Silica-based optical chemosensors for rapid and reliable on-site detection of gamma-hydroxybutyrate in beverages and oral fluids

The illicit use of gamma-hydroxybutyrate (GHB) in drug-facilitated crimes underscores the urgent need for rapid and reliable detection technologies. This study introduces two innovative silica-based nanosensors that offer real-time, on-site detection of GHB in spiked beverages at concentrations typical of chemical submission cases. Both chemosensors are based on silica nanoparticles functionalized with 2-aminonaphtoxazole derivatives. The first nanosensor, modified with a p-nitroaniline chromogenic unit, enables a visible color change for immediate visual identification, while the second incorporates a fluorescein derivative for high-sensitivity detection via fluorescence. Both nanosystems demonstrate exceptional specificity to GHB, with minimal interference from other substances. Moreover, the solid-phase integration of these nanosensors onto hydrophobic cellulose-based substrates enhances their portability and user-friendliness, making them suitable for nightlife venues and forensic applications. Finally, chromogenic precursor 1 has proven to be an excellent chemosensor for the visual detection of GHB in oral fluid, with a calculated LOD of 19.2 μM, and a linear response in the 32-132 μM range.