Major
Chemistry
Research Abstract
Electrostatic melting is a recently developed electrochemical tool that can be used to interrogate DNA stability, allowing for discrimination of double-stranded DNA (dsDNA) by base-pair sequence or the presence of mismatches, deletions, and other mutations (1). This type of analysis has potential applications in point-of-care diagnostics. Here we explore the dependence of temperature and potential on the kinetics of electrostatic melting in an effort to better understand the mechanism. Previous studies, by another group, have shown that the potential at which electrostatic melting occurs decreases with temperature in the range 10 – 18 °C, i.e. the melting becomes easier at higher temperatures up to 18 °C. On the other hand, the authors found no effect of temperature above 18 °C (2). Unlike previous studies, the work presented here examines the kinetics of electrostatic melting at relatively low melting potentials (300 – 500 mV vs Ag/AgCl reference electrode). We show that as the temperature increases, the extent of melting and rate of melting increases in the range 20 – 50 °C. Notably, the kinetics follow Arrhenius behavior, thus allowing us to determine the electric-field modulated activation energies of melting as a function of melting potential. Based on these measurements, we hope to determine optimal temperature and potential ranges for discrimination of dsDNA. / References 1. S. Mahajan, J. Richardson, T. Brown and P. N. Bartlett, Journal of the American Chemical Society, 130, 15589 (2008). 2. E. Papadopoulou, M. Meneghello, P. Marafini, R. P. Johnson, T. Brown and P. N. Bartlett, Bioelectrochemistry, 106, 353 (2015).
Faculty Mentor/Advisor
Ryan West
Included in
Temperature-dependence of electrostatic DNA melting
Electrostatic melting is a recently developed electrochemical tool that can be used to interrogate DNA stability, allowing for discrimination of double-stranded DNA (dsDNA) by base-pair sequence or the presence of mismatches, deletions, and other mutations (1). This type of analysis has potential applications in point-of-care diagnostics. Here we explore the dependence of temperature and potential on the kinetics of electrostatic melting in an effort to better understand the mechanism. Previous studies, by another group, have shown that the potential at which electrostatic melting occurs decreases with temperature in the range 10 – 18 °C, i.e. the melting becomes easier at higher temperatures up to 18 °C. On the other hand, the authors found no effect of temperature above 18 °C (2). Unlike previous studies, the work presented here examines the kinetics of electrostatic melting at relatively low melting potentials (300 – 500 mV vs Ag/AgCl reference electrode). We show that as the temperature increases, the extent of melting and rate of melting increases in the range 20 – 50 °C. Notably, the kinetics follow Arrhenius behavior, thus allowing us to determine the electric-field modulated activation energies of melting as a function of melting potential. Based on these measurements, we hope to determine optimal temperature and potential ranges for discrimination of dsDNA. / References 1. S. Mahajan, J. Richardson, T. Brown and P. N. Bartlett, Journal of the American Chemical Society, 130, 15589 (2008). 2. E. Papadopoulou, M. Meneghello, P. Marafini, R. P. Johnson, T. Brown and P. N. Bartlett, Bioelectrochemistry, 106, 353 (2015).
