Flualprazolam and flubromazolam: Blood concentrations and prevalence of two novel psychoactive substances in forensic case work in Ontario, Canada.

Flualprazolam and flubromazolam are synthetic benzodiazepines that have not been approved for use in humans. They are categorized as novel psychoactive substances (NPS), and have been increasingly encountered in forensic case work. This report examines information from cases analyzed for flualprazolam and flubromazolam between July 1 and December 31, 2021 to identify the prevalence, trends and demographic data associated with these novel drugs in Ontario, Canada. Flualprazolam was identified in blood, serum or liver in 395 death investigations, 108 impaired driving and five sexual assault cases. Among all case types, blood concentrations were determined in 123 individuals aged 19-66 years. In impaired driving and sexual assault cases, flualprazolam blood concentrations ranged from <1.3 to 227 ng/mL (median 11.0 ng/mL), whereas a range of 3-59 ng/mL (median 6.8 ng/mL) was reported in death investigations. Flubromazolam was identified in blood, serum or liver in 137 death investigations, 55 impaired driving and one sexual assault case. Blood concentrations ranged from <1.3 to 323 ng/mL in 65 individuals, aged 14-61 years. In impaired driving and sexual assault cases, flubromazolam blood concentrations ranged from <1.3 to 323 ng/mL (median 7.7 ng/mL), which overlapped with the range of 2-220 ng/mL (median 8.0 ng/mL) reported in death investigations. Other drugs were frequently detected with flualprazolam and flubromazolam with opioids identified in more than 89% of positive flualprazolam and flubromazolam cases. These results demonstrated the prevalence of flualprazolam and flubromazolam in Ontario, Canada. Trends showed that over the 6-month period, as the number of flubromazolam cases decreased, the incidences of flualprazolam increased. An overlap in concentrations of these drugs was observed in both death investigations and cases involving living individuals. These data provide valuable information for the scientific community regarding the use of these drugs in antemortem and postmortem casework.

Intrinsic "Turn-On" Aptasensor Detection of Ochratoxin A Using Energy-Transfer Fluorescence.

Ochratoxin A (OTA) is an intrinsically fluorescent phenolic mycotoxin that contaminates a wide range of food products and is a serious health threat to animals and humans. An OTA binding aptamer (OTABA) that folds into an antiparallel G-quadruplex (GQ) in the absence and presence of target OTA has been incorporated into a vast variety of aptasensor platforms for OTA detection. The development of a simple, aptamer-based approach would allow for detection of the toxin without the use of complex analytical instrumentation, which has been the gold standard for OTA detection thus far. However, to date, none of the aptasensor platforms have utilized the natural fluorescence of the phenolic toxin for detection. Herein, we report that OTA binding to OTABA involves π-stacking interactions that lead to GQ-to-toxin energy transfer (ET), which affords a "turn-on" fluorescence self-signaling platform in which the emission of the aptamer-target complex is enhanced in comparison to the free toxin alone. Selective excitation of the GQ-OTA complex at 256 nm leads to a 4-fold enhancement in OTA fluorescence. The GQ-OTA ET detection platform boasts a limit of detection ∼2 ng/mL, which is comparable to a previously demonstrated fluorescence resonance energy transfer immunoassay platform for OTA detection, and displays excellent OTA selectivity and recovery from red wine samples.