NSF-MRSEC

1. Electronic DNA Detection via Magnetic Nanoparticles Preconcentration R. Y. Lai and J. G. Redepenning Nebraska MRSEC The ability to detect DNA in complex samples, without the use of exogenous reagents, and in a reusable platform could revolutionize point-of-care disease diagnosis. A recently developed DNA sensor, namely the E-DNA sensor, is known to simultaneously meet these challenging demands. While various aspects of the sensor have been optimized, no attempt has been made to improve sensor fabrication efficiency and surface modification versatility. “Click” chemistry approaches are particularly powerful because they are extremely selective towards molecules containing azide and alkyne groups, therefore preventing unwanted side reactions which occur frequently in surface modifications. Thus motivated, we have adopted two “click” chemistry approaches to the fabrication of our sensors. The chemical-assisted approach requires the presence of a reducing agent, while the potential-assisted approach relies on the applied potential to generate the Cu(I) catalyst. The immobilization is an irreversible, covalent, and one-step reaction that results in stable attachment of the DNA probes. More importantly, the resultant DNA sensors show comparable sensor performance as sensors fabricated using a previously established method. These two DNA immobilization methods will then be employed in the modification of Fe3O4 particles to be used in the DNA pre-concentration step for amplified DNA detection. These programs are supported by the National Science Foundation, Division of Materials Research, Materials Research Science and Engineering Program, Grant 0820521. NSF-MRSEC