Impact of structure on the delayed luminescence of d-Glucose-based polymer chains.

Glucose is a natural chemical compound and is one of the most abundant organic molecules in nature. Plants and algae are able to produce it from water and carbon dioxide during photosynthesis, using energy of photons coming from the sun. It is very important in life processes because, in energy metabolism, Glucose is the most important source of energy in all organisms. As energy reservoir it is partially stored as a polymer, in plants mainly as starch and amylopectin and in animals as glycogen. Moreover it is used as cellulose, the most abundant carbohydrate, to strengthen plants and algae cell walls. In this paper we study the Delayed Luminescence from Glucose and its polymers, Amylose and Cellulose, composed by chains of glucose connected by different bond, as well as Glucose water solution, in order to acquire new knowledge on the mechanisms responsible for this phenomenon and check the possibility to give in-depth analysis of possible collective states present in Glucose-based structures. The phenomenon of DL in biological systems is not a byproduct, as one can naively expect. Instead, it is a property and necessity of the condensed matter, which can be also used as a tool to study the latter. It is a manifestation of the physical and biochemical processes in the system, on one hand side, and, on the other hand side, of its structural properties, in particular, of the presence and type of crystal-like structure, resulting in specific energy spectrum and electron transitions, as will be presented below. We show that the quantum yield and time trends of the Delayed Luminescence depend on the structure of systems under study. Significant differences in Delayed Luminescence parameters from cellulose before and after imbibition have been observed, indicating that Delayed Luminescence could be used to discriminate between various structures and follow the formation or demolition of them. The experimental results qualitatively agree with the soliton mechanism of the Delayed luminescence.