The recognition of biomarkers of the Alzheimer’s disease (AD) can assist diagnosis, help towards drug development and targeted therapeutics, and monitor for safety. D-amino acids (Daa) play an important role in numerous (patho)physiologies including schizophrenia, amyotrophic lateral sclerosis, and age-related disorders as cataract, atherosclerosis and Alzheimer's disease. D-serine and D/L serine ratio in serum have been proposed as biomarkers for AD progression. Knowledge related to the role of Daa in the pathogenesis of AD will facilitate novel therapeutic treatments and hence, improve the patient's quality of life. An accurate, timely diagnosis and simple method is crucial to access early treatments and the xanthone scaffold has the desirable photophysical properties to be explore as fluorophores. XANTAAL proposes to investigate chiral xanthone derivatives as enantioselective probes for the quantification of D/L amino acids ratio for AD diagnoses. New xanthone-based sensor denote potential for Patent registration and future commercialization.