Methylene blue: A Trendy Photosensitizer in Medicine and in Solar-Energy Conversion Systems

The photosensitizer methylene blue (MB) has been investigated as a deoxyribonucleic acid (DNA) intercalant with the main objective of understanding the chemical/physical processes, which occur when adequate wavelength light is impinging on DNA intercalated with MB. This understanding is crucial for the creation of dynamic phototherapy procedures and for the development of new dye sensitized solar cells. During this work we developed and optimized all the conditions to efficiently produce [MB/DNA] multi-layered films by self-assembly. Our study revealed that pH strongly influences the growth of our multilayer films. Our UV studies revealed that the UV radiation causes damage of DNA through opening of aromatic ring and by breaking the DNA phosphate groups. The FT-IR studies on cast films with [MB/DNA] revealed that the denaturation ratio decreases as the irradiation increases, meaning that MB is an intercalant of DNA chain. This study paves the way to develop new dye sensitized solar cells which employ inexpensive materials and take advantage of the intercalation process in order to adjust the intermolecular arrangement of the donor/acceptor molecules to improve the device performance.