Computational modeling of biologically and technologically relevant photochemical processes initiated by visible and UV light and modeling of charge transfer along DNA stacks of potential interest for nanosciences.
Our main research topics are:
• Photochemistry and photophysics of the DNA nucleobases. Here we focus on modeling the interaction of DNA with UV light. Our research is centered on the nucleobases, which are the main UV absorbing DNA components. With our calculations we aim to interpret highly resolved laser spectroscopy experiments carried out on model systems and on DNA itself to study the effect of UV on natural DNA. Thus, we have determined the mechanisms that allow for a benign dissipation of the UV excitation energy to avoid processes that could induce mutations, by calculating the potential energy surfaces for the decay.
• Mechanistic basis of photoprotectors. Photoprotectors are molecules used as additives in industry to protect materials. They absorb radiation and dissipate it in an efficient and benign way, protecting the material from light-induced degradation. The chemical reaction that regulates this process is a hydrogen transfer in the excited state, and we have studied that factors that are responsible for the efficiency of the benign decay and competing, degrading paths that should be avoided to increase the efficiency.
• Electron transfer along DNA stacks. Experiments carried out on DNA by research groups from Europe, the USA and Japan have shown that if an electronic charge is injected into DNA it can migrate along the central column formed by the stacked nucleobases. This has opened the way for the possible use of DNA as a conductor or semiconductor material in nanotechnology. Our aim in this field is to determine the parameters that govern the charge transfer to provide the physical basis for future applications based on this process. Thus, we aim to calculate how the charge migration rate and electrical conductivity depend on the DNA sequence and the interaction with environment. We have also considered how the charge transfer properties depend on the structural fluctuations of DNA and its surroundings, and how they are affected by the complexation with polypeptides and proteins.
• Methodological developments. Our main methodological aim is the mathematical analysis of the calculated potential energy.