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Here we demonstrate a purely electrochemical approach for monitoring the electric field-induced melting of surface-bound DNA duplexes tethered to gold surfaces using standard surface attachment chemistry, i.e. single thiol-Au bonds. The sensitivity of square wave voltammetry is combined with the electric fields generated during programmed sequences of chronoamperometric pulses to enable a method for DNA analysis that can be carried out at room temperature without need for parallel spectroscopic monitoring. Electrochemical melting curves are obtained using both scanning potential pulses and constant potential pulses, which are analyzed to assess duplex stability and the extent of thiol desorption. The melting behavior is found to depend on the pulse potential and pule time. Under optimized conditions, thiol reduction is minimized and DNA duplexes can be discriminated based on the presence of a single base pair mismatch. The method is found to be less sensitive to the duplex length, presumably due to the rapid decay of the electric field away from the electrode surface. Based on these results, a simple model is proposed in which maintenance of the double-layer charge by accumulation of ions from the bulk of solution competes with electric field-induced loss of the negatively-charged DNA at a given applied potential.

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In recent years a significant amount of research has been conducted with the objective of improving efficiency of aircraft operations through optimized aircraft trajectories, thereby reducing harmful greenhouse gas (GHG) emissions such as CO2. However, as we look at the aviation system more holistically, we discover that there is a serious lack of comprehensive research that addresses reduction of GHG emissions at airports. Although the need for reduction in airport GHG emissions clearly exists, only a few US state or federal policies require airport operators to reduce such emissions. As a response to such a need, this paper develops the methodology for establishing more sustainable airports, analyzes mitigation strategies regarding specific airport operations, and develops a database for emission-tracking that would greatly assist airport officials in making their airport more sustainable. Establishing a precedent for analyzing emissions from airports would prove an integral part in evaluating other sustainability initiatives. This area of research has significant potential for reducing airport emissions, which in the wake of anthropogenic climate change is vital to future sustainability of air transportation.