivity of our low-density DNA monolayers to TBP binding reflects the general utility of this method of DNA monolayer formation for DNA-based electrochemical sensor development.
authors: Department of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors: Ariel L
authors: AL
authors: Furst
authors: Michael G
authors: MG
authors: Hill
authors: Jacqueline K
authors: JK
authors: Barton
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D057930:Click Chemistry; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004566:Electrodes; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D015394:Molecular Structure; D011506:Proteins / Q000032:analysis*; D035181:TATA-Box Binding Protein / Q000737:chemistry
chemical_list: D011506:Proteins; D035181:TATA-Box Binding Protein; D003300:Copper; D004247:DNA