In this paper we report the possibility of using the X-ray powder diffraction (XRPD) technique to detect the gamma-hydroxybutyric acid (GHB) as its sodium salt in different beverages but because it is not possible to freely buy them, beta-hydroxybutyric acid (BHB) and its sodium salt (NaBHB) were used as a model to fine tune an X-ray diffraction method for the qualitative analysis of the sodium salt of GHB. The method requires a small quantity of beverage, and an easy sample preparation, that consists only in the NaOH addition to the drink and a subsequent drying step. The dry residue obtained can be easily analyzed with XRPD using a single crystal X-ray diffractometer to exploit its high sensitivity that allows very fast patterns collection. Several beverages with different NaBHB:NaOH molar ratios were tested and the results show that NaBHB is detected in all drinks analyzed when NaBHB:NaOH molar ratio is 1:50 using characteristic peak at very low 2θ values that permits to detect its presence also in complex beverage matrices. Moreover, depending on the NaOH amount added, shifting and/or splitting of the characteristic peak of the NaBHB salt was observed, and the origin of this behavior was investigated.

Chitosan is a biodegradable polymer derived from chitin, that is a versatile material for various biological applications for its attractive properties such as biocompatibility, biodegradability, and non-toxicity. Furthermore, chitosan possesses Second Harmonic Generation properties, that are useful for bio-sensing applications. In this work we explored the possibility to exploit chitosan-based nanospheres as SHG-based bio-sensors, and also as carriers of 89Sr radionuclide, an Active Pharmaceutical Ingredient for radiopharmaceutical treatments in cancer therapy. To load opportunely the Sr ion on the nanospheres, we used a fructose-based Metal Organic Framework, of formula [Sr(C6H12O6)2(H2O)2]Cl2·H2O, because the sugar was able to drive the Sr ions on the chitosan matrix. The Sr-loaded chitosan nanospheres were synthetized, characterized, and their SHG response was measured. The results encouraged us to propose the nanospheres for theranostic purposes, i.e. at the same time valuable for both therapy and diagnostic applications.