(5r) Biophysical Engineering Strategies for the Development of Protein-Based Solar Convertors

We have engineered a novel nano-platform for the cost-effective production of enzyme based biocatalysts for applications in organic solvents. We incorporated an inexpensive nanostructured material as support in a two-step procedure only making use of simple electrostatic interactions. This will potentially help to expand the application of enzymes to a variety of processes of commercial interest including the production of commodities and pharmaceuticals. To fully understand the intricate surface-protein and protein-protein interactions as well as optimize our immobilization protocol, a number of state-of-the-art spectroscopic and nano-imaging tools were applied. The secondary and tertiary structural changes of the immobilized enzymes were monitored with Circular Dichroism, FTIR, and Fluorescence spectroscopy. Direct observation of the physical state of the enzyme molecules was achieved with AFM. Moreover, the mobility and adsorptive properties at the nanoscale were studied with Fluorescence Recovery After Photobleaching (FRAP) and Confocal Microscopy. A robust multiparametric model will be generated to adjust the immobilization conditions to prepare highly efficient biocatalysts for customized applications.

As an independent researcher, I expect to apply this knowledge for the development of protein-based nanobiophotonic devices capable of efficiently converting solar energy. These nanobiophotonic devices capture solar energy through immobilized protein photosystems isolated from natural sources such as bacteria or plants. The energy is transferred by specialized reaction centers involving a concerted cascade of chromophores. Further electrochemical reactions can be coupled to the transfer cascade to generate electricity. The major limitation for the commercialization of this technology is the instability of the biological components. This instability results in low conversion efficiency when compared with photovoltaic devices. The natural photosystems are highly sensitive multi-protein systems. A rational design of prototypes must be focused in properly tuning the protein-surface interactions responsible for the final protein conformation and consequently energy transfer properties. The success of this technology will assure a greener energy supply for a world with an increasing energetic demand.