Seite - 105 - in Charge Transport in DNA - Insights from Simulations

CHAPTER8 Conclusion In this work, the charge transport and charge transfer capabilities of DNA un- der conditions resembling theexperimental setupwere investigated. Experimental investigationsofCT inDNAorotherbiomoleculesareoftenconductedundercon- ditions, which are not represented accurately in theoretical approaches. First, in common charge transport experiments the DNA strand is attached to electrodes withvaryingdistances. Second, single-molecule experiments (e.g.molecular junc- tions) are conductedwhere the solvent is removedpartiallywith a streamof gas. However, theexact amountofwaterpreservedat theDNAstrand isunknownand cannot bedeterminedby the experiments alone. Therefore, in thiswork a simula- tion setupwasdeveloped,which is able todescribe these experimental conditions within the limitsofcomputationalcosts. Basedonthissetup, calculationsofcharge transportandcharge transfer instretchedanmicrohydratedDNAwereperformed. These simulations gave insight into the properties of CT inDNAon an atomistic scale. Hence, the simulationswere not only able to explain the experiments, they are also able to predict the outcome of experiments andmake suggestions in ad- vance. As a start, in chapter 4 the structural features of microhydrated DNA and their changes upon stretching stresswere investigatedwith classicalMDsimulation. It has been shown that bothwater and counterions are structure-stabilizing factors 105