Caracterizações espectroscópicas e de tempo de vida em soluções fluorescentes inseridas em saliva artificial em função do pH

Abstract

The present work presents the spectroscopic and lifetime characterizations of fluorescent solutions inserted in artificial saliva. Fluorescein and natural dyes, extracted from the leaves of Tradescantia pallida purpurea, were prepared and inserted in artificial saliva at the different potential of hydrogen (pH ~3.5-11,9) values. Spectroscopic measurements of absorption, fluorescence, and time-resolved fluorescence were performed in the investigated samples as a function of pH. In pure artificial saliva, the thermo-optic coefficient (dn/dT) was determined using an interferometer as a function of pH. Saliva was chosen for lubrication, chewing, swallowing, and digestion. There are many advantages to using saliva as a biofluid. Because its collection is quick, easy, inexpensive, and non-invasive. Furthermore, saliva may reflect the physiological and pathological state of the body and the pH of saliva is an indicator for some diseases. This work aims to evaluate fluorescent dyes, fluorescein, and natural dye, as possible pH-dependent biosensors for disease diagnosis, since the pH of human saliva can vary in case of pathologies.