Establishing the potential of FSFs for BZD discrimination and enabling hardware for their measurement. Figure shows the FSF for exemplar BZDs from three structural classes represented in the illicit designer BZD market . From Figure , each of the different structural classes produces a different FSF, even within the same class. We note the similarities within the same structural classes are simple, tending to visually recognizable similarities. However, from these data it appears that even relatively minor substitutions about the core benzodiazepine group produce a unique FSF. For example, the presence of nitro groups on both clonazepam and flunitrazopam may influence FSF structure due to a strong electron withdrawing effect, narrowing the energy gap between electronic transitions and shifting fluorescence emission toward the red end of the spectrum . These data directly mirror our previous findings with synthetic cannabinoids . However, we note the fluorophore in BZDs shows a relatively lower quantum yield compared to synthetic cannabinoids (approximately 3 times lower) but varying significantly for individual molecules. Our data therefore suggests that the FSFs for benzodiazepines (Figure ) could be used to discriminate even structurally similar BZDs. Whilst FSFs appear to be discriminatory, clearly a benchtop fluorimeter is not a practical solution for community harm reduction. Size, technical complexity and speed effectively preclude its use. For this approach to have potential in the community, an ultra-simple, portable, rugged system is required. We have recently suggested a design for a miniature fluorimeter based on LED excitation and a small, rugged spectrometer . We acknowledge there are many such designs reported. Figure shows an implemented design that is battery operated and small. Briefly, the design leverages recent advances in very bright UV LEDs (~50 -100 mW) and exceptionally small, high-resolution spectrometers (dimensions; 4, 4, 2.5 cm). The design uses 12 LEDs that span the UV-A,B and C ranges, limited only by the commercial availability of LEDs.