D-amino acids (D-AA) are recognised to play an important role in numerous (patho)physiologies including schizophrenia, amyotrophic lateral sclerosis, age-related cataracts, atherosclerosis, and Alzheimer Disease (AD). For example, D-serine and D/L serine ratio in serum have been proposed as biomarkers for AD progression. Understanding the role of D-AA related to the pathogenesis of AD will facilitate novel therapeutic treatments and improve patient's quality of life. An accurate, timely diagnosis and simple method is crucial to access early treatments. Currently, fluorescent probes with chemoselectivity and enantioselectivity to recognized AA are rare. The xanthone and rhodamine molecules have excellent photochemical properties, and its derivatives are used as fluorescent dyes and probes. Hence, XRED-AA proposes to investigate functionalized chiral derivatives of xanthone and rhodamine as chemoselectivity and enantioselective probes for quantification of D/L amino acids ratio for AD diagnoses. The biological models used to validate the design probes will aim the study of the Blood-Brain Barrier (BBB) permeability and nanoengineered drug delivery.